Glossary of bird terms#coverts

{{Glossary}}

{{Term|addled eggs|content=addled eggs {{anchor|addled egg|addled|wind egg|wind eggs|hypanema}} }}

{{defn|Also, wind eggs; hypanema.{{cite book|title=Encyclopaedia perthensis, or, Universal dictionary of the arts, sciences, literature, etc.|url=https://books.google.com/books?id=tFYKAQAAMAAJ&pg=PA166|year=1816|publisher=John Brown|location=Edinburgh|page=166}} Eggs that are not viable and will not hatch.{{Harvnb|Weaver|1981|p=12}} See related: {{gli|overbrooding}}.}}

{{Term|afterfeather|content=afterfeather {{anchor|afterfeathers|after feather|after feathers|after-feather|after-feathers}} }}

{{defn|Any structure projecting from the shaft of the {{gli|feather}} at the rim of the {{gli|superior umbilicus}} (at the base of the {{gli|vanes}}), but typically a small area of downy {{gli|barbs}} growing in rows or as tufts.{{efn|Emus and cassowaries are an exception in that their {{gli|afterfeathers}} are neither downy nor diminutive in relation to the vanes, but are comparable in size to them; such feathers are thus sometimes referred to as being "double plumed". The feathers of ostrich and rhea, also flightless birds, are by contrast "soft and filmy" in makeup, lacking any {{gli|barbules}} to add the stiffness needed in working {{gli|flight feathers}}.{{harvnb|Roots|2006|p=16}}}} Entirely absent in some birds—notably from many members of the Columbidae family (pigeons and doves)—afterfeathers can significantly increase the insulative attributes of a bird's {{gli|plumage}}.{{Harvnb|Pettingill|1985|p=32}}}}

{{Term|allopreening|content=allopreening {{anchor|allo-preening|allo preening}} }}

{{Main|Preening#Allopreening}}

{{defn|A form of social grooming among birds, in which one bird {{gli|preen|preens}} another or a pair does so mutually. At times it may be used to redirect or sublimate aggression, such as one bird assuming a solicitation posture to indicate its non-aggression and invite allopreening by the aggressive individual.{{cite book|last=Mandal|first=Fatik Baran|title=Textbook of Animal Behavior|url=https://books.google.com/books?id=FF-LDWalcqEC&pg=PA188|year=2012|publisher=PHI Learning Pvt. Ltd.|location=New Delhi|isbn=978-81-203-4519-5|page=188}}}}

{{Term|alternate plumage|content=alternate plumage {{anchor|alternate plumages|nuptial plumage|nuptial plumages|breeding plumage|breeding plumages}} }}

{{defn|Also, nuptial plumage; breeding plumage. The plumage of birds during the courtship or breeding season. It results from a {{gli|prealternate moult}} that many birds undergo just prior to the season. The alternate plumage is commonly brighter than the {{gli|basic plumage}}, for the purposes of sexual display, but may also be {{gli|cryptic}}, to hide incubating birds that might be vulnerable on the nest.{{cite magazine|magazine=The Auk|date=January 1959|last1=Humphrey|first1=Philip S.|last2=Parkes|first2=Kenneth C.|volume=76|issue= 1|pages=1–31|title=An Approach to the Study of Molts and Plumage|jstor=4081839|doi=10.2307/4081839}}}}

{{Term|altricial|content=altricial {{anchor|semi-altricial|semialtricial|semi altricial}} }}

{{Main|Altricial}}

{{defn|Also defined: semi-altricial; altricial-precocial spectrum. Young that, at hatching, have their eyes closed; are naked or only sparsely covered in {{gli|down feathers}} ({{gli|psilopaedic}}); are not fully able to regulate their body temperature (ectothermic);{{cite book|last1=Summers|first1=Kyle |last2=Crespi|first2=Bernard |title=Human Social Evolution: The Foundational Works of Richard D. Alexander|url=https://books.google.com/books?id=j39rQ9yfwrwC&pg=PT192|year=2013|publisher=Oxford University Press|isbn=978-0-19-933963-1|page=192}} and are unable to walk or leave the nest for an extended period of time to join their parents in {{gli|foraging}} activities ({{gli|nidicolous}}), whom they rely on for food.{{cite book|last=Howell|first=Steve N. G.|title=Peterson Reference Guide to Molt in North American Birds|url=https://books.google.com/books?id=eQU-BAAAQBAJ&pg=PA8|year=2014|publisher=Houghton Mifflin Harcourt|isbn=978-0-547-48769-4|page=8}} The contrasting state is {{gli|precocial}} young, which are born more or less with their eyes open, covered in down, homeothermic, able to leave the nest and ambulate and to participate in foraging.{{cite book|last=Johnston|first=Richard|title=Current Ornithology|url=https://books.google.com/books?id=riYBCAAAQBAJ&pg=PA34|year=2013|publisher=Springer Science & Business Media|isbn=978-1-4615-6781-3|page=34}} The young of many bird species do not precisely fit into either the precocial or altricial category, having some aspects of each and thus fall somewhere on an altricial-precocial spectrum.{{cite book|last=Urfi|first=A. J.|title=The Painted Stork: Ecology and Conservation|url=https://books.google.com/books?id=_9tczTapYXMC&pg=PA88|year=2011|publisher=Springer Science & Business Media|isbn=978-1-4419-8468-5|page=88}} A defined intermediate state is termed semi-altricial, typified by young that, though born covered in down ({{gli|ptilopaedic}}), are unable to leave the nest or walk and are reliant on their parents for food.{{cite book|last=Scott|first=Lynnette|title=Wildlife Rehabilitation|url=https://books.google.com/books?id=FpAOAQAAMAAJ|year=2008|publisher=National Wildlife Rehabilitators Association|isbn=978-1-931439-23-7|page=50}}{{harvnb|Pettingill|2013|p=371}}}}

File:Alula.png

{{Term|alula|content=alula {{anchor|alulae|alulas|bastard wing|bastard wings|bastard-wing|bastard-wings|thumb|thumbs|ala|alular digit|alular digits|alular quill|alular quills}} }}

{{Main|Alula}}

{{defn|Also, bastard wing; alular digit; alular quills. A small, freely-moving projection on the anterior edge of the wing of modern birds (and a few non-avian dinosaurs)—a bird's "thumb"—the word is Latin and means 'winglet'; it is the diminutive of ala, meaning 'wing'. Alula typically bear three to five small {{gli|flight feathers}}, with the exact number depending on the species. The bastard wing normally lies flush against the anterior edge of the wing proper, but can be raised to function in similar manner to the slats of airplane wings that aid in lift by allowing a higher than normal angle of attack. By manipulating the alula structure to create a gap between it and the rest of the wing, a bird can avoid stalling when flying at low speeds or when landing. Feathers on the alular digit are not generally considered to be {{gli|flight feathers}} in the strict sense; though they are asymmetrical, they lack the length and stiffness of most true flight feathers. Nevertheless, alula feathers are a distinct aid to slow flight.}}

{{Term|anisodactylous|content=anisodactylous|anisodactyl|anisodactyl feet|anisodactylous feet|anisodactyl foot|anisodactylous foot}}

{{defn|Descriptive of tetradactyl (four-toed) birds in which the architecture of the foot consists of three toes projecting forward and one toe projecting backward (the {{gli|hallux}}), such as in most {{gli|passerine}} species.{{Harvnb|Pettingill|1985|p=187}}{{Harvnb|Gill|1995|pp=59–61}}}}

{{Term|anting|content=anting {{anchor|ant|bird anting|passive anting}} }}

{{Main|Anting (bird activity)}}

{{defn|Also defined: passive anting. A self-anointing behaviour during which birds rub insects, usually ants and sometimes millipedes, on their {{gli|feathers}} and skin. Anting birds may pick up the insects in their {{gli|bill}} and rub them on their bodies, or may simply lie in an area with a high density of the insects and perform dust bathing-like movements. Insects used for anting secrete chemical liquids such as formic acid, which can act as insecticides, miticides, fungicides and bactericides. The practice may also act to supplement a bird's own preen oil. A third purpose may be to render the insects more palatable, by causing removal of distasteful compounds. More than 200 species of bird are known to ant.{{cite magazine|magazine=The Wilson Bulletin|first=Sophie A. H.|last=Osborn|title=Anting by an American Dipper (Cinclus mexicanus)|volume=110|issue=3|date=September 1998|pages=423–425|url=https://sora.unm.edu/sites/default/files/journals/wilson/v110n03/p0423-p0425.pdf|access-date=2017-01-22|archive-date=2019-11-14|archive-url=https://web.archive.org/web/20191114230458/https://sora.unm.edu/sites/default/files/journals/wilson/v110n03/p0423-p0425.pdf|url-status=live}} "Passive anting" refers to when birds simply position themselves so as to allow insects to crawl through their plumage.}}

File:Gull of Gibraltar (8483055557).jpg (Larus michahellis) in flight. {{gli|Apical spots}} tinge the row of feathers on the trailing edges of its wings.]]

{{Term|apical spot|content=apical spot {{anchor|apical spots|apical-spot|apical-spots}} }}

{{defn|A visible spot near the outer tip of a feather.{{cite book|last1=Alderfer|first1=Jonathan K. |last2=Dunn|first2=Jon|title=National Geographic Birding Essentials: All the Tools, Techniques, and Tips You Need to Begin and Become a Better Birder|url=https://archive.org/details/nationalgeograph00jona|url-access=registration|date=January 2007|publisher=National Geographic|isbn=978-1-4262-0135-6|page=[https://archive.org/details/nationalgeograph00jona/page/216 216]}}}}

{{Term|apterylae|content=apterylae {{anchor|apteria}} }}

{{defn|Singular: apteryla. Also, apteria. Regions of a bird's skin, between the {{gli|pterylae}} (feather tracts), which are free of {{gli|contour feathers}}; {{gli|filoplumes}} and {{gli|down}} may grow in these areas.{{Harvnb|Proctor|Lynch|1998|p=98}}{{cite book|last1=Ulmer|first1=Martin John|last2=Haupt|first2=Robert E.|last3=Hicks|first3=Ellis A.|title=Comparative Chordate Anatomy: A Laboratory Manual|url=https://books.google.com/books?id=Xno_AAAAYAAJ|year=1962|publisher=Harper & Row|page=169}} See related: {{gli|pterylosis}}.}}

{{Term|aviculture|content=aviculture}}

{{Main|Aviculture}}

{{defn|The captive breeding and keeping of birds.}}

{{Term|axilla|content=axilla {{anchor|axillar region|axillar|axillars|underarm|underarms|armpit|arm pit|under arm}} }}

{{defn|Also, axillar region; "underarm"; "armpit". The "armpit" of a bird, often hosting {{gli|covert feathers}} called {{Nowrap|{{gli|axillaries}}.{{Harvnb|Newton, et al.|1899|p=25}}}}}}

{{Term|axillaries|content=axillaries {{anchor|axillary feathers|lower humeral coverts|hypopteron}} }}

{{defn|Also, axillary feathers; lower humeral coverts; hypopteron. {{gli|Covert feathers}} found in the {{gli|axillar region}} or "armpit" of a bird, which are typically long, stiff and white in colour.{{Harvnb|Campbell|Lack|1985|p=60}}}}

{{Glossary end}}

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{{Glossary}}

File:Feather_zipping_microstructure.svg

{{Term|back|content=back {{anchor|backs}} }}

{{defn|The exterior region of a bird's upper parts between the {{gli|mantle}} and the {{gli|rump}}.}}

{{Term|barb|content=barb {{anchor|barbs|ramus|rami}} }}

{{defn|Also defined: ramus (plural: rami). The individual structures growing out of the {{gli|shaft}} that collectively make up the {{gli|vanes}} of the feathers, more or less interconnected by the {{gli|hooklets}} of the {{gli|barbules}}, extending from each side of the distal part of the feather's shaft known as the {{gli|rachis}}. The central axis of a barb is known as the ramus.}}

{{Term|barbules|content=barbules {{anchor|proximal barbules|distal barbules|barbule|barbicel|barbicels|hooklet|hooklets|pennulum|teeth|cilia}} }}

{{defn|Also, radius / radii; tertiary fibres.{{Harvnb|Chandler|1916|p=252}} Also defined: proximal barbules; distal barbules; barbicels; hooklets (hamuli); pennulum; teeth. Just as {{gli|barbs}} branch off on parallel sides of the {{gli|rachis}}, the barbs in turn have a set of structures called barbules, branching from each side of the {{gli|ramus}}. The base cells of the barbule form a plate from which a thinner stalk projects called the pennulum. At one more level of branching, the pennulum hosts small outgrowths from it called barbicels—which when found on {{gli|pennaceous feathers}}, vary in structure depending on which side of a barb's ramus they project from. Proximal barbules (on the proximal side of the ramus) have ventral projections near the base called teeth, while growing from the pennulum are cilia—simple pointed structures. At the base of the proximal barbule, the "dorsal edge is recurved into a {{gli|flange}}".{{Harvnb|Pettingill|1985|pp=32–33}} The distal barbules (on the distal side of the ramus) have a thicker base with more elaborate teeth, and a longer pennulum with hooklets (also called hamuli{{cite book|last=Allen|first=Elsa Guerdrum|title=The History of American Ornithology Before Audubon|url=https://books.google.com/books?id=T4UpAQAAMAAJ|year=1951|publisher=Russell & Russell|page=458}}) at the end, as well as cilia in greater number than on proximal barbules. The hooklets overlap one to four rows of proximal barbules on the next higher barb, locking into their flanges, thereby giving the {{gli|vane}} structure, strength, flexibility and stability. See also: {{gli|friction barbules}}.}}

{{Term|basic plumage|content=basic plumage {{anchor|basic plumages|non-breeding plumage|non-breeding plumages|nonbreeding plumage|nonbreeding plumages|non breeding plumage|non breeding plumages|winter plumage|winter plumages|supplementary plumage|supplementary plumages}} }}

{{defn|Also, winter plumage; non-breeding plumage. Also defined: supplementary plumage. The plumage of birds during the non-breeding season. It results from the {{gli|prebasic moult}} that many birds undergo just after the season, and sometimes (rarely) even a second non-breeding season moult (resulting in what's termed "supplementary plumage") prior to the next breeding season.{{efn|Birds that undergo a second, non-breeding season moult (third moult overall) include: ptarmigans (Lagopus) (in the summer); long-tailed duck (Clangula hyemalis) (in the winter); ruff (Philomachus pugnax) (in the late winter or early spring); and may occur in other members of the sandpiper (Scolopacidae) family.{{Harvnb|Pettingill|1985|pp=189–192}}}} The basic plumage is commonly duller than the {{gli|alternate plumage|alternate or nuptial plumage}}.}}

File:BirdBeaksA.svg

{{Term|beak|content=beak {{anchor|bill|bills|beaks|rostrum|beaked}} }}

{{Main|Beak}}

{{defn|Also, bill or rostrum. An external anatomical structure of a bird's head, roughly corresponding with the "nose" of a mammal, that is used for eating, grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young. Although beaks vary significantly in size and shape from species to species, their underlying structures follow a similar pattern. All beaks are composed of two jaws, generally known as the {{gli|upper mandible}} (or maxilla) and {{gli|lower mandible}} (or mandible),{{Harvnb|Coues|1890|p=198}} covered with a thin, horny sheath of keratin called the {{Nowrap|{{gli|rhamphotheca}},{{Harvnb|Proctor|Lynch|1998|p=66}}{{Harvnb|Gill|1995|p=148}}}} which can be subdivided into the {{gli|rhinotheca}} of the upper mandible and the {{gli|gnathotheca}} of the lower mandible.{{Harvnb|Campbell|Lack|1985|p=47}} The {{gli|tomia}} (singular: tomium) are the cutting edges of the two mandibles.{{Harvnb|Campbell|Lack|1985|p=598}} Most species of birds have external {{gli|nares}} (nostrils) located somewhere on their beak—two holes—circular, oval or slit-like in shape—which lead to the nasal cavities within the bird's skull, and thus to the rest of the respiratory system.{{Harvnb|Campbell|Lack|1985|p=375}} Although the word beak was, in the past, generally restricted to describing the sharpened bills of birds of prey,{{cite book|last=Partington|first=Charles Frederick|title=The British cyclopæedia of natural history: combining a scientific classification of animals, plants, and minerals|url=https://archive.org/details/britishcyclopd02partrich|year=1835|publisher=Orr & Smith|page=[https://archive.org/details/britishcyclopd02partrich/page/417 417]}} in modern ornithology, the terms beak and bill are generally used synonymously.}}

{{Term|beak colour|content=beak colour {{anchor|beak colours|beak colouring|beak color|beak colors|beak coloring}} }}

{{Main|Beak#Color}}

{{defn|The colour of a bird's beak results from concentrations of pigments—primarily melanins and carotenoids—in the epidermal layers, including the {{gli|rhamphotheca}}.{{cite magazine|magazine=American Zoologist|volume=9|issue= 2|pages=521–530|title=The Control of Color in Birds|date=May 1969|first=Charles L.|last=Ralph|jstor=3881820|doi=10.1093/icb/9.2.521|pmid=5362278|doi-access=free}} In general, beak colour depends on a combination of the bird's hormonal state and diet. Colours are typically brightest as the breeding season approaches and palest after breeding.}}

{{Term|beak trimming|content=beak trimming {{anchor|debeaking|coping}} }}

{{Main|Debeaking}}

{{defn|Also, debeaking and coping. The partial removal of the {{gli|beak}} of poultry, especially layer hens and turkeys, although it may also be performed on quail and ducks. Because the beak is a sensitive organ with many sensory receptors, beak trimming or debeaking is "acutely painful"{{cite book |title=Improving Animal Welfare: A Practical Approach |first=Temple |last=Grandin |publisher=CABI |location=Oxfordshire, UK |year=2010 |page=110 |isbn=978-1-84593-541-2}} to the birds it is performed on. It is nonetheless routinely done to intensively farmed bird species, because it helps reduce the damage the flocks inflict on themselves due to a number of stress-induced behaviours, including cannibalism, {{gli|vent pecking}} and {{gli|feather pecking}}. A cauterizing blade or infrared beam is used to cut off about half of the upper beak and about a third of the lower beak. Pain and sensitivity can persist for weeks or months after the procedure, and neuromas can form along the cut edges. Food intake typically decreases for some period after the beak is trimmed. However, studies show that trimmed poultry's adrenal glands weigh less, and their plasma corticosterone levels are lower than those found in untrimmed poultry, indicating that they are less stressed overall. A less radical, separate practice, usually performed by an avian veterinarian or an experienced birdkeeper, involves clipping, filing or sanding the beaks of captive birds for health purposes—in order to correct or temporarily alleviate overgrowths or deformities and better allow the bird to go about its normal feeding and preening activities.{{cite web|title=Bird Beaks: Anatomy, Care, and Diseases|url=http://www.peteducation.com/article.cfm?c=15+1829&aid=2752|publisher=Veterinary & Aquatic Services Department, Drs. Foster & Smith|access-date=January 29, 2017|archive-url=https://web.archive.org/web/20120604232117/http://www.peteducation.com/article.cfm?c=15+1829&aid=2752|archive-date=June 4, 2012|url-status=dead}} "Coping" is the name for this practice amongst raptor keepers.{{cite web|last=Ash|first=Lydia|title=Coping your Raptor|url=http://www.themodernapprentice.com/coping.htm|publisher=The Modern Apprentice|access-date=January 29, 2017|archive-date=April 6, 2005|archive-url=https://web.archive.org/web/20050406015859/http://themodernapprentice.com/coping.htm|url-status=live}}}}

{{Term|belly|content=belly {{anchor|abdomen|abdomens|bellies}} }}

{{defn|Also, abdomen. The {{gli|topography|topographical}} region of a bird's {{gli|underparts}} between the posterior end of the breast and the {{gli|vent}}.{{cite book|last1=Baird|first1=Spencer Fullerton|last2=Brewer|first2=Thomas Mayo|last3=Ridgway|first3=Robert|title=A History of North American Birds|url=https://books.google.com/books?id=PF8MAQAAIAAJ&pg=PA554|year=1874|publisher=Little, Brown|page=535}}}}

{{Term|billing|content=billing {{anchor|nebbing}} }}

{{defn|Also, nebbing (chiefly UK). Describes the tendency of mated pairs of many bird species to touch or clasp each other's {{gli|bills}}.{{Cite news |url=https://www.chicagotribune.com/2004/08/12/add-this-to-life-list-birding-has-inspired-flock-of-words/ |title=Add this to life list: 'Birding' has inspired flock of words |first=Nathan |last=Bierma |newspaper=Chicago Tribune |date=August 12, 2004 |access-date=2017-01-20 |archive-date=2012-08-12 |archive-url=https://web.archive.org/web/20120812104405/http://articles.chicagotribune.com/2004-08-12/features/0408120087_1_catholic-cardinals-billing-cain-and-abel |url-status=live }} This behaviour appears to strengthen pair bonding.{{harvnb|Terres|1980|p=232}} The amount of contact involved varies among species. Some gently touch only a part of their partner's beak while others clash their beaks vigorously together.{{cite book |title=Biology of Marine Birds |editor1-first=Elizabeth Anne |editor1-last=Schreiber |editor2-first=Joanna |editor2-last=Burger |year=2002 |location=Boca Raton, FL |publisher=CRC Press |isbn=978-0-8493-9882-7 |page=325}}}}

{{Term|bill tip organ|content=bill tip organ {{anchor|bill tip organs|billtip organ|billtip-organbilltip-organs|bill-tip organ|bill-tip organs}} }}

{{Main|Beak#Bill tip organ}}

{{defn|A region found near the tip of the {{gli|bill}} in several types of birds that forage particularly by probing. The region has a high density of nerve endings known as the {{gli|corpuscles of Herbst}}. These consist of pits in the bill's surface lined with cells that sense pressure changes. The assumption is that these cells allow a bird to perform "remote touch", meaning that it can detect the movement of animals by pressure variations in water, without directly touching the prey. Bird species known to have bill-tip organs include ibises, shorebirds of the family Scolopacidae and kiwis.{{cite magazine|first1=Susan J.|last1=Cunningham|first2=Maurice R.|last2=Alley|first3=Isabel|last3=Castro|first4=Murray A.|last4=Potter|first5=Malcolm|last5=Cunningham|first6=Michael J.|last6=Pyne|title=Bill morphology of Ibises suggests a remote-tactile sensory system for prey detection|magazine=The Auk|year=2010|volume=127|issue= 2|pages=308–316|doi=10.1525/auk.2009.09117|s2cid=85254980}}}}

File:Pitta guajana-20030531.jpg (Hydrornis guajanus), with a numbered ring {{gli|banding}} its left leg]]

{{Term|bird ringing|content=bird ringing {{anchor|bird banding|ringing|banding}} }}

{{Main|Bird ringing}}

{{defn|Also, bird banding. The attachment of small, individually numbered metal or plastic tags to the legs or wings of wild birds to enable individual identification. The practice helps in keeping track of bird movement and life history. Upon capture for ringing, it is common to take measurements and examine the conditions of feather {{gli|moult}}, amount of subcutaneous fat, age indications and sex. The subsequent recapture or recovery of banded birds can provide information on migration, longevity, mortality, population, territoriality, feeding behaviour and other aspects that are studied by ornithologists. Bird ringing is the term used in the UK and in some other parts of Europe, while the term bird banding is more often used in the U.S. and Australia.{{cite book|last1=Busse|first1=Przemyslaw|last2=Meissner|first2=Wlodzimierz|title=Bird Ringing Station Manual|url=https://books.google.com/books?id=VxHuCAAAQBAJ|year=2015|publisher=De Gruyter|location=Warsaw|isbn=978-83-7656-053-3}}}}

{{Term|bird strike|content=bird strike {{anchor|bird strikes}} }}

{{defn|The impact of a bird or birds with an airplane in flight.{{Harvnb|Weaver|1981|p=23}}}}

{{Term|body down|content=body down {{anchor|body-down|body-down feather|body-down feathers|body down feather|body down feathers}} }}

{{defn|The layer of small, fluffy {{gli|down}} feathers that lie underneath the outer {{gli|contour feathers}} on a bird's body.{{Harvnb|Sibley, et al.|2001|p=17}} Compare: {{gli|natal down}} and {{gli|powder down}}.}}

{{Term|breast|content=breast {{anchor|breasts}} }}

{{defn|The {{gli|topography|topographical}} region of a bird's external anatomy between the {{gli|throat}} and the {{gli|belly}}.{{Harvnb|Weaver|1981|p=24}}}}

{{Term|breeding plumage}}

{{defn|See {{gli|alternate plumage}}.}}

{{Term|brood|content=brood {{anchor|broods}} }}

{{defn|The collective term for the offspring of birds, or the act of {{gli|egg incubation|brooding}} the eggs.{{cite book|editor-last=Vuilleumier|editor-first=françois|title=American Museum of Natural History Birds of North America Eastern Region|url=https://books.google.com/books?id=yRFpR-D2O1sC&pg=RA24-PA473|year=2011|publisher=DK Publishing|isbn=978-0-7566-7387-1|page=473}}}}

{{Term|brooding}}

{{defn|See {{gli|egg incubation}}.}}

{{Term|broodiness|content=broodiness {{anchor|broody}} }}

{{Main|Broodiness}}

{{defn|Also defined: broody. The action or behavioural tendency of a bird to sit on a {{gli|clutch}} of eggs to {{gli|egg incubation|incubate}} them, often requiring the non-expression of many other behaviours including feeding and drinking.{{cite book|last1=Ranquini|first1=Juan Homedes|last2=Garcia|first2=Francisco Haro|title=Zoogenética|url=https://books.google.com/books?id=vRVBAAAAYAAJ|year=1958|publisher=Salvat}} The adjective "broody" is defined as "[b]eing in a state of readiness to brood eggs that is characterized by cessation of laying and by marked changes in behavior and physiology". Example usage: "a broody hen".{{cite web|url=http://www.merriam-webster.com/dictionary/broody|title=Merriam-Webster definition|access-date=March 12, 2017|archive-date=March 26, 2017|archive-url=https://web.archive.org/web/20170326135544/https://www.merriam-webster.com/dictionary/broody|url-status=live}} }}

{{Term|brood patch|content=brood patch {{anchor|brood patches}} }}

{{defn|A bare patch of skin that most female birds gain during the nesting season for thermoregulation purposes, by shedding feathers close to the belly, in an area that will be in contact with the eggs during {{gli|incubation}}. The patch of bare skin is well supplied with blood vessels at the surface, facilitating heat transfer to the eggs.{{cite magazine|last=Turner|first=J. Scott|year=1997|title=On the thermal capacity of a bird's egg warmed by a brood patch|magazine=Physiological Zoology |volume=70|issue= 4|pages=470–80|doi=10.1086/515854|pmid=9237308}}}}

{{Term|brood parasite|content=brood parasite {{anchor|brood parasites|brood parasitism}} }}

{{Main|Brood parasite}}

{{defn|Birds, such as the common goldeneye, indigobirds, whydahs, honeyguides, cowbirds and New World cuckoos, that lay their eggs in other birds' nests, in order to have their chicks {{gli|incubated}} through {{gli|fledging}} by the parents of another bird, often of another species.{{cite magazine | last1=Aragon| first1=S.|last2=Møller | first2=A. P.|last3=Soler|first3=J. J.|last4=Soler|first4=M.|year=1999|title=Molecular phylogeny of cuckoos supports a polyphyletic origin of brood parasitism|magazine=Journal of Evolutionary Biology|volume=12|issue= 3|pages=495–506|doi=10.1046/j.1420-9101.1999.00052.x| s2cid=16923328}}{{cite magazine|last1=Sorenson|first1=M.D.|last2=Payne|first2=R.B.|year=2001|title=A single ancient origin of brood parasitism in African finches: implications for host-parasite coevolution|magazine=Evolution|volume=55|issue= 12|pages=2550–2567| doi=10.1554/0014-3820(2001)055[2550:asaoob]2.0.co;2|pmid=11831669|hdl=2027.42/72018|url=https://deepblue.lib.umich.edu/bitstream/2027.42/72018/1/j.0014-3820.2001.tb00768.x.pdf}}{{cite magazine|last1=Sorenson|first1=M.D. |last2=Payne|first2=R.B.|year=2002|title=Molecular genetic perspectives on avian brood parasitism|magazine=Integrative and Comparative Biology|volume=42|issue= 2|pages=388–400|doi=10.1093/icb/42.2.388|pmid=21708732|doi-access=free}}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|calamus|content=calamus {{anchor|calami}} }}

{{defn|Plural: calami. The basal part of the {{gli|quill}} of {{gli|pennaceous feathers}}, which embeds at its proximal tip in the skin of a bird. The calamus is hollow and has pith formed from the dry remains of the feather pulp. The calamus stretches between two openings—at its base is the {{gli|inferior umbilicus}} and at its distal end is the {{gli|superior umbilicus}}; the {{gli|rachis}} of the stem, hosting the {{gli|vanes}}, continues above it. Calamus derives from the Latin for 'reed' or 'arrow'.{{cite web|url=http://www.latin-dictionary.net/search/latin/calamus|title=Latin Dictionary|access-date=May 1, 2020|archive-date=October 16, 2021|archive-url=https://web.archive.org/web/20211016050502/http://www.latin-dictionary.net/search/latin/calamus|url-status=live}}}}

{{Birdsong|url=http://www.xeno-canto.org/explore?query=Gaviidae|species=loons|song1=loons.ogg|caption song1=The haunting {{gli|call}} of the loon}}

{{Term|call|content=call {{anchor|calls|alarm call|alarm calls|mobbing call|mobbing calls|duet call|diet calls|food begging call|food begging calls|antiphonal duetting|antiphonal|antiphonal duet|flight call|flight calls|calling}} }}

{{Main|Bird vocalization}}

{{defn|Specific types: alarm; contact; duet; antiphonal duetting; food begging; flight; mobbing. A type of bird vocalization tending to serve such functions as giving alarm or keeping members of a flock in contact—as opposed to a bird's {{gli|song}}, which is longer, more complex and is usually associated with courtship and mating.{{cite web|last1=Ehrlich|first1=Paul R.|last2=Dobkin|first2=David S.|last3=Wheye|first3=Darryl|url=https://web.stanford.edu/group/stanfordbirds/text/uessays/essays_alpha.html|title="Bird Voices" and "Vocal Development" from Birds of Stanford essays|access-date=9 September 2008|archive-date=25 July 2018|archive-url=https://web.archive.org/web/20180725012231/http://web.stanford.edu/group/stanfordbirds/text/uessays/essays_alpha.html|url-status=live}} Individual birds may be sensitive enough to identify each other through their calls. Many birds that nest in colonies can locate their chicks using their calls.{{cite magazine|last1=Lengagne|first1=T.|last2=Lauga|first2=J.|last3=Aubin|first3=T.|year=2001|title=Intra-syllabic acoustic signatures used by the King Penguin in parent-chick recognition: an experimental approach|magazine=The Journal of Experimental Biology|volume=204|pages=663–672|url=http://jeb.biologists.org/cgi/reprint/204/4/663.pdf|pmid=11171348|issue=Pt. 4|access-date=2017-04-01|archive-date=2007-09-30|archive-url=https://web.archive.org/web/20070930043626/http://jeb.biologists.org/cgi/reprint/204/4/663.pdf|url-status=live}} Alarm calls are used to sound alarm to other individuals. Food-begging calls are made by baby birds to beg for food, such as the "wah" of infant blue jays.{{cite book|last=MacKay|first=Barry Kent|title=Bird Sounds: How and why Birds Sing, Call, Chatter, and Screech|url=https://books.google.com/books?id=LsTZcR92uPgC&pg=PA28|date=January 2001 |publisher=Stackpole Books|isbn=978-0-8117-2787-7|page=28}} Mobbing calls signal other individuals in mobbing species while harassing a predator. They differ from alarm calls, which alert other species members to allow escape from predators. As an example, the great tit, a European songbird, uses such a signal to call on nearby birds to harass a perched bird of prey, such as an owl. This call occurs in the 4.5kHz range,{{cite book|last=Alcock|first=John|author-link=John Alcock (behavioral ecologist)|year=1998|title=Animal Behavior: An Evolutionary Approach|edition=6th|publisher=Sinauer Associates|location=Sunderland|isbn=978-0-87893-009-8|url=https://archive.org/details/animalbehaviorev00alco_1}} and carries over long distances. However, when such prey species are in flight, they employ an alarm signal in the 7–8 kHz range. This call is less effective at traveling great distances, but is much more difficult for both owls and hawks to hear (and detect the direction from which the call came).{{cite magazine|last=Brown|first=C. H.|year=1982|title=Ventriloquial and locatable vocalizations in birds|magazine=Zeitschrift für Tierpsychologie | volume=59|issue= 4|pages=338–350|doi=10.1111/j.1439-0310.1982.tb00346.x}} Contact calls are used by birds for the purpose of letting others of their species know their location. Relatedly, flight calls are vocalizations made by birds while flying, which often serve to keep flocks together.{{Harvnb|Sibley, et al.|2001|pp=68–69}} These calls are also used for when birds want to alert others that they are taking flight.{{cite book|last=Rowinski|first=Kate|title=The Joy of Birding: A Beginner's Guide|url=https://books.google.com/books?id=Ise4k6tJpQAC&pg=PA22|year=2011|publisher=Skyhorse Publishing Inc.|isbn=978-1-61608-122-5|pages=22–}} Many birds engage in duet calls—a call made by two birds at or nearly at the same time. In some cases, the duets are so perfectly timed as to appear almost as one call. This kind of calling is termed antiphonal duetting.{{cite magazine|author=Thorpe, W. H.|magazine=Nature|volume=197|pages=774–776|year=1963|doi=10.1038/197774a0|title=Antiphonal Singing in Birds as Evidence for Avian Auditory Reaction Time|issue= 4869|bibcode=1963Natur.197..774T|s2cid=30542781}} Such duetting is noted in a wide range of families including quails,{{cite magazine|last1=Stokes|first1=A. W.|last2=Williams|first2=H. W.|year=1968|title=Antiphonal calling in quail|magazine=Auk|volume=85|issue=1|pages=83–89|url=http://sora.unm.edu/sites/default/files/journals/auk/v085n01/p0083-p0089.pdf|doi=10.2307/4083626|jstor=4083626|access-date=2017-04-01|archive-date=2014-04-29|archive-url=https://web.archive.org/web/20140429184104/http://sora.unm.edu/sites/default/files/journals/auk/v085n01/p0083-p0089.pdf|url-status=live}} bushshrikes,{{cite book|last1=Harris|first1=Tony |last2=Franklin|first2=Kim|title=Shrikes and Bush-Shrikes|publisher=Princeton University Press|pages=257–260|isbn=978-0-691-07036-0|year=2000}} babblers such as scimitar babblers and some owls{{cite magazine|last=Osmaston|first=B. B.|year=1941|title='Duetting' in birds|magazine=Ibis|volume=5| pages=310–311|doi=10.1111/j.1474-919X.1941.tb00620.x|issue= 2}} and parrots.{{cite magazine|last=Power|first=D. M.|year=1966|title=Antiphonal duetting and evidence for auditory reaction time in the Orange-chinned Parakeet|magazine=Auk|volume=83|issue= 2|pages=314–319|doi=10.2307/4083033|jstor=4083033}}}}

File:Balck Heron canopy crop.jpg

{{Term|canopy feeding|content=canopy feeding {{anchor|canopy feeding|double-wing feeding|double wing feeding}} }}

{{defn|Also defined: double-wing feeding. Some herons, such as the black heron, adopt an unusual position while hunting for prey. With their head held down in a hunting position, they sweep their wings forward to meet in front of their head, thereby forming an umbrella shaped canopy. To achieve full canopy closure, the primaries and secondaries touch the water, the {{gli|nape}} feathers are erected and the tail is drooped. The bird may take several strides in this position. One theory about the function of this behaviour is that it reduces glare from the water surface, allowing the bird to more easily locate and catch prey. Alternatively, the shade provided by the canopy may attract fish making their capture easier. Some herons adopt a similar behaviour called double-wing feeding in which the wings are swept forward to create an area of shade, though a canopy is not formed.{{cite book|last1=Hancock|first1=James|last2= Kushlan|first2=James|title=The Herons Handbook|publisher=A&C Black|year=2010|pages=20, 101–102|isbn=978-1-4081-3496-2| url=https://books.google.com/books?id=ldzxpcqepksC&pg=PT139|location=London}}}}

{{Term|carpal bar|content=carpal bar {{anchor|carpal-bar|carpal bars|carpal-bars}} }}

{{defn|A patch seen on the {{gli|upperwing}} of some birds that usually appears as a long stripe or line. It is created by the contrast between the greater coverts and the other wing feathers.{{Harvnb|Floyd|2008|p=495}}}}

{{Term|caruncle|content=caruncle {{anchor|caruncles|dewlap|dewlaps|ear lobe|er lobes|nodule|nodules}} }}

{{defn|The collective term for the several fleshy protuberances on the heads and throats of gallinaceous birds, i.e., {{gli|combs}}, {{gli|wattles}}, ear lobes and nodules. They can be present on the head, neck, {{gli|throat}}, {{gli|cheeks}} or around the eyes of some birds. Caruncles may be featherless, or present with a small array of scattered feathers. In some species, they may form pendulous structures of erectile tissue, such as the "snood" of the domestic turkey.{{cite book|title=Catalogue of the birds in the British Museum|publisher=British Natural History Museum Department of Zoology|last1=Sharpe|first1=Richard Bowdler|year=1888}}{{cite book|title=The Birds of America|publisher=Dover Publications |last1=Audubon|first1=John James|last2=Amadon|first2=Dean|last3=Bull|first3=John L.|year=1967|oclc=555150}} While caruncles are ornamental elements used by males to attract females to breed,{{cite book|url=https://books.google.com/books?id=MMMjW6AuzHAC&pg=PA702|title=The Complete Burke's Backyard: The Ultimate Book of Fact Sheets|last1=Burke|first1=Don|page=702|isbn=9781740457392|year=2005|publisher=Allen & Unwin }} it has been proposed that these organs are also associated with genes that encode resistance to disease,{{cite magazine|last1=Baratti|first1=Mariella|last2=Ammannati|first2=Martina|last3=Magnelli|first3=Claudia|last4=Massolo|first4=Alessandro|last5=Dessì-Fulgheri|first5=Francesco|title=Are large wattles related to particular MHC genotypes in the male pheasant?|magazine=Genetica|volume=138|issue= 6|year=2010|pages=657–665| issn=0016-6707|doi=10.1007/s10709-010-9440-5|pmid=20145977|s2cid=35053439}} and for birds living in tropical regions, that caruncles also play a role in thermoregulation by making the blood cool faster when flowing through them.{{cite magazine|magazine=The Auk|year=1996|last1=Buchholz|first1=Richard|url=https://sora.unm.edu/sites/default/files/journals/auk/v113n02/p0310-p0318.pdf|volume=113|issue=2|pages=310–318|title=Thermoregulatory Role of the Unfeathered Head and Neck in Male Wild Turkeys|doi=10.2307/4088897|jstor=4088897|access-date=2017-02-11|archive-date=2014-05-18|archive-url=https://web.archive.org/web/20140518135837/https://sora.unm.edu/sites/default/files/journals/auk/v113n02/p0310-p0318.pdf|url-status=live}}}}

File:Aceros cassidix -Vogelpark Walsrode -pair-8a.jpgs with prominent {{gli|casques}} on display]]

{{Term|casque|content=casque {{anchor|casques}} }}

{{Main|Casque (anatomy)}}

{{defn|A horny ridge found on the {{gli|upper mandible}} of a bird's bill, especially used in relation to hornbills and cassowaries,{{cite book|last=Blake|first=Emmet Reid|title=Manual of Neotropical Birds|url=https://books.google.com/books?id=YP0AX3LW8jYC&pg=PA428|year=1977|publisher=University of Chicago Press|isbn=978-0-226-05641-8|page=428}}{{cite book|last1=Pratt|first1=Thane K.|last2=Beehler|first2=Bruce M.|title=Birds of New Guinea|url=https://books.google.com/books?id=SBn8AwAAQBAJ&pg=PA262|edition=2nd|year=2014|publisher=Princeton University Press|location=Oxford|isbn=978-1-4008-6511-6|page=262}} though other birds may have casques such as common moorhens,{{cite book|last1=Reilly|first1=Edgar M.|author2=National Audubon Society|title=The Audubon illustrated handbook of American birds|url=https://archive.org/details/audubonillustrat00reil|url-access=registration|year=1968|publisher=McGraw-Hill|page=[https://archive.org/details/audubonillustrat00reil/page/142 142]}} tufted puffins{{cite book|last=Stejneger|first=Leonhard Hess|title=Results of Ornithological Explorations in the Commander Islands and in Kamtschatka|url=https://archive.org/details/resultsornithol00stejgoog|year=1885|publisher=U.S. Government Printing Office|pages=[https://archive.org/details/resultsornithol00stejgoog/page/n61 52]–53}} and (male) friarbirds.{{cite book|author=National Geographic Society|editor-last1=Harris|editor-first1=Tim|title=Complete Birds of the World|url=https://books.google.com/books?id=0TIiIdLp9xkC&pg=PA226|year=2009|publisher=National Geographic|isbn=978-1-4262-0403-6|page=226}} The ridge line on the {{gli|upper maxilla}} may extend to a prominent crest on the front of the face and on the head, such as in the "flamboyant" crest of the rhinoceros hornbill.{{Harvnb|Mobley, et al.|2008|p=339}} Some hornbill casques contain a hollow space that may act as a resonance chamber, amplifying {{gli|calls}}.{{Harvnb|Carnaby|2008|p=124}} Similar function has been proposed for cassowary casques, as well as for protection of the head while dense vegetation is traversed, as a sexual ornament and for use as a "shovel" for digging food.{{Harvnb|Mobley, et al.|2008|p=441}} Compare: {{gli|frontal shield}}.}}

{{Term|cere|content=cere {{anchor|ceres}} }}

{{Main|Beak#Cere}}

{{defn|From the Latin cera meaning 'wax', a waxy structure which covers the base of the {{gli|bills}} of some bird species from a handful of families—including raptors, owls, skuas, parrots, turkeys and curassows. The cere structure typically contains the {{gli|nares}}, except in owls, where the nares are distal to the cere. Although it is sometimes feathered in parrots,{{cite book|first1=Tony |last1=Jupiter|first2=Mike|last2=Parr|page=17|title=Parrots: A Guide to Parrots of the World|url=https://books.google.com/books?id=kqYmmbZXlOkC|year=2010|publisher=A&C Black|isbn=978-1-4081-3575-4}} the cere is typically bare and often brightly coloured. In raptors, the cere is a sexual signal which indicates the "quality" of a bird; the orangeness of a Montague's harrier's cere, for example, correlates to its body mass and physical condition.{{cite magazine|magazine=Biology Letters|first1=François|last1=Mougeo|first2=Beatriz E.|last2=Arroyo|title=Ultraviolet reflectance by the cere of raptors |date=June 22, 2006|volume=2|issue= 2|pages=173–176|doi=10.1098/rsbl.2005.0434 |pmid=17148356|pmc=1618910}} The colour or appearance of the cere can be used to distinguish between males and females in some species. For example, the male great curassow has a yellow cere, which the female (and young males) lack,{{cite book |title=Wildlife of Mexico: The Game Birds and Mammals|publisher=University of California Press|isbn=978-0-520-00724-6|year=1972|page=[https://archive.org/details/wildlifeofmexico00leop/page/202 202]|first=Aldo Starker|last=Leopold|location=Berkeley, CA|url=https://archive.org/details/wildlifeofmexico00leop/page/202}} and the male budgerigar's cere is blue, while the female's is pinkish or brown.{{cite book |title=A Birdkeeper's Guide to Budgies |first= David |last=Alderton |year=1996 |publisher=Tetra Press | page=12}}}}

{{Term|cheek|content=cheek {{anchor|malar|malars|cheeks|malar region}} }}

{{defn|Also, malar / malar region. The area of the sides of a bird's head, behind and below the eyes.}}

{{Term|chin|content=chin {{anchor|chins}} }}

{{defn|A small feathered area located just below the base of the {{gli|bill}}'s {{gli|lower mandible}}.{{Harvnb|Vinicombe|2014|p=14}}}}

{{Term|cloaca|content=cloaca {{anchor|cloacas|cloacae}} }}

{{defn|A multi-purpose opening terminating at the {{gli|vent}} at the posterior of a bird: birds expel waste from it; most birds mate by joining cloaca (a "{{gli|cloacal kiss}}"); and females lay eggs from it. Birds do not have a urinary bladder or external urethral opening and (with exception of the ostrich) uric acid is excreted from the cloaca, along with faeces, as a semisolid waste.{{cite web |last1=Ehrlich |first1=Paul R. |last2=Dobkin |first2=David S. |last3=Wheye |first3=Darryl |title=Drinking |url=http://www.stanford.edu/group/stanfordbirds/text/essays/Drinking.html |year=1988 |work=Birds of Stanford |publisher=Stanford University |access-date=January 29, 2017 |archive-date=May 2, 2006 |archive-url=https://web.archive.org/web/20060502012513/http://www.stanford.edu/group/stanfordbirds/text/essays/Drinking.html |url-status=live }}{{cite magazine|last1=Tsahar|first1=Ella|title=Can birds be ammonotelic? Nitrogen balance and excretion in two frugivores|magazine=Journal of Experimental Biology|volume=208|issue= 6|pages=1,025–34|year=2005|pmid=15767304 |doi=10.1242/jeb.01495 |last2=Martínez Del Rio|first2=C.|last3=Izhaki|first3=I.|last4=Arad |first4=Z.|doi-access=free}}{{cite journal|doi= 10.1016/S1095-6433(03)00006-0|last1= Skadhauge|first1= E.|last2=Erlwanger|first2=K.H.|last3= Ruziwa|first3=S.D.|last4=Dantzer|first4=V. |last5=Elbrønd| first5=V.S.|last6=Chamunorwa|first6=J.P.|title=Does the ostrich (Struthio camelus) coprodeum have the electrophysiological properties and microstructure of other birds?|journal= Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology|volume=134|issue= 4|pages=749–755|year= 2003 |pmid=12814783 }} Additionally, in those few bird species in which males possess a penis (Palaeognathae [with the exception of the kiwis], the Anseriformes [with the exception of screamers] and in rudimentary forms in Galliformes{{cite web|last=Yong |first=Ed |url=http://phenomena.nationalgeographic.com/2013/06/06/how-chickens-lost-their-penises-ducks-kept-theirs/ |archive-url=https://web.archive.org/web/20130609052803/http://phenomena.nationalgeographic.com/2013/06/06/how-chickens-lost-their-penises-ducks-kept-theirs/ |url-status=dead |archive-date=June 9, 2013 |title=Phenomena: Not Exactly Rocket Science How Chickens Lost Their Penises (And Ducks Kept Theirs) |date=6 June 2013 |publisher=Phenomena.nationalgeographic.com |access-date=January 29, 2017}}{{cite web |url=http://bcs.whfreeman.com/gill/bcs-pages/body-right_10.asp?s=10000&n=00010&i=99010.06&v=chapter&o=%7C13000%7C00010%7C&ns=undefined |title=Ornithology, 3rd Edition – Waterfowl: Order Anseriformes |access-date=January 29, 2017 |url-status=dead |archive-url=https://web.archive.org/web/20150622030534/http://bcs.whfreeman.com/gill/bcs-pages/body-right_10.asp?s=10000&n=00010&i=99010.06&v=chapter&o=%7C13000%7C00010%7C&ns=undefined |archive-date=June 22, 2015 }}) it is hidden within the proctodeum compartment within the cloaca, just inside the vent.{{Harvnb|Pettingill|1985|p=376}}}}

{{Term|cloacal kiss|content=cloacal kiss {{anchor|cloacal contact}} }}

{{defn|Most male birds lack a phallus and instead have erectile genital papilla at the terminus of their vas deferens. When male and female birds of such species copulate, they each evert and then press together, or "kiss" their respective proctodeum (the lip of the cloaca). Upon the clocal kiss, the male's sperm spurts into the female's urodoeum (a compartment inside the {{gli|cloaca}}), which then make their way into the oviduct.{{cite book|last=Maxwell|first=Kenneth E.|title=The Sex Imperative: An Evolutionary Tale of Sexual Survival|url=https://books.google.com/books?id=dnf1BwAAQBAJ&pg=PA99|year=2013|publisher=Springer|isbn=978-1-4899-5988-1|page=99}}{{cite book|last=Doneley|first=Bob|title=Avian Medicine and Surgery in Practice: Companion and Aviary Birds, Second Edition|url=https://books.google.com/books?id=xQrYCwAAQBAJ&pg=PA12|year=2016|publisher=CRC Press|isbn=978-1-4822-6019-9|page=12}}}}

{{Term|clutch|content=clutch {{anchor|clutches}} }}

{{main|Clutch (eggs)}}

{{defn|All of the eggs produced by birds often at a single time in a {{gli|nest}}. Clutch size differs greatly between species, sometimes even within the same genus. It may also differ intraspecies due to many factors including habitat, health, nutrition, predation pressures and time of year.{{cite magazine|magazine=The Ibis|last1=Lack|first1=David|year=1947|pages=302–352|title=The significance of clutch-size (part I-II)|volume=89|issue= 2|url=https://books.google.com/books?id=TaYfZBU11ZoC|orig-date=1887|doi=10.1111/j.1474-919X.1947.tb04155.x}} Average clutch size ranges from one (as in northern gannet{{Harvnb|Pettingill|1985|p=310}}) to about 17 (as in grey partridge{{cite book|last=McCabe|first=Robert A.|title=Hungarian partridge (perdix perdix linn.) studies in Wisconsin|url=https://books.google.com/books?id=Vkc7AAAAMAAJ|year=1943|publisher=University of Wisconsin—Madison|page=28}}).}}

File:Rooster portrait2.jpg

{{Term|comb|content=comb {{anchor|coxcomb|combs|coxcombs}} }}

{{Main|Comb (anatomy)}}

{{defn|Also, cockscomb (coxcomb and other sp. variants). A fleshy growth or crest on the top of the head of gallinaceous birds, such as turkeys, pheasants and domestic chickens. Its alternative name, cockscomb (or coxcomb) reflects that combs are generally larger on males than on females (a male gallinaceous bird is called a cock). Comb shape varies considerably depending on the breed or species of bird. The "comb" most often refers to chickens in which the most common shape is the "single comb" of a rooster from breeds such as the leghorn. Other common comb types are the "rose comb" of, e.g., the eponymous rosecomb; the "pea comb" of, e.g., the brahma and araucana; and others.{{cite magazine|last=Anderson|first=Dave|magazine=Backyard Poultry Magazine|title=The Chicken's Comb|date=February–March 2008}}}}

{{Term|colony|content=colony {{anchor|colonies|colonial|seabird colony|seabird colonies|breeding colony|breeding colonies|communal roost|communal roosts|communal roosting|heronries|heronry|rookery|rookeries}} }}

{{Main|Bird colony|Communal roosting|Heronry|Rookery}}

{{defn|Also defined: seabird colony; breeding colony; communal roost; heronries; rookery. A large congregation of individuals of one or more species of bird that nest or roost in proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony. A group of birds congregating for rest is called a communal roost. Approximately 13% of all bird species nest colonially.{{Harvnb|Gill|1995|pp=138–141 }} Nesting colonies are very common among seabirds on cliffs and islands. Nearly 95% of seabirds are colonial,{{cite magazine|doi=10.1016/S0169-5347(97)01124-5|pmid=21238100|last1=Danchin|first1=E.|last2=Wagner|first2=R.H.|title=The evolution of coloniality: the emergence of new perspectives|magazine=Trends in Ecology and Evolution|volume=12|issue=2|pages=342–347|year=1997|url=http://www.univet.hu/users/jkis/education/Visokol/Coloniality.pdf|access-date=2017-04-01|archive-date=2011-10-03|archive-url=https://web.archive.org/web/20111003160047/http://www.univet.hu/users/jkis/education/Visokol/Coloniality.pdf|url-status=dead}} leading to the usage, seabird colony, sometimes called a rookery. Many species of terns nest in colonies on the ground. Herons, egrets, storks and other large waterfowl also nest communally in what are called heronries. Colony nesting may be an evolutionary response to a shortage of safe nesting sites and abundance or unpredictable food sources which are far away from the nest sites.{{cite magazine|doi=10.1086/286137|last1=Rolland|first1=Cecile|last2=Danchin|first2=Etienne|last3=de Fraipont|first3=Michelle|title=The Evolution of Coloniality in Birds in Relation to Food, Habitat, Predation, and Life-History Traits: A Comparative Analysis|magazine=The American Naturalist|volume=151|issue= 6|pages=514–529|year=1998|url=http://www.biosci.missouri.edu/avianecology/courses/avianecology/readings/Rolland_C_1998.pdf|pmid=18811373|url-status=dead|archive-url=https://web.archive.org/web/20100620170547/http://www.biosci.missouri.edu/avianecology/courses/avianecology/readings/Rolland_C_1998.pdf|archive-date=June 20, 2010}}}}

{{Term|colour morph}}

{{defn|See {{gli|morph}}.}}

{{Term|commissure}}

{{defn|Depending on usage, may refer to the junction of the {{gli|upper mandible|upper}} and {{gli|lower mandible|lower}} mandibles,{{Harvnb|Coues|1890|p=155}} or alternately, to the full-length apposition of the closed mandibles, from the corners of the mouth to the tip of the {{gli|beak}}.{{Harvnb|Campbell|Lack|1985|p=105}}}}

{{Term|contact call|content=contact call {{anchor|contact calls}} }}

{{defn|A type of {{gli|call}} used by birds for the purpose of letting others of their species know their location.{{Harvnb|Weaver|1981|p=34}}}}

{{Term|corpuscles of Herbst|content=corpuscles of Herbst {{anchor|corpuscle of Herbst|Herbst corpuscle|Herbst corpuscles}} }}

{{defn|Nerve-endings similar to the Pacinian corpuscle, found in the mucous membrane of the tongue, in pits on the beak and in other parts of the bodies of birds. They differ from Pacinian corpuscles in being smaller and more elongated, in having thinner and more closely placed capsules and in that the axis-cylinder in the central clear space is encircled by a continuous row of nuclei.{{cite book|last1=Klein|first1=Edward |title=Elements of Histology|url=https://archive.org/details/elementshistolo02kleigoog|place=Philadelphia|year=1785|publisher=Lea|page=[https://archive.org/details/elementshistolo02kleigoog/page/n140 124]}}}}

{{Term|coverts|content=coverts {{anchor|covert|covert feather|covert feathers|tectrices|tectrice|tectrix}} }}

{{Main|Covert feather}}

{{defn|Also, covert feathers; tectrices – singular: tectrix. A layer of non-flight feathers overlaying and protecting the {{gli|quills}} of flight feathers. At least one layer of covert feathers appear both above and beneath the {{gli|flight feathers}} of the wings as well as above and below the {{gli|rectrices}} of the tail.{{cite book|last1=Pierce|first1=R.M.|title=Dictionary of aviation|url=https://books.google.com/books?id=L84PAwAAQBAJ&pg=PA69|publisher=Рипол Классик|isbn=978-5-87745-565-8|pages=69–70|year=1911}} These feathers may vary widely in size. For example, the upper tail tectrices of peacocks—the male peafowl—rather than its rectrices, are what constitute its elaborate and colourful "train".{{Harvnb|Mobley, et al.|2008|p=295}} There are a number of types and subtypes of covert feathers—primary, secondary, greater, lesser, marginal, median, etc.—see broadly {{gli|wing coverts}} and {{gli|tail coverts}}.}}

{{Term|cranial kinesis|content=cranial kinesis {{anchor|prokinesis|amphikinesis|distal rhynchokinesis}} }}

{{defn|Also defined: prokinesis, amphikinesis and distal rhynchokinesis. Movement of the {{gli|upper mandible}} in relation to the front of the skull. There is very little of this movement in birds that feed primarily through grazing and thus do not need to open their bills very widely. This is in contrast to parrots, which use their bills to manipulate food and as a support when climbing trees. There are multiple types of cranial kinesis: prokinesis, where the bill moves only at the craniofacial hinge; amphikinesis, where the whole upper jaw is raised; and distal rhynchokinesis, where the bill flexes somewhere along the length of the bill, compared to just at the base.{{Harvnb|Elphick|2016|pp=22–23}}}}

File:Umbrella Cockatoo (Cacatua alba) -Free Flight Aviary -San Diego.jpg, also called the umbrella cockatoo from the shape of its {{gli|crest}}]]

{{Term|crest feather|content=crest feather {{anchor|crest|crests|crest feathers|recumbent crest|recursive crest|recumbent crests|recursive crests|quill feather|quill feathers}} }}

{{Main|Crest (feathers)}}

{{defn|Collectively, the/a crest. Long crest feathers are sometimes called quill feathers.{{Harvnb|Carnaby|2008|p=10}} Also defined: recumbent crests and recursive crests. A type of {{gli|semiplume}} feather with a long {{gli|rachis}} with {{gli|barbs}} on either side, that often presents as a prominent tuft on the {{gli|crown}} and (or through) the neck and upper {{gli|back}}.{{cite magazine|magazine=Bulletin of the British Ornithologists' Club|last=Tye|first=Hilary|volume=106|issue=3|title=The erectile crest and other head feathering in the genus Picathartes|page=91|date=December 1985|url=https://www.biodiversitylibrary.org/item/123887#page/499/mode/1up|access-date=2018-01-14|archive-date=2018-08-07|archive-url=https://web.archive.org/web/20180807203306/https://www.biodiversitylibrary.org/item/123887#page/499/mode/1up|url-status=live}} Birds with crests include Victoria crowned pigeons, northern lapwings, macaroni penguins and others, but the most recognizable are cockatoos and cockatiels, which can raise or lower their crests at will and use them to communicate with fellow members of their species, or as a form of defence to frighten away other species that approach too closely, making the bird appear larger when the crest is suddenly and unexpectedly raised.{{cite web|last=Highfill|first=Carol|title=Those Magnificent Cockatoo Crests|url=http://www.birdsnways.com/cockatoo/crests.htm|publisher=Cockatoo Heaven|access-date=March 23, 2017|archive-url=https://web.archive.org/web/20170301234333/http://www.birdsnways.com/cockatoo/crests.htm|archive-date=March 1, 2017|url-status=dead}} In some species the position of the crest is a threat signal that can be used to predict behaviour. In Steller's jays, for example, a raised crest indicates a likelihood of attack, and a lowered crest indicates a likelihood of retreat.{{Harvnb|Gill|1995|pp=318–319}} Crests can be recumbent or recursive, depending on the species. The recumbent crest, such as in white cockatoos, has feathers that are straight and lie down essentially flat on the head until fanned out.{{cite book|last=Moustaki|first=Nikki|title=Parrots for Dummies|year=2005|publisher=Wiley|location=Indianapolis, IN |isbn=978-0764583537|edition=1st}} The recursive crest, such as in sulphur-crested cockatoos and Major Mitchell's cockatoos, is noticeable even when its feathers are not fanned out because they curve upward at the tips even when lying flat, and when standing up, often bend slightly forward toward the front of the head. Some birds, like galahs (also known as the rose-breasted cockatoo), have modified crests that have both recumbent and recursive features.}}

File:Grey Catbird.jpg, with its distinctly coloured {{gli|crissum}} on display]]

{{Term|crissum|content=crissum}}

{{defn|The feathered area between the {{gli|vent}} and the {{gli|tail}}. Also, the collective name for the {{gli|undertail coverts}}.{{Harvnb|Pettingill|1985|p=21}} The crissal thrasher derives its name from the term, having distinctive colouring in the region, in contrast with the balance of its {{gli|plumage}}. Other birds having distinctive crissum colouration include Le Conte's thrashers and grey catbirds.{{cite book|last=Burns|first=Jim|title=Jim Burns' Arizona Birds: From the Backyard to the Backwoods|url=https://books.google.com/books?id=fFUNsToqnFMC&pg=PA166|year=2008|publisher=University of Arizona Press|isbn=978-0-8165-2644-4|page=166}}}}

{{Term|crop|content=crop {{anchor|crops}} }}

{{Main|Crop (anatomy)#Birds}}

{{defn|An expanded, muscular pouch near the gullet or throat found in some but not all birds. It is a part of the digestive tract, essentially an enlarged part of the esophagus, used for the storage of food prior to digestion. As with most other organisms that have a crop, birds use it to temporarily store food. In adult doves and pigeons, the crop can produce {{gli|crop milk}} to feed newly-hatched chicks.{{cite web|title=The Alimentary Canal in Birds|url=http://www.earthlife.net/birds/digestion.html|last1=Ramel|first1=Gordon|date=September 29, 2008|access-date=January 16, 2017|archive-url=https://web.archive.org/web/20170201223304/http://www.earthlife.net/birds/digestion.html|archive-date=February 1, 2017|url-status=dead}}}}

File:Rosaflamingo-Küken - Fuetterung mit Kropfmilch.jpg chick being fed {{gli|crop milk}}]]

{{Term|crop milk}}

{{Main|Crop milk}}

{{defn|A secretion from the lining of the {{gli|crop}} of parent birds that is regurgitated to young birds. It is found among all pigeons and doves where it is referred to as {{gli|pigeon milk}}. An analogue to crop milk is also secreted from the esophagus of flamingos and some penguins.{{cite book |last=Levi |first=Wendell |title= The Pigeon|year= 1977|publisher= Levi Publishing Co, Inc|location= Sumter, S.C.|isbn=978-0-85390-013-9 }}{{cite magazine|last=Silver|first=Rae|title=Prolactin and Parenting in the Pigeon Family|magazine=The Journal of Experimental Zoology|volume=232|pages=617–625|year=1984|url=http://www.columbiauniversity.org/cu/psychology/silver/publications/035Silver%201984.PDF|doi=10.1002/jez.1402320330|pmid=6394702|issue= 3|url-status=bot: unknown|archive-url=https://web.archive.org/web/20160913135843/http://www.columbiauniversity.org/cu/psychology/silver/publications/035Silver%201984.PDF|archive-date=September 13, 2016}}{{cite magazine|last1=Eraud|first1=C.|last2=Dorie|first2=A.|last3=Jacquet|first3=A.|last4=Faivre|first4=B.|year=2008| title= The crop milk: a potential new route for carotenoid-mediated parental effects| magazine=Journal of Avian Biology| volume=39| pages=247–251| doi=10.1111/j.0908-8857.2008.04053.x| issue= 2}} Crop milk bears little physical resemblance to mammalian milk, the former being a semi-solid substance somewhat like pale yellow cottage cheese. It is extremely high in protein and fat, containing higher levels than cow or human milkEhrlich, Paul R.; Dobkin, David S. and Wheye, Darryl (1988) [http://www.stanford.edu/group/stanfordbirds/text/essays/Bird_Milk.html Bird Milk] {{Webarchive|url=https://web.archive.org/web/20121015052523/http://www.stanford.edu/group/stanfordbirds/text/essays/Bird_Milk.html |date=2012-10-15 }}. stanford.edu and has been shown to also contain antioxidants and immune-enhancing factors.{{cite web|url=http://www.australiangeographic.com.au/journal/birds-produce-milk-similar-to-mammals.htm|title=Mysteries of pigeon milk explained|access-date=August 17, 2017|url-status=dead|archive-url=https://web.archive.org/web/20130814213943/http://www.australiangeographic.com.au/journal/birds-produce-milk-similar-to-mammals.htm|last=Phillips|first=Campbelll|date=September 22, 2011|archive-date=August 14, 2013|publisher=Australian Geographic}}}}

{{Term|crown|content=crown {{anchor|crowns|occiput|hindhead}} }}

{{defn|Also defined: occiput / hindhead. The portion of a bird's head found between the {{gli|forehead}}—demarcated by an imaginary line drawn from the anterior corners of the eyes—and through the "remainder of the upper part of the head", to the {{gli|superciliary line}}. The occiput or hindhead, is the posterior part of the crown.{{Harvnb|Pettingill|1985|p=10}}}}

{{Term|cryptic plumage|content=cryptic plumage {{anchor|cryptic plumages|cryptic|phaneric plumage|phaneric plumages|phaneric}} }}

{{defn|Also defined: phaneric plumage. Plumage of a bird that is camouflaging. For example, the white winter plumage of ptarmigans is cryptic as it serves to conceal it in snowy environments.{{Harvnb|Gill|1995|p=106}} The opposite, "advertising" plumage, is termed "phaneric", such as male birds in colourful {{gli|nuptial plumage}} for sexual display, making them stand out to a high degree.{{cite book|last=Ryser|first=Fred A.|title=Birds of the Great Basin: A Natural History|url=https://books.google.com/books?id=bxpXq_hMxfAC&pg=PA22|year=1985|publisher=University of Nevada Press|isbn=978-0-87417-080-1|page=22}}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }}}}

{{Term|culmen}}

{{Main|Beak#Culmen}}

{{defn|The dorsal ridge of the {{gli|upper mandible}}.{{Harvnb|Campbell|Lack|1985|p=127}} Likened by ornithologist Elliott Coues to the ridge line of a roof, it is the "highest middle lengthwise line of the bill" and runs from the point where the upper mandible emerges from the forehead's feathers to its tip.{{Harvnb|Coues|1890|p=152}} The {{gli|bill}}'s length along the culmen is one of the regular measurements made during bird ringing{{cite book |title=Identification Guide to North America Passerines |first1=Peter|last1=Pyle|first2=Steve N. G.|last2=Howell|first3=Robert P.|last3=Yunick|first4=David F. |last4=DeSante|publisher=Slate Creek Press|location=Bolinas, CA|year=1987|isbn=978-0-9618940-0-9|pages=6–7}} and is particularly useful in feeding studies.{{cite magazine|title=What Do Different Bill Measures Measure and What Is the Best Method to Use in Granivorous Birds?|url=http://www.bcn.cat/museuciencies_fitxers/imatges/FitxerContingut1987.pdf|first1=A.|last1=Borras|first2=J.|last2=Pascual|first3=J. C.|last3=Senar|magazine=Journal of Field Ornithology|volume=71|issue=4|date=Autumn 2000|pages=606–611|jstor=4514529|doi=10.1648/0273-8570-71.4.606|access-date=2017-01-17|archive-date=2016-03-04|archive-url=https://web.archive.org/web/20160304080233/http://www.bcn.cat/museuciencies_fitxers/imatges/FitxerContingut1987.pdf|url-status=live}} The shape or colour of the culmen can also help with the identification of birds in the field. For example, the culmen of the parrot crossbill is strongly decurved, while that of the very similar appearing red crossbill is more moderately curved.{{cite book|title=Collins Bird Guide: The Most Complete Field Guide to the Birds of Britain and Europe |first1=Killian|last1=Mullarney|first2=Lars|last2=Svensson |first3=Dan|last3=Zetterström|first4=Peter J.|last4=Grant|year=1999|publisher=Harper Collins |location=London|isbn=978-0-00-711332-3|page=357}}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|definitive plumage|content=definitive plumage {{anchor|definitive plumages|adult plumage|adult plumages}} }}

{{defn|Adult plumage sufficiently developed and fixed following the juvenile years such that it no longer changes significantly in appearance with age.}}

{{Term|diastataxis}}

{{defn|The state of lacking a fifth {{gli|secondary feather}} on each wing, which occurs in birds in more than 40 non-passerine families. In these birds, the fifth set of secondary covert feathers does not cover any {{gli|remex}}. Loons, grebes, pelicans, hawks and eagles, cranes, sandpipers, gulls, parrots and owls are among the families missing this feather.{{Harvnb|Campbell|Lack|1985|p=656}}}}

{{Term|dietary classification terms (-vores)|content=dietary classification terms (-vores) {{anchor|insectivore|insectivores|insectivorous|carnivore|carnivores|carnivorous|faunivore|faunivores|faunivorous|folivore|folivores|folivorous|crustacivores|crustacivores|crustacivorous|nectarivore|nectarivores|nectarivorous|frugivore|frugivores|frugivorous|granivore|granivores|granivorous|omnivore|omnivores|omnivorous|general feeders|piscivore|piscivores|piscivorous|florivore|florivores|florivorous|folivore|folivores|folivorous|sanguinivore|sanguinivores|sanguinivorous|saprovore|saprovores|saprovorous|herbivore|herbivores|herbivorous|detritivore|detritivores|detritivorous}} }}

{{defn|Birds may be classified by terms related to the types of foods they forage for and eat.{{Harvnb|Carnaby|2008|p=334}} The -vore suffix is derived from the Latin vorare, meaning 'to devour'. Equivalent adjectives can be formed through use of the suffix -vorous.{{cite book|last=Molles|first=Manuel C. Jr. |title=Ecology: Concepts and Applications|url=https://archive.org/details/ecologyconceptsa0000moll_j9m2|url-access=registration|publisher=McGraw-Hill|edition=International |year=1999|location=Dubuque|page=[https://archive.org/details/ecologyconceptsa0000moll_j9m2/page/510 510]|isbn=978-0-07-042716-7}} For example, granivore (n.) / granivorous (adj.). Generally, classification terms are used based on predominance of food source and/or specialization. There can be much cross-over and mixing between classifications. For example, insectivores and piscivores may at times be described more broadly as types of carnivores, and hummingbirds, though they do eat insects, are often described as nectarivores, rather than insectivores, as nectar is a specialized and predominant food foraging source for that bird family.{{cite book|last1=Hosey|first1=Geoff |last2=Melfi|first2=Vicky |author3=Sheila Pankhurst|title=Zoo Animals: Behaviour, Management, and Welfare|url=https://books.google.com/books?id=Ua2cAQAAQBAJ&pg=PA419|year=2013|publisher=OUP Oxford|isbn=978-0-19-969352-8|page=419}} The feeding strategies of birds is intimately tied to their physiology and evolutionary development. For example, {{gli|beak}} shape and structure such as the makeup of the {{gli|tomia}}, the presence (or not) of a {{gli|bill tip organ}} and myriad other adaptations are tied to a species' feeding strategies.{{cite book|last=Scanes|first=Colin G.|title=Sturkie's Avian Physiology|url=https://books.google.com/books?id=wgN0AwAAQBAJ&pg=PA61|year=2014|publisher=Elsevier Science|isbn=978-0-12-407243-5|page=61}} Feeding habits also correlate with aspects of brain development and size. For example, the spatial memory of birds that store food in various locations has been shown to be highly developed and contributes towards success at that feeding tactic.{{cite book|last1=Adams|first1=Rick A.|last2=Pedersen|first2=Scott C.|title=Ontogeny, Functional Ecology, and Evolution of Bats|url=https://books.google.com/books?id=W61Cjl6xJvsC&pg=PA124|year=2000|publisher=Cambridge University Press|isbn=978-1-139-42949-8|page=124}}}}

:

{{Term|dimorphism}}

{{defn|See {{gli|sexual dimorphism}}.}}

{{Term|diving|content=diving {{anchor|diver|surface diving|plunge diving|surface diver|plunge diver|surface divers|plunge divers|surface-diver|plunge-diver|surface-divers|plunge-divers}} }}

{{defn|Also defined: surface diving; plunge diving. Some birds dive into the water for food. Two diving strategies are differentiated: surface diving birds dive from the surface of the water and swim actively underwater; and plunge diving birds dive from the air into the water. Plunge diving birds may use the momentum from the plunge to propel themselves underwater, whereas others may swim actively.{{Harvnb|Elphick|2016|pp=110–111}}}}

File:Eider.a.duvet4.jpg sits on her nest, surrounded by {{gli|down feathers}}]]

{{Term|down|content=down {{anchor|down feather|down feathers|downfeather|downfeathers|plumulaceous feather|plumulaceous feathers|plumulaceous}} }}

{{Main|Down feather}}

{{defn|Also, down feathers or plumulaceous feathers. The down of birds—their plumulaceous feathers, as opposed to {{gli|pennaceous feathers}}—are a layer of fine, silky feathers found under the tougher exterior feathers, that are often used by humans as a thermal insulator and padding in goods such as jackets, bedding, pillows and sleeping bags. Considered to be the "simplest" of all feather types,{{cite book |title=The Integumen: A Textbook of Skin Biology |first=Richard Ian Campbell |last=Spearman |page=[https://archive.org/details/integumenttextbo00spea/page/97 97] |year=1973 |isbn=978-0-521-20048-6 |publisher=Cambridge University Press |url=https://archive.org/details/integumenttextbo00spea/page/97 }} down feathers have a short or vestigial rachis (shaft), few barbs and barbules that lack hooks,{{Harvnb|del Hoyo|Elliott|Sargatal|1992|p=39}} and (unlike {{gli|contour feathers}}) grow from both the {{gli|pterylae}} and the {{gli|apteria}}. Very young birds are often only clad in down. The loose structure of down feathers traps air, which helps to insulate birds against heat loss and contributes to the buoyancy of waterbirds. Species that experience annual temperature fluctuations typically have more down feathers following their autumn moult.{{Harvnb|Scott|2010|p=31}} There are three types of down: {{gli|natal down}}, {{gli|body down}} and {{gli|powder down}}.{{Harvnb|Elphick|2016|pp=75–77}}}}

{{Term|drumming}}

{{defn|A form of non-vocal communication engaged in by members of the woodpecker family. It involves the {{gli|beak}} striking a hard surface multiple times per second. The drumming pattern, the number of beats per roll and the gap between rolls is specific to each species. Drumming is usually associated with territorial behaviour, with male birds drumming more frequently than females.{{cite book |title=Woodpeckers of the World: A Photographic Guide |last=Gorman|first=Gerard |year=2014|publisher=Firefly Books|isbn=978-1-77085-309-6|page=28}} Drumming may also refer to the sounds produced by the specialised outer tail-feathers of snipe in the course of their courtship display flights.{{cite web |url=http://www.birdsinbackyards.net/species/Gallinago-hardwickii |title=Latham's Snipe - Did you know? |work=Birds in Backyards |publisher=Birdlife Australia |access-date=January 25, 2017 |archive-date=January 25, 2017 |archive-url=https://web.archive.org/web/20170125175936/http://www.birdsinbackyards.net/species/Gallinago-hardwickii |url-status=dead }}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

File:Comparison of eggs by Zureks.jpg

{{Glossary}}

{{Term|ear-coverts|content=ear-coverts {{anchor|ear-covert|ear covert|ear coverts|ear covert feathers|ear covert feather}} }}

{{defn|Small {{gli|covert}} feathers located behind a bird's eye, in one to four rows, which cover the ear opening (bird ears have no external features) and may aid in the acuity of bird hearing.{{cite book|last1=Farner|first1=Donald S.|last2=King|first2=James R.|title=Avian Biology|url=https://books.google.com/books?id=CC3LBAAAQBAJ&pg=PA13|year=2013|publisher=Elsevier|isbn=978-1-4832-6942-9|page=13}}}}

{{Term|egg|content=egg {{anchor|eggs|eggshell|eggshells|egg shell|egg shells|albumen|egg white|egg whites|glair|glaire|yolk|yolks|chalaza|chalazae|egg cell|egg cells}} }}

{{Main|Egg}}

{{defn|Also defined: eggshell; yolk; albumen; chalaza. The organic vessel containing the zygote, in which birds develop until hatching. Eggs are usually oval in shape, and have a base white colour from the predominant calcium carbonate makeup of the outer shell, called the eggshell, though {{gli|passerine}} birds especially may have eggs of other colours,{{cite book|last=Pycraft|first=W.P.|title=Scientific American: Supplement: The Curious Phenomena of Eggshell Pigmentation|url=https://books.google.com/books?id=lek5AQAAMAAJ&pg=PA376|year=1908|publisher=Munn and Company|page=376}} such as through deposition of biliverdin and its zinc chelate, which give a green or blue ground colour, and protoporphyrin which produces reds and browns.{{cite book|last1=Hill|first1=Geoffrey Edward|last2=McGraw|first2=Kevin J. |title=Bird Coloration: Mechanisms and measurements|url=https://books.google.com/books?id=WnJ8cSoXRMIC&pg=PA368|year=2006|publisher=Harvard University Press|isbn=978-0-674-01893-8|page=368}} A viable bird egg (as opposed to a non-viable egg: see {{gli|addled eggs}}) consists of a number of structures. The eggshell is 95–97% calcium carbonate crystals, at least in chickens, stabilized by a protein matrix,{{cite magazine|last1=Arias|first1=J. L.|last2=Fernandez|first2=M. S.|title=Role of extracellular matrix molecules in shell formation and structure|magazine=World's Poultry Science Journal |volume=57|issue= 4|pages=349–357|year=2001|doi=10.1079/WPS20010024|s2cid=86152776}}{{cite magazine|year=2005|volume=7|issue= 2|pages=67–71|last1=Hunton |first1=P.|title=Research on eggshell structure and quality: an historical overview|magazine=Revista Brasileira de Ciência Avícola|doi=10.1590/S1516-635X2005000200001|doi-access=free}}{{cite magazine|last1=Nys|first1=Yves|last2=Gautron|first2=Joël|last3=Garcia-Ruiz|first3=Juan M.|last4=Hincke|first4=Maxwell T.|title=Avian eggshell mineralization: biochemical and functional characterization of matrix proteins|magazine=Comptes Rendus Palevol|volume=3|issue= 6–7|pages=549–562|year=2004|doi= 10.1016/j.crpv.2004.08.002}} without which the crystalline structure would be too brittle to keep its form; the organic matrix is thought to have a role in deposition of calcium during the mineralization process.{{cite book|last1=Romanoff|first1=Alexis L.|last2=Romanoff|first2=Anastasia J.|year=1949|title=The Avian Egg|location=New York|publisher=Wiley|oclc=191965542}}{{cite book|last1=Burley|first1=R.W.|last2=Vadehra|first2=Dharam V.|year=1989|title=The Avian Egg: Chemistry and Biology|location=New York|publisher=Wiley|isbn=978-0-471-84995-7}}{{cite magazine|last1=Lavelin|first1=I., N.|last2=Meiri|first2=M. Pines|year=2000|title=New insight in eggshell formation|magazine=Poultry Science|volume=79|issue= 7|pages=1014–1017|doi=10.1093/ps/79.7.1014|pmid=10901204|doi-access=free}} The structure and composition of the avian eggshell serves to protect the egg against damage and microbial contamination, prevention of desiccation, regulation of gas and water exchange for the growing embryo and provides calcium for embryogenesis. Inside the eggshell are two shell membranes (inner and outer), and at the center is a yolk—a spherical structure, usually some shade of yellow, to which the fertilized gamete attaches and which the embryonic bird uses as sustenance as it grows. The yolk is suspended in the albumen (also called egg white or glair / glaire) by one or two spiral bands of tissue called the chalazae.{{cite book|last=Alderton|first=David|title=The Complete Guide to Bird Care|url=https://archive.org/details/completeguidetob00davi|url-access=registration|year=1998|publisher=Howell Book House|isbn=978-0-87605-038-5}} The albumen protects the yolk and provides additional nutrition for the embryo's growth,{{cite book|last=Harrison|first=John |title=Backgarden Chickens and Other Poultry|url=https://books.google.com/books?id=q4DABAAAQBAJ&pg=PT125|year=2011|publisher=Little, Brown Book Group|isbn=978-0-7160-2276-3|page=125}} though it is made up of approximately 90% water in most birds.{{cite book|last=Damerow|first=Gail |author-link=Gail Damerow |title=Hatching & Brooding Your Own Chicks: Chickens, Turkeys, Ducks, Geese, Guinea Fowl|url=https://books.google.com/books?id=gvq9maYXTw8C&pg=PA142|year=2013|publisher=Storey Publishing|isbn=978-1-60342-878-1|page=142}} Prior to fertilization, the yolk is a single cell ovum or egg cell; one of the few single cells that can be seen by the naked eye.{{cite book|last=Patten|first=Bradley M.|title=Early Embryology of the Chick|url=https://books.google.com/books?id=W3i643aSE_MC&pg=PA17|year=2008|publisher=Wildside Press LLC|isbn=978-1-4344-7385-1|page=17}}}}

{{Term|egg binding|content=egg binding {{anchor|egg bindings}} }}

{{Main|Egg binding}}

{{defn|An egg that while traversing the reproductive tract during the process of being laid, becomes stuck near to the opening of the {{gli|cloaca}} or further inside the oviduct.{{Cite episode|series=Dr. K's Exotic Animal ER|title=Sumo Dragon|series-link=Dr. K's Exotic Animal ER|network=Nat Geo Wild|date=May 21, 2016|minutes=26|season=03 E01}} The condition may be caused by obesity, nutritional imbalances such as calcium deficiency, environmental stress such as temperature changes, or malformed eggs.{{cite magazine|last1=Stout|first1=Jane D.|title=Common emergencies in pet birds|magazine=The Veterinary Clinics of North America. Exotic Animal Practice|date=May 2016|volume=19|issue= 2|pages=513–41|doi=10.1016/j.cvex.2016.01.002|pmid=26948267}} }}

{{Term|egg incubation|content=egg incubation {{anchor|egg incubating|incubation|incubating}} }}

{{Main|Egg incubation}}

{{defn|Also, brooding. The general care of unhatched eggs by parent birds (more often by females but by birds of both sexes), especially by temperature regulation through sitting on them, crouching or squatting over them, covering them with their wings, providing shade, wetting eggs and related behaviours. The target temperature of most species is {{convert|37|C}} to {{convert|38|C}}. In monogamous species incubation duties are often shared, whereas in polygamous species one parent is wholly responsible for incubation. Warmth from parents passes to the eggs through {{gli|brood patches}}—areas of bare skin on the abdomen or breast of the incubating birds. Incubation can be an energetically demanding process; adult albatrosses, for instance, lose as much as {{convert|83|g}} of body weight per day of incubation.{{cite book|last=Barrows|first=Edward M.|title=Animal Behavior Desk Reference: A Dictionary of Animal Behavior, Ecology, and Evolution, Second Edition|url=https://archive.org/details/animalbehaviorde0000barr|url-access=registration|year=2000|publisher=CRC Press|isbn=978-0-8493-2005-7|page=[https://archive.org/details/animalbehaviorde0000barr/page/79 79]}}{{Harvnb|Gill|1995|p=459}}{{cite book|last1=Warham|first1=J|year=1990|title=The Petrels: Their Ecology and Breeding Systems|location=London|publisher=Academic Press|isbn=978-0-12-735420-0}}}}

File:Poicephalus senegalus -egg tooth -two weeks-21July07.JPG chick at about two weeks after hatching. The {{gli|egg tooth}} is near the tip of its beak on the {{gli|upper mandible}}.]]

{{Term|egg tooth|content=egg tooth {{anchor|egg teeth|eggtooth|eggteeth}} }}

{{Main|Beak#Egg tooth}}

{{defn|A small, sharp, calcified projection on the beak that full-term chicks of most bird species have, which they use to chip their way out of their egg.{{Harvnb|Campbell|Lack|1985|p=178}} This white spike is located near the tip of the {{gli|upper mandible}} in most species (e.g., gulls);{{cite magazine |magazine=The Wilson Bulletin |first=Joseph R. Jr. |last=Jehl |volume=80 |issue=3 |pages=328–9 |title=The Egg Tooth of Some Charadriiform Birds |url=https://sora.unm.edu/sites/default/files/journals/wilson/v080n03/p0328-p0330.pdf |date=September 1968 |access-date=2020-10-19 |archive-date=2020-10-22 |archive-url=https://web.archive.org/web/20201022202340/https://sora.unm.edu/sites/default/files/journals/wilson/v080n03/p0328-p0330.pdf |url-status=live }} near the tip of the {{gli|lower mandible}} instead in a minority of others, such as northern lapwings; with a few species, such as Eurasian whimbrels, black-winged stilts and semipalmated sandpipers, having one on each mandible.{{cite book |title=New Generation Guide to the Birds of Britain and Europe |first1=Christopher M. |last1=Perrins |first2=David |last2=Attenborough |first3=Norman |last3=Arlott |publisher=University of Texas Press |location=Austin, TX |year=1987 |isbn=978-0-292-75532-1 |page=205}} Despite its name, the projection is not an actual tooth (as the similarly-named projections of some reptiles are); instead, it is part of the integumentary system, as are claws and {{gli|scales}}.{{cite magazine |magazine=The Wilson Bulletin |first=George A. Jr. |last=Clark |volume=73 |issue=3 |pages=268–278 |title=Occurrence and Timing of Egg Teeth in Birds |url=http://sora.unm.edu/sites/default/files/journals/wilson/v073n03/p0268-p0278.pdf |date=September 1961 |access-date=2017-01-20 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304211935/http://sora.unm.edu/sites/default/files/journals/wilson/v073n03/p0268-p0278.pdf |url-status=live }} The hatching chick first uses its egg tooth to break the membrane around an air chamber at the wide end of the egg. Then it pecks at the eggshell while turning slowly within the egg, eventually (over a period of hours or days) creating a series of small circular fractures in the shell.{{Harvnb|Gill|1995|p=427}} Once it has breached the egg's surface, the chick continues to chip at it until it has made a large hole. The weakened egg eventually shatters under the pressure of the bird's movements.{{Harvnb|Gill|1995|p=428}} The egg tooth is so critical to a successful escape from the egg that chicks of most species will perish unhatched if they fail to develop one.}}

{{Term|emargination|content=emargination {{anchor|emarginations}} }}

{{Main|Flight feather#Emargination}}

{{defn|A pronounced narrowing at some variable distance along the feather edges at the outermost {{gli|primaries}} of large soaring birds, particularly raptors. Whether these narrowings are called {{gli|notches}} or emarginations' depends on the degree of their slope. An emargination is a gradual change, and can be found on either side of the feather. A notch is an abrupt change, and is only found on the wider trailing edge of the remige. The presence of notches and emarginations creates gaps at the wingtip; air is forced through these gaps, increasing the generation of lift.{{Harvnb|Trail|2001|p=6}}}}

{{Term|eye-ring|content=eye-ring {{anchor|eye-rings|eye ring|eye rings|eyering|eyerings|orbital ring|orbital ring|orbital rings|orbital-ring|orbital-rings|eye arc|eye-arc|eye arcs|eye-arcs}} }}

{{Main|Eye-ring}}

{{defn|Also defined: orbital ring. A visible ring of feathers around a bird's eye; the eye-ring is often paler than the surrounding feathers. By contrast, an orbital ring is bare skin ringing the eye. In some species, such as little ringed plover, the orbital ring may be quite conspicuous.}}

{{Term|eyestripe|content=eyestripe {{anchor|eye stripe|eye-stripe|eyeline|eye line|eye-line}} }}

{{defn|Also, eye line / eyeline. A visible stripe on the feathers of a bird's head, often darker than the surrounding feathers, running through the eye region. Compare {{gli|supercilium}}.}}

{{Gallery

|title=Eye features

|width=150

|height=180

|align=center

|File:Blue-headed Vireo-cropped.jpeg|Blue-headed vireo, with a conspicuous {{gli|eye-ring}}

|File:Little ringed plover-chick-cropped.jpeg|Little ringed plover chick, with a conspicuous {{gli|orbital ring}}

|File:White-eared Sibia-Taiwan-cropped-eyestripe.jpeg|White-eared sibia, with a conspicuous {{gli|eyestripe}}

|File:Saxicola rubetra -Belgium -male-8-cropped.jpeg|Whinchat, with a conspicuous {{gli|supercilium}} (eyebrow)

}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

File:Types de plumes. - Larousse pour tous, -1907-1910-.jpg

{{Glossary}}

{{Term|term=feather|content=feather {{anchor|feathers}} }}

{{main|Feather}}

{{defn|Epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates,{{cite magazine|last1=Prum|first1=Richard O.|author-link=Richard Prum|last2=Brush|first2=A.H.|year=2002|title=The evolutionary origin and diversification of feathers|magazine=The Quarterly Review of Biology|volume=77|issue=3|url=http://www.yale.edu/eeb/prum/pdf/Prum_n_Brush_2002.pdf|pages=261–295|doi=10.1086/341993|pmid=12365352|access-date=2017-01-17|archive-date=2011-06-29|archive-url=https://web.archive.org/web/20110629175850/http://www.yale.edu/eeb/prum/pdf/Prum_n_Brush_2002.pdf|url-status=live}}{{cite magazine|doi=10.1038/scientificamerican0303-84|date=March 2003|last1=Prum|first1=Richard O.|last2=Brush|first2=A.H.|title=Which Came First, the Feather or the Bird?|magazine=Scientific American|volume=288|issue=3|pages=84–93|doi-broken-date=1 November 2024 |url=http://www.yale.edu/eeb/prum/pdf/Prum_n_Brush_2003.pdf|pmid=12616863|bibcode=2003SciAm.288c..84P|access-date=2017-01-17|archive-date=2011-06-29|archive-url=https://web.archive.org/web/20110629175910/http://www.yale.edu/eeb/prum/pdf/Prum_n_Brush_2003.pdf|url-status=live}} and, indeed, a premier example of a complex evolutionary novelty.{{cite magazine|doi=10.1002/(SICI)1097-010X(19991215)285:4<291::AID-JEZ1>3.0.CO;2-9|year=1999|last1=Prum|first1=Richard O.|title=Development and Evolutionary Origin of Feathers|magazine=Journal of Experimental Zoology|volume=285|issue=4|pages=291–306|pmid=10578107|url=http://prumlab.yale.edu/sites/default/files/prum_1999_mde_development.pdf|access-date=2017-04-12|archive-date=2018-05-02|archive-url=https://web.archive.org/web/20180502132252/https://prumlab.yale.edu/sites/default/files/prum_1999_mde_development.pdf|url-status=live}} Feathers are among the characteristics that distinguish the extant birds from other living groups.{{cite magazine |last=Li |first=Quanguo |title=Reconstruction of Microraptor and the Evolution of Iridescent Plumage |magazine=Science |volume=335 |issue= 6073 |pages=1215–1219 |date=March 9, 2012 |doi=10.1126/science.1213780 |pmid=22403389 |bibcode=2012Sci...335.1215L|s2cid=206537426}} Although feathers cover most parts of the body of birds, they arise only from certain well-defined {{gli|pterylosis|tracts}} on the skin. They aid in flight, thermal insulation and waterproofing, with their colouration helping in communication and protection.{{Harvnb|Pettingill|1985|p=29}} Although there are many subdivisions of feathers, at the broadest levels, feathers are either classified as i) {{gli|vaned feathers}}, which cover the exterior of the body and include {{gli|pennaceous feathers}}, or ii) {{gli|down feathers}}, which grow underneath the vaned feathers. A third rarer type of feather, the {{gli|filoplume}}, is hairlike and (if present in a bird; they are entirely absent in ratites{{Harvnb|Chandler|1916|p=285}}) grows alongside the contour feathers. A typical vaned feather features a main shaft called the {{gli|quill}} with an upper section called the {{gli|rachis}}. Fused to the rachis are a series of branches, or {{gli|barbs}}; the barbs in turn have {{gli|barbules}} branching off them, and they in turn branch yet again with a series of growths called {{gli|barbicels}}, some of which have minute hooks called {{gli|hooklets}} for cross-attachment. Down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular {{gli|calamus}} which inserts into a follicle in the skin. The basal part of the calamus is without vanes. This part is embedded within the skin follicle and has an opening at the base ({{gli|proximal umbilicus}}) and a small opening on the side ({{gli|distal umbilicus}}).{{Cite book|title=A color atlas of avian anatomy|last= McLelland| first=J.|publisher=W.B. Saunders Co.|year=1991|isbn=978-0-7216-3536-1}}}}

{{Term|feather pecking|content=feather pecking {{anchor|feather-pecking}} }}

{{main|Feather pecking}}

{{defn|A behavioural problem in which one bird repeatedly pecks at the feathers of another, that occurs most frequently amongst domestic hens reared for egg production,{{cite magazine|last1=Huber-Eicher|first1=B.|last2=Sebo|first2=F.|magazine=Applied Animal Behaviour Science|title=The prevalence of feather pecking and development in commercial flocks of laying hens|issue= 3|volume=74|pages=223–231|year=2001|doi=10.1016/S0168-1591(01)00173-3}}{{cite magazine|last1=Sherwin|first1=C.M.|last2=Richards|first2=G.J|last3=Nicol|first3=C.J.|magazine=British Poultry Science|title=A comparison of the welfare of layer hens in four housing systems in the UK|volume=51|issue= 4|year=2010|pages=488–499|doi=10.1080/00071668.2010.502518|pmid=20924842|s2cid=8968010}} although it is seen in other poultry such as pheasants,{{cite magazine|last1=Butler|first1=D.A.|last2=Davis|first2=C.|magazine=Veterinary Record|title=Effects of plastic bits on the condition and behaviour of captive-reared pheasants|volume=166 |pages=398–401|issue= 13|year=2010|doi=10.1136/vr.b4804|pmid=20348469|s2cid=7549266}} turkeys,{{cite book|last1=Sherwin|first1=C.M.|editor-last1=Pond|editor-first1=Wilson G.|editor-last2=Bell|editor-first2=Alan W.|publisher=Marcel Dekker|title=The Encyclopaedia of Animal Science|chapter=Turkeys: Behavior, Management and Well-Being|year=2010|pages=847–849}} ducks{{cite magazine|last1=Gustafson|first1=Leslie A.|last2=Cheng|first2=Heng-Wei |last3=Garner|first3= Joseph P.|last4=Pajorc|first4=Edmond A.|last5=Mench|first5=Joy A. |magazine=Applied Animal Behaviour Science|title= Effects of bill-trimming Muscovy ducks on behavior, body weight gain, and bill morphopathology|volume=103|issue=1–2 |year=2007|pages=59–74|doi=10.1016/j.applanim.2006.04.003}} and sometimes in farmed ostriches.{{cite magazine|last1=Reischl|first1=E.|last2=Sambraus|first2=H.H.|year=2003|title=Feather-pecking of African ostriches in Israel|magazine=Tierarztliche Umschau|volume=58|issue= 7|pages=364–369|doi=}} Two levels of severity are recognised: "gentle" and "severe".{{cite magazine|last1=McAdie|first1= T.M.|last2=Keeling|first2=L.J.|magazine=Applied Animal Behaviour Science|title=The social transmission of feather pecking in laying hens: effects of environment and age|issue= 2|volume=75|pages=147–159|year=2002|doi=10.1016/S0168-1591(01)00182-4}}}}

File:Ara militaris.jpg on the left is displaying signs of {{gli|feather-plucking}}.]]

{{Term|feather-plucking|content=feather-plucking {{anchor|feather plucking|feather-picking|feather picking|pterotillomania|feather damaging behaviour}} }}

{{main|Feather-plucking}}

{{defn|Also feather-picking, feather damaging behaviour or pterotillomania.{{cite magazine|last1=Lumeij|first1=Johannes T.|last2=Hommers|first2=Caroline J.|year=2008|title=Foraging 'enrichment' as treatment for Pterotillomania|magazine=Applied Animal Behaviour Science|volume=111|issue=1–2|pages=85–94|url=http://img2.tapuz.co.il/forums/1_148363975.pdf|doi=10.1016/j.applanim.2007.05.015|access-date=2020-12-20|archive-date=2015-11-23|archive-url=https://web.archive.org/web/20151123180457/http://img2.tapuz.co.il/forums/1_148363975.pdf|url-status=dead}} A maladaptive, behavioural disorder commonly seen in captive birds which chew, bite or pluck their own feathers with their beak, resulting in damage to the feathers and occasionally the skin.{{cite web|url=http://www.beautyofbirds.com/featherplucking.html|title=Feather Plucking in Pet Birds|website=Beauty of Birds|year=2011|access-date=December 21, 2020|archive-date=November 2, 2019|archive-url=https://web.archive.org/web/20191102211331/https://www.beautyofbirds.com/featherplucking.html|url-status=live}}{{cite web|url=https://www.purdue.edu/uns/html4ever/2005/051221.Garner.parrots.html|title=Parrots' behaviors mirror human mental disorders|date=December 21, 2005|access-date=December 21, 2020|last=Steeves|first=Susan A.|publisher=Purdue University|archive-date=April 10, 2021|archive-url=https://web.archive.org/web/20210410211405/https://www.purdue.edu/uns/html4ever/2005/051221.Garner.parrots.html|url-status=live}} It is especially common among Psittaciformes, with an estimated 10% of captive parrots exhibiting the disorder.{{cite magazine|last1=van Zeeland|first1=Yvonne R.A.|last2=Spruit|first2=Berry M.|last3=Rodenburg|first3=T. Bass|title=Feather damaging behaviour in parrots: A review with consideration of comparative aspects|magazine=Applied Animal Behaviour Science|volume=121|issue=2|pages=75–95|doi=10.1016/j.applanim.2009.09.006|date=November 2009|url=https://www.sciencedirect.com/science/article/abs/pii/S0168159109002561|display-authors=etal|access-date=2020-12-21|archive-date=2023-05-28|archive-url=https://web.archive.org/web/20230528143717/https://www.sciencedirect.com/science/article/abs/pii/S0168159109002561|url-status=live}} The chief areas of the body that are pecked or plucked are the more accessible regions such as the neck, chest, {{gli|flank}}, inner thigh and ventral wing area. {{gli|Contour}} and {{gli|down feathers}} are generally identified as the main targets, although in some cases, {{gli|tail}} and {{gli|flight feathers}} are affected. Although feather-plucking shares characteristics with {{gli|feather pecking}}, commonly seen in commercial poultry, the two behaviours are currently considered to be distinct, as in the latter, the birds peck at and pull out the feathers of other individuals.}}

{{Term|feather tract}}

{{defn|See: {{gli|pterylae}}.}}

{{Term|term=fecal sac|content=fecal sac {{anchor|fecal sac|fecal sacs|faecal sac|faecal sacs}} }}

{{Main|Fecal sac}}

{{defn|Also, faecal sac. A mucous membrane, generally white or clear with a dark end,{{cite book|last1=Choiniere|first1= J.|last2=Mowbray Golding| first2= C.|last3=Vezo|first3=T.|year=2005|title=What's That Bird?|page=[https://archive.org/details/whatsthatbirdget00choi/page/33 33]|publisher=Storey Publishing|isbn=978-1-58017-554-8|url=https://archive.org/details/whatsthatbirdget00choi/page/33}} that surrounds the feces of some species of {{gli|nestling}} birds,{{Harvnb|Sibley, et al.|2001|p=78}} and allows parent birds to more easily remove fecal material from the nest. The nestling usually produces a fecal sac within seconds of being fed; if not, a waiting adult may prod around the youngster's cloaca to stimulate excretion.{{Harvnb|Campbell|Lack|1985|p=433}} Young birds of some species adopt specific postures or engage in specific behaviours to signal that they are producing fecal sacs.{{cite book|last = O'Connor |first=R. J.|year=1984|title=The Growth and Development of Birds| page=174| publisher=Wiley Interscience| isbn=978-0-471-90345-1}} For example, nestling curve-billed thrashers raise their posteriors in the air, while young cactus wrens shake their bodies.{{cite magazine|last=Ricklefs|first=R. E.|year= 1996|magazine=The Wilson Bulletin|title=Behavior of Young Cactus Wrens and Curve-billed Thrashers|volume=78|issue= 1|pages=47–56|url= http://elibrary.unm.edu/sora/Wilson/v078n01/p0047-p0056.pdf|archive-url=https://web.archive.org/web/20081010223857/http://elibrary.unm.edu/sora/Wilson/v078n01/p0047-p0056.pdf|archive-date=October 10, 2008|url-status=dead}} Other species deposit the sacs on the rim of the nest, where they are likely to be seen (and removed) by parent birds. Not all species generate fecal sacs. They are most prevalent in {{gli|passerines}} and their near relatives, which have young that remain in the nest for longer periods.}}

File:Goose filoplume illustration-1895.jpg

{{Term|term=filoplume|content=filoplume {{anchor|filoplumes|filoplume feather|filoplume feathers}} }}

{{defn|Also, filoplume feather; hair feather, thread feather. A hairlike type of feather that, if present in a bird (they are entirely absent in ratites) grows alongside the contour feathers. The typical filoplume is silky in appearance, lacks pith and a {{gli|superior umbilicous}} opening, has a very slender, straight shaft lacking differentiation into {{gli|calamus}} and {{gli|rachis}}, and is naked or has only a few {{gli|barbs}} (that lack cross-attachment) at the distal end. They are closely associated with {{gli|contour feathers}} and often entirely hidden by them, with one or two filoplumes attached and sprouting from near the same point of the skin as each contour feather, at least on a bird's head, neck and trunk.{{cite book|last=Nitzsch|first=Christian Ludwig|title=Nitzsch's Pterylography|url=https://books.google.com/books?id=O_NFAAAAcAAJ&pg=PA14|year=1867|publisher=Ray Society|page=14}}{{Harvnb|Chandler|1916|p=261}} Filoplume feathers host a cluster of sensory corpuscles at their base,{{Harvnb|Proctor|Lynch|1998|p=96}} that serve to detect air currents that affect contour and flight feathers. Filoplumes are one of the three major classes of feathers, the others being {{gli|pennaceous}} and {{gli|plumulaceous}} feathers.}}

{{Term|term=flange|content=flange {{anchor|flanges|recurved margin|recurved margins|feather flange|feather flanges}} }}

{{defn|Also, recurved margin. "The thickened dorsal edge of the bases of pennaceous {{gli|barbules}}, generally recurved in proximal barbules, and frequently so in distal barbules also"{{Harvnb|Chandler|1916|p=253}} which anchor the {{gli|hooklets}}. (See diagram; refer to figures 3 [in which the flange is referred to as the "folded edge"] and 6 [in which the mechanism of interlocking between a flange and {{gli|hooklet}} is shown].)}}

{{Term|term=flanks|content=flanks {{anchor|flank}} }}

{{defn|The {{gli|topography|topographical}} region of the {{gli|underparts}}{{efn|In relation to flanks being defined as under parts, in the treatise Ornithology in Laboratory and Field, the author states: "[a]lthough technically the sides of the body belong to both the {{gli|upper parts}} and the {{gli|lower parts}}, the imaginary line separating the two surfaces is so high on the trunk that the sides of the body are generally considered under parts only."}} sketched "between the posterior half of the abdomen and the {{gli|rump}}".}}

{{Term|term=fledge|content=fledge {{anchor|fledging|fledges|fledged}} }}

{{defn|Also, fledging. The stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight, or describing the act of a chick's parents in raising it to that time threshold.{{cite book|last=Eastman|first=John|title=Birds of Field and Shore: Grassland and Shoreline Birds of Eastern North America|url=https://books.google.com/books?id=lfSldAchKFYC&pg=PR13|year=2000|publisher=Stackpole Books|isbn=978-0-8117-2699-3|page=13}}}}

{{Term|term=fledgling|content=fledgling {{anchor|fledglings}} }}

{{defn|A juvenile bird during the period it is venturing from or has left the {{gli|nest}} and is learning to run and fly; a young bird during the period immediately after {{gli|fledging}}, when it is still dependent upon parental care and feeding.{{cite book|last=Stiteler|first=Sharon |title=1001 Secrets Every Birder Should Know: Tips and Trivia for the Backyard and Beyond|url=https://books.google.com/books?id=v6UAQB0Ra6QC&pg=PT389|year=2013|publisher=Running Press|location=London|isbn=978-0-7624-4832-6|page=389}}}}

{{Term|term=flight|content=flight {{anchor|fly|flying|bird flight|bird flying}} }}

{{defn|Most birds can fly, which distinguishes them from almost all other vertebrate classes (cf. bats and pterosaurs). Flight is the primary means of locomotion for most bird species and is used for breeding, feeding and predator avoidance and escape. Birds have various adaptations for flight, including a lightweight skeleton, two large flight muscles, the pectoralis (which accounts for 15% of the total mass of the bird) and the supracoracoideus, as well as modified forelimbs (wings) that serve as aerofoils.{{Harvnb|Gill|1995|p=136, et seq.}} Wing shape and size generally determine a bird species' type of flight; many birds combine powered, flapping flight with less energy-intensive soaring flight. About 60 extant bird species are flightless, as were many extinct birds.{{harvnb|Roots|2006|p=various}} Flightlessness often arises in birds on isolated islands, probably due to limited resources and the absence of land predators.{{cite magazine|last=McNab |first=Brian K. |date=October 1994 |title=Energy Conservation and the Evolution of Flightlessness in Birds |magazine=The American Naturalist |volume=144 |issue= 4 |pages=628–42 |doi=10.1086/285697 |jstor=2462941}} Though flightless, penguins use similar musculature and movements to "fly" through the water, as do auks, shearwaters and dippers.{{cite magazine|last1=Kovacs |first1=Christopher E. |year=2000 |title=Anatomy and histochemistry of flight muscles in a wing-propelled diving bird, the Atlantic Puffin, Fratercula arctica |magazine=Journal of Morphology |volume=244 |issue= 2 |pages=109–25|doi=10.1002/(SICI)1097-4687(200005)244:2<109::AID-JMOR2>3.0.CO;2-0 |pmid=10761049 |last2=Meyers |first2=RA}}}}

File:Parts of feather modified.jpg

{{Term|term=flight feather|content=flight feather {{anchor|flight feathers|Pennae volatus}} }}

{{main|Flight feather}}

{{defn|Also, Pennae volatus.{{cite book|title=Handbook of Avian Anatomy: Nomina Anatomica Avium|last=Baumel|first=Julian J.|year=1993|publisher=Nuttall Ornithological Club}} The long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the tail or wings of a bird; those on the tail are called {{gli|rectrices}} (singular: {{gli|rectrix}}), while those on the wings are called {{gli|remiges}} (singular: {{gli|remex}}). Based on their location, remiges are subdivided into {{gli|primaries}}, {{gli|secondaries}} and {{gli|tertiaries}}.{{cite book|title=The Century Dictionary and Cyclopedia|last=Whitney|first=William Dwight|publisher=The Century Co| year=1906|series=Entry for "Feather"| url=https://archive.org/details/bub_gb_U_FOAAAAYAAJ| page=[https://archive.org/details/bub_gb_U_FOAAAAYAAJ/page/n624 2], 164|oclc=825679}}}}

{{Term|term=foot paddling|content=foot paddling {{anchor|foot paddling}} }}

{{defn|A foraging behaviour of gulls in which individuals stand at a location, often in shallow water, and perform rapid stepping actions that are thought to make subterranean worms or other food rise to the surface.{{cite magazine |first=P. A.|last=Buckley|date=January–December 1966|title=Foot-paddling in Four American Gulls, with Comments on its Possible Function and Stimulation|magazine=Ethology|volume=23|issue= 4|pages=395–402|pmid=5992179}}}}

{{Term|forehead}}

{{defn|The portion of a bird's head extending "up and back from the {{gli|bill}} to an imaginary line joining the anterior corners of the eyes".}}

{{Term|fovea|content=fovea {{anchor|foveas|foveae|fovea centralis|temporal fovea}} }}

{{Main|Fovea centralis}}

{{defn|Plural: foveas or foveae. A small cavity in the retina of the eye that hosts a large number of light receptors; more than anywhere else on the retina. About one half of bird species with fovea have a single one, but uniquely in birds,{{cite book|last=Walls|first=Gordon L.|title=Bulletin: The Vertebrate Eye and its Adaptive Radiation|chapter-url=https://archive.org/details/vertebrateeyeits00wall/page/188|year=1942|publisher=The Cranbrook Institute of Science|page=188|chapter=Adaptations to Diurnal Activity}} some, such as terns, kingfishers and hummingbirds, have a second fovea,{{cite book|last=Holden|first=Peter |title=RSPB Birds: their Hidden World|url=https://books.google.com/books?id=3XcDCwAAQBAJ&pg=PA245|year=2016|publisher=Bloomsbury Publishing|location=London|isbn=978-1-4729-3224-2|page=245}} called the temporal fovea, that assists in judging speed and distance and increases visual acuity. Birds that do not have a second fovea will sometimes bob their head to improve their visual field.{{Harvnb|Elphick|2016|p=61}}}}

{{Term|term=friction barbules|content=friction barbules {{anchor|friction barbule|locking barbule|locking barbules}} }}

{{defn|A specialized type of {{gli|barbule}} located on the distal part of the inner {{gli|vane}} of {{gli|primary feathers}} on the wings of most flighted birds. Friction barbules support lobe-shaped ("lobular") {{gli|barbicels}} that are broader than the typical barbicel hosted by other vaned feathers, and which in turn support more {{gli|hooklets}}. The theory is that the augmented surface area and other adaptations significantly increases grip through friction when the outer web of barbs of one primary feather come into contact and rub against the inner web of barbs of another primary feather it overlays, thereby preventing slippage during the rigors of flight.{{Harvnb|Gill|1995|p=84}}{{cite magazine|magazine=Bulletin of the British Ornithologists' Club|last=Davison|first=G. W. H.|volume=103|issue=3|title=Notes on the Extinct Argusianus Bipuntatus|page=87|date=November 1982|url=https://www.biodiversitylibrary.org/item/123798#page/103/mode/1up|access-date=2018-01-14|archive-date=2017-08-05|archive-url=https://web.archive.org/web/20170805190417/http://www.biodiversitylibrary.org/item/123798#page/103/mode/1up|url-status=live}} Friction barbules are found only on those parts of primary feathers that are in "zones of overlap" with neighboring primaries. The theory (and the use of "friction" in the title of the defined phrase) has been criticized. In Avian Flight (2005), the author notes that "most birds open and close their wings during every wing beat cycle", and proposes that the energetic cost to overcome friction during the "wing extension and flexion" of each beat cycle would be prohibitive. Offered instead is the theory that the function of these specialized barbules is to lock the primary feathers together on the wings' downstroke, during which high pressure from below the wings' surface would otherwise tend to cause the feathers to spread.{{cite book|last=Videler|first=John J.|title=Avian Flight|url=https://books.google.com/books?id=5Xr9NZdgzP0C&pg=PA58|year=2005|publisher=OUP Oxford|isbn=978-0-19-929992-8|pages=58–61}}}}

{{Term|term=frontal shield|content=frontal shield {{anchor|frontal shields|facial shield|frontal plate|facial shields|frontal plates|face shield|face shields}} }}

{{main|Frontal shield}}

{{defn|Also facial shield; face shield; frontal plate. A hard or fleshy plate extending from the base of the {{gli|upper mandible}} over the {{gli|forehead}} of several bird species including some water birds in the rail family, especially the gallinules and moorhens, swamphens and coots, as well as in jacana.{{Harvnb|Campbell|Lack|1985|p=533}} While most face shields are made up of fatty tissues, some birds, such as certain turacos, e.g., the red-crested turaco, have face shields that are hard extensions of the mandible.{{cite book|last=Grouw|first=Katrina Van |title=The Unfeathered Bird|url=https://books.google.com/books?id=wYrPAwRh95gC&pg=PA58|year=2013|publisher=Princeton University Press|isbn=978-0-691-15134-2|page=58}} The size, shape and colour may exhibit testosterone-dependent variation in either sex during the year.{{cite magazine |vauthors=Alvareza F, Sanchez CS, Angulo S |year= 2005|title= The frontal shield of the moorhen: sex differences and relationship with body condition|magazine= Ethology, Ecology & Evolution|volume=17|issue= 2|pages=135–148 |doi= 10.1080/08927014.2005.9522603|url= |citeseerx= 10.1.1.158.6095|s2cid= 85892241}} Functionality appears to relate to protection of the face while feeding in or moving through dense vegetation, as well as to courtship display and territorial defence.{{cite magazine |last=Gullion|first=Gordon W.|year=1951|title=The frontal shield of the American Coot|magazine=Wilson Bulletin|volume=63|issue= 3|pages=157–166}} Compare: {{gli|casque}}.}}

{{Term|term=furcula|content=furcula {{anchor|furculae|wishbone|wishbones|wish-bone|wish-bones|merry thought|merry-thought}} }}

{{defn|Also, wishbone; merry-thought. From the Latin for "little fork", the furcula is a forked bone, also found in some dinosaurs, located below the neck and formed by the fusion of the two clavicles. Its primary function is in the strengthening of the thoracic skeleton to withstand the rigors of flight. It works as a strut between a bird's shoulders, and articulates to each of a bird's scapulae. In conjunction with the coracoid and the scapula, it forms a unique structure called the triosseal canal, which houses a strong tendon that connects the supracoracoideus muscles to the humerus. This system is responsible for lifting the wings during a recovery stroke. As the thorax is compressed by the flight muscles during a downstroke, the upper ends of the furcula spread apart, expanding by as much as 50% of its resting width, and then contract. Furcula may also aid in respiration, by helping to pump air through the air sacs.{{Harvnb|Gill|1995|pp=134–136}}{{Cite OED|Furcula}}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

File:House sparrow portrait.jpg is the yellowish region at the base of the beak.]]

{{Term|gape|content=gape {{anchor|gapes}} }}

{{defn|The interior of the open mouth of a bird.{{cite book | title=Newman's birds by colour | first=Kenneth B. | last=Newman | publisher=Struik | year=2000 | page=14 | isbn=978-1-86872-448-2}} The width of the gape can be a factor in the choice of food.{{cite magazine|title=Fruit size, gape width and the diets of fruit-eating birds|last1=Wheelwright|first1=NT|volume=66|issue= 3|year=1985|pages=808–818|url=http://www.bowdoin.edu/faculty/n/nwheelwr/pdf/FruitsizeGape.pdf|doi=10.2307/1940542|magazine=Ecology|jstor=1940542|archive-url=https://web.archive.org/web/20160408055802/http://www.bowdoin.edu/faculty/n/nwheelwr/pdf/FruitsizeGape.pdf|archive-date=April 8, 2016|url-status=dead}}}}

{{Term|gape flange|content=gape flange {{anchor|gape flanges}} }}

{{defn|The region where the {{gli|upper mandible|upper}} and {{gli|lower mandible|lower}} mandibles join together at the base of the {{gli|beak}}. When born, the chick's gape flanges are fleshy. As it grows into a {{gli|fledgling}}, the gape flanges remain somewhat swollen and can thus be used to recognize that a particular bird is young.{{Cite web| url=http://www.birdwatchersdigest.com/site/backyard_birds/bird_Id/mystery_birds.aspx| title=Backyard Mystery Birds| first=Julie| last=Zickefoose| publisher=Bird Watcher's Digest| access-date=January 29, 2017| date=July 25, 2014| archive-date=December 13, 2010| archive-url=https://web.archive.org/web/20101213051538/http://birdwatchersdigest.com/site/backyard_birds/bird_Id/mystery_birds.aspx| url-status=live}} Gape flanges can serve as a target for food for parents, and when touched, stimulate the nestling to open its mouth to eat.{{Harvnb|Elphick|2016|p=71}}}}

{{Term|gizzard|content=gizzard {{anchor|gizzards|ventriculus|ventriculae|koilin|gastric mill|gigerium}} }}

{{Main|Gizzard}}

{{defn|Also, ventriculus; gastric mill; gigerium. A specialized stomach organ found in the digestive tract of some birds constructed of thick muscular walls that is used for grinding up food, often aided by particles of stone or grit. Food, after going through the {{gli|crop}} and {{gli|proventriculus}}, passes into the gizzard where it can be ground with previously swallowed stones and passed back to the proventriculus, and vice versa. Bird gizzards are lined with a tough layer made of a carbohydrate-protein complex called koilin, that protects the muscles in the gizzard.{{Harvnb|Pettingill|1985|p=77}}{{cite book|last=Nyakupfuka|first=Andrew|title=Global Delicacies: Diversity, Exotic, Strange, Weird, Relativism.|url=https://books.google.com/books?id=G7UEER5uKwQC&pg=PA120|date=April 3, 2013|publisher=Balboa Press|isbn=978-1-4525-6791-4|page=120}}}}

{{Term|gleaning|content=gleaning {{anchor|glean|foliage gleaning|hover-gleaning|crevice-gleaning}} }}

{{Main|Gleaning (birds)}}

{{defn|Specialized cases: foliage gleaning; hover-gleaning; crevice-gleaning. The strategy of gleaning over surfaces by birds to catch invertebrate prey—chiefly insects and other arthropods—by plucking them from foliage or the ground, from crevices such as of rock faces and under the eaves of houses, or even, as in the case of ticks and lice, from living animals. Gleaning the leaves and branches of trees and shrubs is called "foliage gleaning", which can involve a variety of styles and maneuvers. Some birds, such as the common chiffchaff{{cite book|last1=Peterson|first1=Roger|author-link= Roger Tory Peterson|last2 = Mountfort|first2=Guy|last3=Hollom|first3=P.A.D.|title=A Field Guide to the Birds of Britain and Europe|publisher=Collins|location = London|year=1954|page=251}} of Eurasia and the Wilson's warbler of North America, feed actively and appear energetic. Some will even hover in the air near a twig while gleaning from it; this behaviour is called "hover-gleaning". Other birds are more methodical in their approach to gleaning, even seeming lethargic as they perch upon and deliberately pick over foliage. This behaviour is characteristic of the bay-breasted warbler{{cite book|last1=Dunn|first1=Jon|last2=Garrett|first2=Kimball|title=Warblers|publisher=Peterson Field Guides|location=New York|year=1997|pages = 18, 377, 437, 470, 551|isbn=978-0-395-78321-4}} and many vireos. Another tactic is to hang upside-down from the tips of branches to glean the undersides of leaves. Tits such as the familiar black-capped chickadee are often observed feeding in this manner. Some birds, like the ruby-crowned kinglet, use a combination of these tactics. "Crevice-gleaning" is a niche particular to dry and rocky habitats. Gleaning birds are typically small with compact bodies and have small, sharply pointed {{gli|beaks}}. Birds often specialize in a particular niche, such as a particular stratum of forest or type of vegetation.{{Harvnb|Sibley, et al.|2001|pages=360–361, 377, 390, 404, 427, 435–436, 441, 451, 545}}}}

{{Term|gnathotheca}}

{{defn|The {{gli|rhamphotheca}} (thin horny sheath of keratin) covering the {{gli|lower mandible}}.}}

{{Term|gonys}}

{{Main|Beak#Gonys}}

{{further|#gonydeal angle|#gonydeal spot}}

{{defn|The ventral ridge of the {{gli|lower mandible}}, created by the junction of the bone's two rami, or lateral plates.}}

{{Term|gonydeal angle|content=gonydeal angle {{anchor|gonydeal angles|gonydeal-angle|gonydeal-angles|gonydeal expansion|gonydeal expansions|gonydeal-expansion|gonydeal-expansions}} }}

{{Main|Beak#Gonys}}

{{defn|Also, gonydeal expansion. The proximal end of the junction created by the {{gli|gonys}} two rami, or lateral plates—the place where the two plates separate. The size and shape of the gonydeal angle can be useful in identifying between otherwise similar species.{{Harvnb|Howell|2007|p=23}}}}

{{Term|gonydeal spot|content=gonydeal spot {{anchor|gonydeal spots|gonydeal-spot|gonydeal-spots}} }}

{{Main|Beak#Gonys}}

{{defn|The spot near the gonydeal expansion, in adults of many bird species but especially in gulls, usually reddish or orangish in colour, that triggers begging behaviour. Gull chicks, for example, peck at the spot on its parent's bill, which in turn stimulates the parent to {{gli|regurgitate}} food.{{cite book |last1=Russell |first1=Peter J. |first2=Stephen L. |last2=Wolfe |first3=Paul E. |last3=Hertz |first4=Cecie |last4=Starr |title=Biology: The Dynamic Science |volume=2 |year=2008 |publisher=Thomson Brooks/Cole |location=Belmont, CA |isbn=978-0-495-01033-3 |page=1255}}}}

File:Costa's hummingbird (Calypte costae)-cropped.jpeg

{{Term|gorget|content=gorget {{anchor|gorgets}} }}

{{defn|A patch of coloured feathers found on the throat or upper breast of some species of birds.{{Harvnb|Campbell|Lack|1985|p=254}} It is a feature found on many male hummingbirds, particularly those found in North America, whose gorgets are typically iridescent.{{cite book |first=Steve N. G.|last=Howell|title=Hummingbirds of North America: The Photographic Guide|year=2002|publisher=Academic Press|isbn=978-0-12-356955-4|page=1}} Other species having gorgets include the purple-throated fruitcrow{{cite book |title=The Birds of South America: The suboscine passerines |first1=Robert S. |last1=Ridgely |first2=Guy |last2=Tudor |first3=William L. |last3=Brown |page=771 |year=1994 |location=Austin, TX |publisher=University of Texas Press |isbn=978-0-292-77063-8}} and the chukar partridge.{{cite book |title=The Chukar Partridge: Its Introduction, Life History and Management |first=Glen C. |last=Christensen |page=33 |location=Reno, NV |publisher=Nevada Department of Fish and Game |year=1970}} The term is derived from the gorget used in military armor to protect the throat.{{Cite podcast|url=http://www.audubon.org/news/a-hummingbirds-shining-armor|title=A Hummingbird's Shining Armor|publisher=BirdNote|work=BirdNote|date=8 April 2015|last=Sundstorm|first=Bob|others=Narrated by Mary McCann|access-date=26 December 2017|archive-date=27 December 2017|archive-url=https://web.archive.org/web/20171227125137/http://www.audubon.org/news/a-hummingbirds-shining-armor|url-status=live}}}}

{{Term|grooming}}

{{defn|See entry for {{gli|preening}}.}}

{{Term|gular region|content=gular region {{anchor|gular|gulars|gula}} }}

{{defn|The posterior part of the underside of a bird's head, described as "a continuation of the chin to an imaginary line drawn between the angles of the jaw". See also: {{gli|gular skin}}.}}

{{Term|gular skin|content=gular skin {{anchor|gular|gular sac|gular sacs|gular pouch|gular pouches|throat sac|gular flutter|gular fluttering|gular panting|gular pant}} }}

{{defn|Also defined, gular sac / throat sac; gular pouch; gular flutter. Describes the {{gli|gular region}} when it is featherless. In many species, the gular skin forms a flap, or gular pouch, which is generally used to store fish and other prey while hunting. In many others, such as frigatebirds, the gular skin may overlie a sac—the gular sac or throat sac—that may be dramatically inflated by males during courtship display. In some species the gular region is used for thermoregulation, by the fluttering of the hyoid bone and surrounding muscles, vibrating as many as 735 times per minute, which causes an increase in heat dissipation from the gular skin.{{cite book|last1=Morris|first1=Christopher G.|author2=Academic Press|title=Academic Press Dictionary of Science and Technology|url=https://books.google.com/books?id=nauWlPTBcjIC&pg=PA971|year=1992|publisher=Gulf Professional Publishing|isbn=978-0-12-200400-1|page=971}}{{cite book|last1=Day|first1=Leslie|last2=Riepe|first2=Don|title=Field Guide to the Neighborhood Birds of New York City|url=https://books.google.com/books?id=EwTHCQAAQBAJ&pg=PT36|year=2015|publisher=JHU Press|isbn=978-1-4214-1617-5|page=36}}{{cite book|last=Lederer|first=Roger|title=Beaks, Bones and Bird Songs: How the Struggle for Survival Has Shaped Birds and Their Behavior|url=https://books.google.com/books?id=v9YlDAAAQBAJ&pg=PT157|year=2016|publisher=Timber Press|isbn=978-1-60469-752-0|page=157}}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|hallux|content=hallux {{anchor|hind toe|hind toes|incumbent hallux|elevated hallux|first digit|incumbent}} }}

{{Main|Bird feet and legs#Toes and unfused metatarsals}}

{{defn|Also, hind toe; first digit. Specialized types: incumbent and elevated. A bird's usually rear-facing toe; its hind toe. When it is attached near the base of the {{gli|tarsometatarsus|metatarsus}} it is termed incumbent, and when projecting from a higher portion of the metatarsus (as in rails), it is termed elevated. The hallux is a bird's first digit, in many birds being the sole rear-facing toe (including in most {{gli|passerine}} species that have {{gli|anisodactylous}} feet) and is homologous to the human big toe.{{sfn|Lovette|Fitzpatrick|2016|p=181}}{{Harvnb|Feduccia|1999|p=13}}{{Harvnb|Bird|2004|p=4}}}}

{{Term|home range|content=home range {{anchor|territory|territories|temporary territory|permanent territory|breeding territory|non-breeding territory|home ranges|homerange|homeranges|home-range|home-ranges}} }}

{{defn|Also defined: territory. The area of land in which a bird performs most of its activities. When the area is guarded (in whole or in part) from individuals of the same species it is called a territory.{{cite magazine|last1=Odum|first1=Eugene P.|last2=Kuenzler|first2=Edward J.|title=Measurement of territory and home range size in birds|magazine=The Auk|volume=72|issue= 2|year=1955|pages=128–137|issn=0004-8038|doi=10.2307/4081419|jstor=4081419}} These territories may be temporary or permanent, breeding or non-breeding. Breeding territories may be of four types: i) an all-purpose territory where all activities are conducted; ii) a separate breeding and feeding territory (or just a breeding territory, with foraging conducted outside of it); iii) a territory surrounding the nest and a very small area outside of it; iv) a small territory used solely for display within a {{gli|lek}}.{{harvnb|Elphick|2016|pp=135–136}} The size of the home range can be affected by what food a bird eats and how much the bird weighs. Birds that weigh more usually have larger ranges, and {{gli|carnivores}} on average have larger ranges than non-carnivores.{{cite magazine|last1=Harestad|first1=A. S.|last2=Bunnel|first2=F. L.|title=Home range and body weight--a reevaluation|magazine=Ecology|volume=60|issue= 2|year=1979|pages=389–402|issn=0012-9658|doi=10.2307/1937667|jstor=1937667}}}}

{{Term|Humphrey–Parkes terminology}}

{{Main|Humphrey–Parkes terminology}}

{{defn|A system of nomenclature for the {{gli|plumage}} of birds proposed in 1959 by Philip S. Humphrey and Kenneth C. Parkes to make the terminology for describing bird plumages more uniform.{{Harvnb|Pettingill|1985|pp=98, 190}} Examples of Humphrey–Parkes terminology versus traditional terminology may be seen in the entries for {{gli|prealternate moult}} and {{gli|prebasic moult}}.}}

{{Term|hyoid apparatus|content=hyoid apparatus {{anchor|hyoid apparatuses|tongue bone|basihyal|urohyal|ceratobranchial|epibranchial}} }}

{{defn|The system of bones to which the tongue is attached. It usually includes the tongue bone, to which the tongue is actually attached,{{Harvnb|Elphick|2016|pp=25–26}} the basihyal, behind the tongue bone, the urohyal, itself behind the basihyal, a pair of ceratobranchial bones, and a pair of epibranchial.{{cite magazine|last1=Jung|first1=Jae-Young|last2=Naleway|first2=Steven E.|last3=Yaraghi|first3=Nicholas A.|last4=Herrera|first4=Steven|last5=Sherman|first5=Vincent R.|last6=Bushong|first6=Eric A.|last7=Ellisman|first7=Mark H.|last8=Kisailus|first8=David|last9=McKittrick|first9=Joanna|title=Structural analysis of the tongue and hyoid apparatus in a woodpecker|magazine=Acta Biomaterialia|volume=37|year=2016|pages=1–13|issn=1742-7061|doi=10.1016/j.actbio.2016.03.030|pmid=27000554|pmc=5063634}} The latter two bones form the hyoid horns, which are contained in a pair of fascia vaginalis. This allows the tongue to slide out smoothly. The hyoid apparatus is attached to the larynx.}}

{{Glossary end}}

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{{Term|in pin|content=in pin}}{{Defn|See #pin feather}}

{{Term|inferior umbilicus|content=inferior umbilicus {{anchor|inferior umbilicae|proximal umbilicae|proximal umbilicae}} }}

{{defn|Also, proximal umbilicus. A small opening located at the bottom tip of a feather's shaft, i.e., at the base of the {{gli|calamus}}, that is embedded within the skin of a bird. The growth of the feather is fed by the flow through the inferior umbilicus of a nutrient (or nutritive) pulp of highly vascular dermal cells (sometimes called the nutritive dermis; a part of what is termed the Malpighian layer), that in turn produce a nourishing plasma. In mature feathers the opening is sometimes sealed over by a keratinous plate.{{Cite EB1911|wstitle=Feather|volume=10|page=227 |first=William Plane |last=Pycraft}}{{cite magazine|magazine=Journal of the Department of Agriculture|title=The origin of feathers from the scales of reptiles|page=67|volume=5|issue=1|url=http://journals.co.za/content/jdagr/5/1/AJA0000020_1267|last=Duerden|first=J.E.|date=July 1922|access-date=2017-04-17|archive-date=2017-04-18|archive-url=https://web.archive.org/web/20170418082840/http://journals.co.za/content/jdagr/5/1/AJA0000020_1267|url-status=live}} Compare: {{gli|superior umbilicus}}.}}

{{Term|inner wing|content=inner wing {{anchor|inner wings|outer wing|outer wings|innerwing|innerwings|outerwing|outerwings}} }}

{{defn|Also defined: outer wing. The inner wing of a bird is that portion of the wing stretching from its connection to the body and through the "wrist" joint. The outer wing stretches from the wrist to the wingtip.{{Harvnb|Scott|2010|p=43}}}}

{{Term|iris|content=iris {{anchor|irises}} }}

{{defn|The coloured outer ring that surrounds a bird's {{gli|pupil}}. Though brown predominates, the iris may be of or include a variety of colours—red, yellow, grey, blue, etc.—and the colouration may vary according to the age, sex and species.{{cite book|last=Jasper|first=Theodore|title=Studer's Popular Ornithology …|url=https://books.google.com/books?id=WvI0AQAAMAAJ&pg=PP24|year=1878|publisher=J.H. Studer & Company|location=Columbus, OH|page=2}}}}

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{{Term|jizz|content=jizz {{anchor|gestalt}} }}

{{Main|Jizz (birding)}}

{{defn|Also, gestalt,{{cite book|last=Zimmer|first=Kevin J.|title=Birding in the American West: A Handbook|url=https://books.google.com/books?id=TMtB8CG767EC&pg=PA47|year=2000|publisher=Cornell University Press|isbn=978-0-8014-8328-8|page=47}} of which the term may be a corruption{{cite magazine|magazine=Canberra Bird Notes|volume=21|issue=1|title=The Etymology of Jizz|last1=McDonald|first1=David|url=https://www.scribd.com/doc/16209649/The-etymology-of-jizz|date=March 1996|pages=2–11|access-date=2017-09-09|archive-date=2016-04-18|archive-url=https://web.archive.org/web/20160418141654/https://www.scribd.com/doc/16209649/The-etymology-of-jizz|url-status=live}} (or possibly deriving from the air force acronym GISS for "General Impression of Size and Shape (of an aircraft)", associated with World War II lingo; though this derivation may by anachronistic as jizz was first used in birdwatching as early as 1922),{{Cite OED|Jizz}} it describes the overall impression or appearance of a bird—"the indefinable quality of a particular species, the 'vibe' it gives off"{{cite book|first=Sean|last=Dooley|title=The Big Twitch|page=78|year=2005|publisher=Allen & Unwin|isbn=978-1-74114-528-1}}—garnered from such features as shape, posture, flying style or other habitual movements, size and colouration combined with voice, habitat and location.{{cite book|author=Dave Madden|title=The Authentic Animal: Inside the Odd and Obsessive World of Taxidermy|url=https://books.google.com/books?id=Uf11AjcpIpMC&pg=PA127|date=August 2, 2011|publisher=St. Martin's Press|isbn=978-1-4299-8762-2|pages=127–}}{{cite book|author=Hugh Harrop|title=Shetland sea mammal report 2003|url=https://books.google.com/books?id=Ex0XAQAAIAAJ|year=2004|publisher=Shetland Sea Mammal Group}}{{cite book|author=Andrew Tyzack|title=Drawing and Painting Insects|url=https://books.google.com/books?id=HIR8AwAAQBAJ&pg=PT147|date=June 30, 2013|publisher=Crowood Press, Limited|isbn=978-1-84797-625-3|pages=147–}} Example use: "It had the jizz of a thrush, but I couldn't make out what kind."}}

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{{Term|keel|content=keel {{anchor|keels|carina|carinum}} }}

{{defn|Also, carina. An extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for {{gli|flight}}. Keels do not exist on all birds; in particular, some flightless birds lack a keel structure. Historically, the presence or absence of a pronounced keel structure was used as a broad classification of birds into two orders: Carinatae (from Latin carina, 'keel'), having a pronounced keel; and ratites (from Latin ratis, 'raft'—referring to the flatness of the sternum), having a subtle keel structure or lacking one entirely. However, this classification has fallen into disuse as evolutionary studies have shown that many flightless birds have evolved from flighted birds.{{cite web|last=Cummins|first=Jim|date=April 1, 1996|url=http://numbat.murdoch.edu.au/Anatomy/avian/avian2.html|title=Anatomy of Flight|access-date=March 14, 2017|url-status=bot: unknown|archive-url=https://web.archive.org/web/20050211095240/http://numbat.murdoch.edu.au/Anatomy/avian/avian2.html|archive-date=February 11, 2005}}{{cite web|last=Ramel|first=Gordon|url=http://www.earthlife.net/birds/anatomy.html|title=The Anatomy of Birds|publisher=Earth-Life Web Productions|access-date=March 14, 2017|archive-date=February 7, 2005|archive-url=https://web.archive.org/web/20050207193812/http://www.earthlife.net/birds/anatomy.html|url-status=live}}}}

{{Term|kleptoparasitism|content=kleptoparasitism {{anchor|kleptoparasite}} }}

{{Main|Kleptoparasitism}}

{{defn|A bird's propensity to steal food from other birds, either opportunistically, or on a regular basis.{{harvnb|Elphick|2016|p=129}}}}

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{{Term|lateral throat-stripe|content=lateral throat-stripe {{anchor|lateral throat-stripes|lateral throat stripe|lateral throat stripes}} }}

{{defn| A usually dark stripe of colour bordering the throat below both the {{gli|moustachial stripe}} and the {{gli|submoustachial stripe}}, if any.}}

{{Term|lek|content=lek {{anchor|leks|lekking|lek mating|lek matings|lek polygyny|exploded lek|exploded leks|dispersed lek|dispersed leks}} }}

{{Main|Lek mating}}

{{defn|Also defined: lekking; dispersed lek. An aggregation of male birds gathered to engage in competitive displays (known as lekking) that may entice visiting females that are assessing prospective partners for copulation.{{cite magazine|last1=Fiske|first1=Peder|last2=Rintamäki|first2=Pekka T.|last3=Karvonen |first3=Eevi|date= January 1998|title=Mating success in lekking males: a meta-analysis|magazine=Behavioral Ecology|volume=9|issue= 4|pages=328–338|doi=10.1093/beheco/9.4.328|doi-access=free}} These males are usually in sight of each other, but when they are only in earshot, it is called a dispersed lek or an exploded lek. Mating usually occurs on the display area.{{Harvnb|Elphick|2016|p=151}}}}

{{Term|lore|content=lore {{anchor|lores|loreal}} }}

{{see also|Lore (anatomy)}}

{{defn|Adj. form: loreal. The {{gli|topography|topographical}} region of a bird's head between the eye and the {{gli|beak}} on the sides of the head.{{Harvnb|Pettingill|1985|p=9}}}}

{{Term|lower mandible}}

{{Main|Beak#Mandibles}}

{{defn|Also, mandible. The lower part of a bird's {{gli|bill}} or beak, roughly corresponding to the lower jaw of mammals, it is supported by a bone known as the inferior maxillary bone—a compound bone composed of two distinct ossified pieces. These ossified plates (or rami), which can be U-shaped or V-shaped, join distally (the exact location of the joint depends on the species) but are separated proximally, attaching on either side of the head to the quadrate bone. The jaw muscles, which allow the bird to close its beak, attach to the proximal end of the lower mandible and to the bird's skull. The muscles that depress the lower mandible are usually weak, except in a few birds such as the starlings (and the extinct Huia), which have well-developed digastric muscles that aid in foraging by prying or gaping actions.{{cite magazine|last1=Mayr|first1=Gerald|year=2005|title=A new eocene Chascacocolius-like mousebird (Aves: Coliiformes) with a remarkable gaping adaptation|magazine=Organisms, Diversity & Evolution|volume=5|issue=3|pages=167–171|url=http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/chascacocolius.pdf|doi=10.1016/j.ode.2004.10.013|access-date=2017-01-19|archive-date=2016-04-11|archive-url=https://web.archive.org/web/20160411194714/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/chascacocolius.pdf|url-status=live}} In most birds, these muscles are relatively small as compared to the jaw muscles of similarly sized mammals.{{cite book |title=The Inner Bird: Anatomy and Evolution |first1=Gary W. |last1=Kaiser |publisher=UBC Press |location=Vancouver, BC |page=19 |year=2007 |isbn=978-0-7748-1343-3}} The outer surface is covered in thin horny sheath of keratin called {{gli|rhamphotheca}}, specially called {{gli|gnathotheca}} in the lower mandible. Compare: {{gli|upper mandible}}.}}

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File:Preening bird (Unsplash).jpg {{gli|preening}}; one of many {{gli|maintenance behaviours}}|alt=Bird with a wing outstretched, rearranging feathers with the tip of its bill]]

{{Term|maintenance behaviour|content=maintenance behaviour {{anchor|maintenance behaviours|maintenance behavior|maintenance behaviors|comfort behaviour|comfort behavior|comfort behaviours|comfort behaviors}} }}

{{defn|Also, comfort behaviour. The name given to any behaviour or activity which a bird uses to maintain its plumage and soft parts: {{gli|preening}}, bathing, {{gli|anting}}, sunbathing, stretching, scratching, and other such activities.{{cite book |first1=Donald W. |last1=Stokes |first2=Lillian Q. |last2=Stokes |name-list-style=amp |title=Stokes Backyard Bird Book |location=Emmaus, PA |publisher=Rodale |year=2003 |isbn=1-57954-864-4 |page=141}}{{sfn|Campbell|Lack|1985|p=101}} Roosting is also often considered to be a comfort behaviour.{{sfn|Campbell|Lack|1985|pp=101-105}} The phrase is sometimes used more inclusively, to describe all life-sustaining activities, such as feeding, drinking, predator avoidance, and locomotion,{{sfn|Sibley, et al.|2001|pp=55–59}} and even involuntary biological processes, like {{gli|moulting}}.{{cite book|last=Kricher|first=John|title=Peterson Reference Guide to Bird Behavior|url=https://books.google.com/books?id=Lce_DwAAQBAJ&pg=PA20|year=2020|publisher=Houghton Mifflin Harcourt|page=20|isbn=978-1-328-78736-1}}}}

{{Term|mandible}}

{{defn|In birds, the word mandible, alone, usually refers to the {{gli|lower mandible}}.}}

{{Term|mantle}}

{{defn|The forward area of a bird's upper side sandwiched between the {{gli|hindneck}} and the start of the {{gli|back}}. However, in gulls and terns, the term is often used to refer to much of the upper surface below the hindneck.{{Harvnb|Vinicombe|2014|p=15}}}}

{{Term|migration|content=migration {{anchor|migrations|migratory|partial migration|partially migratory|seasonal migration|seasonal migrations}} }}

{{defn|Also defined: partial migration. The regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or only in one direction (dispersal, movement of young away from natal areas). Migration is marked by its annual seasonality.{{Harvnb|Pettingill|1985|pages=232–234}}{{cite book|title=Bird Migration: A General Survey |last1=Berthold|first1=Peter |last2=Bauer|first2=Hans-Günther|last3=Westhead|first3=Valerie|year=2001|isbn=978-0-19-850787-1|publisher=Oxford University Press| location=Oxford}} Non-migratory birds are said to be {{gli|resident}} or sedentary. Approximately 1,800 of the world's bird species are long-distance migrants.{{cite magazine|title=Conservation ecology: area trumps mobility in fragment bird extinctions|last=Sekercioglu|first=C.H.|magazine=Current Biology|year=2007|volume=17|issue= 8|pages=283–286|doi=10.1016/j.cub.2007.04.045|pmid=1743770|doi-access=free}}{{cite magazine|title=Settling down of seasonal migrants promotes bird diversification|last1=Rolland|first1=Jonathan|last2=Jiguet|first2=Frédéric|last3=Jønsson|first3=Knud Andreas|last4=Condamine|first4=Fabien L.|last5=Morlon|first5=Hélène|magazine=Proceedings of the Royal Society B|year=2014|volume=281|issue= 1784|pages=20140473|doi=10.1098/rspb.2014.0473|pmid=24759866|pmc=4043101}} Many bird populations migrate long distances along a flyway. The most common pattern involves flying north in the northern spring to breed in the temperate or Arctic summer, and returning in the autumn to wintering grounds in warmer regions to the south. In the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.{{cite book|last=Newton|first=Ian|year=2008|title=The Migration Ecology of Birds|publisher= Elsevier|isbn=978-0-12-517367-4}} Not all populations within a species may be migratory; this is known as "partial migration". Partial migration is very common in birds of the southern continents. For example, in Australia, 44% of non-passerine birds and 32% of {{gli|passerine}} species are partially migratory.{{cite magazine|last1=Chan|first1=Ken|date=January 2001|title=Partial migration in Australian landbirds: a review|magazine=Emu|volume=101|issue= 4|pages=281–292|doi=10.1071/MU00034}} Many, if not most birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost, e.g., geese in a V-formation may conserve 12–20% of the energy they would otherwise need if flying alone.{{cite magazine|last1=Hummel|first1=D.|last2=Beukenberg|first2=M.|year=1989|title=Aerodynamische Interferenzeffekte beim Formationsfl ug von Vogeln|magazine=J. Ornithol.|volume=130|pages=15–24|doi=10.1007/BF01647158}}{{cite magazine|last1=Cutts|first1=C. J.|last2=Speakman|first2=J. R.|year=1994|title=Energy savings in formation flight of Pink-footed Geese|magazine=J. Exp. Biol.|volume=189|pages=251–261|url=http://jeb.biologists.org/cgi/reprint/189/1/251.pdf|pmid=9317742|issue=1|access-date=2017-04-01|archive-date=2008-10-31|archive-url=https://web.archive.org/web/20081031132021/http://jeb.biologists.org/cgi/reprint/189/1/251.pdf|url-status=live}}}}

{{Term|morph|content=morph {{anchor|morphs|color morph|color morphs|color-morph|color-morphs|colour morph|colour morphs|colour-morph|colour-morphs}} }}

{{defn|Also, colour/color morph. Polymorphic variance in the colouring of the plumage between individuals of the same species, unrelated to age, sex or season. For example, the snow goose has two plumage morphs, white (snow) or grey/blue (blue), thus the common description of individuals as either "snows" or "blues". At one time this colour morph resulted in the "blue goose" being classified as a separate species.{{cite magazine|author=Laboratory of Ornithology, Cornell University|title=Scheduled Birding Trips Around the State Join Newell|url=https://books.google.com/books?id=RTclAQAAMAAJ|date=March 1974|magazine=Scissortail|page=32|issn=0582-2637|volume=24}}{{cite book|last1=Beedy|first1=Ted|last2=Pandolfino|first2=Ed|title=Birds of the Sierra Nevada: Their Natural History, Status, and Distribution|url=https://books.google.com/books?id=lALkK5pRuFUC&pg=PA47|year=2013|publisher=University of California Press|isbn=978-0-520-95447-2|page=47}}}}

{{Term|moult|content=moult {{anchor|moults|molt|molts|moulting|moultings|molting|moltings|wing moult|wing molt|wing moults|wing molts|feather moult|feather moulting|feather molt|feather molting}} }}

{{Main|Moulting#In birds|Flight feather#Moult}}

{{defn|Also, molt (chiefly U.S.) and moulting / molting. The periodic replacement of feathers by shedding old feathers while producing new ones. Feathers are dead structures at maturity which are gradually abraded and need to be replaced. Adult birds moult at least once a year, although many moult twice and a few three times each year. It is generally a slow process, as birds rarely shed all their feathers at any one time; the bird must retain sufficient feathers to regulate its body temperature and repel moisture. The number and area of feathers that are shed varies. In some moulting periods, a bird may renew only the feathers on the head and body, shedding the wing and tail feathers during a later moulting period. Some species of bird become flightless during an annual "wing moult" and must seek a protected habitat with a reliable food supply during that time. Typically, a bird begins to shed some old feathers, then pin feathers grow in to replace the old feathers. As the pin feathers become full feathers, other feathers are shed. This is a cyclical process that occurs in many phases. It is usually symmetrical, with feather loss equal on each side of the body. Because feathers make up 4–12% of a bird's body weight, it takes a large amount of energy to replace them. For this reason, moults often occur immediately after the breeding season, but while food is still abundant. The plumage produced during this time is called {{gli|postnuptial plumage}}.{{harvnb|Terres|1980|pp=616–617}}}}

{{Term|moult strategy|content=moult strategy {{anchor|moulting strategy|moult strategies|moulting strategies|complex alternate strategy|complex basic strategy|simple alternate strategy|simple basic strategy|molt strategy|molt strategies|molting strategy|molting strategies}} }}

{{defn|Specialized types defined: simple basic strategy; simple alternate strategy; complex basic strategy; complex alternate strategy. The pattern of {{gli|moults}} that occurs regularly based on the season and time. There are four main moulting strategies: i) simple basic strategy, in which there is one moult per year, every year; ii) simple alternate strategy, in which there are two moults per year, every year; iii) complex basic strategy, in which there is one moult per year, except in the first year of life, where there is an additional moult; and iv) complex alternate strategy, in which there are two moults per year, except in the first year of life, where there is an additional moult.{{harvnb|Floyd|2008|p=497}}}}

File:New Zealand Pipit Kapiti-Moustachial stripe.jpeg

{{Term|moustachial stripe|content=moustachial stripe {{anchor|mustachial stripes|mustachial stripes|moustachial stripes|moustachial-stripe|moustachial-stripes|mustache stripe|mustache stripes|malar stripe|malar stripes}} }}

{{defn|Also, mustache stripe; whisker stripe; malar stripe. A dark feather colouration line running "obliquely from the {{gli|gape}} down and along the lower border of the {{gli|ear-coverts}}". Compare: {{gli|submoustachial stripe}} and {{gli|lateral throat-stripe}}. Birds with moustachial stripes include some of the pipits as well as buntings.}}

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File:Lesser Whistling Duck (Dendrocygna javanica), Singapore -cropped.jpg. Note the hooked {{gli|nail}} at the tip of the beak.]]

{{Term|nail|content=nail {{anchor|nail|nail (beak)|nail (of beak)|nail of the beak}} }}

{{defn|A plate of hard horny tissue at the tip of the beak of all birds in the family Anatidae (ducks, geese and swans).{{Harvnb|King|McLelland|1985|p=376}} This shield-shaped structure, which sometimes spans the entire width of the beak, is often bent at the tip to form a hook.{{cite book |title=The Wild Fowl of the United States and British Possessions |first=Daniel Giraud |last=Elliot |publisher= F. P. Harper |year=1898 |location=New York, NY |page=xviii |lccn=98001121|url=https://archive.org/details/wildfowluniteds00elligoog }} It serves different purposes depending on the bird's primary food source. Most species use their nails to dig seeds out of mud or vegetation,{{cite book |title=Birds |first=Christopher M. |last=Perrins |year=1974 |publisher=Collins |location=London, UK |isbn=978-0-00-212173-6 |page=24}} while diving ducks use theirs to pry molluscs from rocks.{{cite book |title=Why Ducks Do That: 40 Distinctive Duck Behaviors Explained and Photographed |first=Chuck |last=Petrie |year=2006 |publisher=Willow Creek Press |location=Minocqua, WI |isbn=978-1-59543-050-2 |page=31}} There is evidence that the nail may help a bird to grasp things; species which use strong grasping motions to secure their food (such as when catching and holding onto a large squirming frog) have very wide nails.{{cite book |title=Functional Anatomy of the Feeding Apparatus in Waterfowl (Aves:Anatidae) |last1=Goodman |first1=Donald Charles |first2=Harvey I. |last2=Fisher |publisher=Southern Illinois University Press |location=Carbondale, IL |year=1962 |oclc=646859135 |page=179}} Certain types of mechanoreceptors, nerve cells that are sensitive to pressure, vibration or touch, are located under the nail.{{Harvnb|King|McLelland|1985|p=421}}}}

{{Term|nape|content=nape {{anchor|hindneck}} }}

{{defn|Also defined: hindneck. The back of the head, behind the {{gli|crown}}. The area between the nape and the {{gli|mantle}} is known as the hindneck.}}

{{Term|nares|content=nares {{anchor|nostril|nostrils}} }}

{{defn|The two holes—circular, oval or slit-like in shape—which lead to the nasal cavities within the bird's skull, and thus to the rest of the respiratory system. In most bird species, the nares are located in the basal third of the upper mandible. Kiwis are a notable exception; their nares are located at the tip of their bills. A handful of species have no external nares. Cormorants and darters have primitive external nares as nestlings, but these close soon after the birds fledge; adults of these species (and gannets and boobies of all ages, which also lack external nostrils) breathe through their mouths. There is typically a septum made of bone or cartilage that separates the two nares, but in some families (including gulls, cranes and New World vultures), the septum is missing. While the nares are uncovered in most species, they are covered with feathers in a few groups of birds, including grouse and ptarmigans, crows and some woodpeckers.}}

{{Term|nasal canthus|content=nasal canthus {{anchor|nasal canthi||canthi|canthus}} }}

{{defn|The area where the eyelids come together at the anterior corner of the eye, on the side of the {{gli|nares}}, as opposed to the {{gli|temporal canthus}}.}}

{{Term|natal down|content=natal down {{anchor|natal-down|natal down feather|natal down feathers|natal-down feathers|neossoptiles|protoptile|protoptiles|mesoptile|mesoptiles}} }}

{{defn|Also, neossoptiles. Also defined: protoptiles; mesoptiles. The layer of {{gli|down}} feathers that cover most birds at some point in their early development. Precocial nestlings are already covered with a layer of down when they hatch, while altricial nestlings develop their down layer within days or weeks of hatching. Megapode hatchlings are the sole exception; they are already covered with contour feathers when they hatch.{{Harvnb|Campbell|Lack|1985|p=470}} The natal down coat is usually lost within a week or two of hatching. There are two different kinds of natal down feathers; protoptiles and mesoptiles.{{cite magazine| issn = 0080-4622| volume=226| issue= 533| pages = 143–188| last = Hosker| first = Anne| title = Studies on the epidermal structures of birds| magazine = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences| date = 1936| jstor = 92253| doi = 10.1098/rstb.1936.0006| bibcode = 1936RSPTB.226..143H| doi-access = free}} The former appears first{{harvnb|Bird|2004|p=281}} and the latter appears second.{{harvnb|Bird|2004|p=277}} Hathchlings born naked or with a diffuse coat of scant natal down feathers are called {{gli|psilopaedic}}, while those born covered with a dense fuzz of natal down are termed {{gli|ptilopaedic}}.{{Harvnb|Gill|1995|p=108}} Compare: {{gli|body down}} and {{gli|powder down}}.}}

File:Nests.svg placement and construction]]

{{Term|nest|content=nest {{anchor|nests|birdnest|bird nest|birdnests|bird nests|burrow|cavity|cup| dormitory|eyries|aeries|mound|pendant|platform|roost|winter|scrape|saucer|plate |sphere|burrows|cavities|cups|dormitories|mounds|pendants|platforms|roosts|winters|scrapes|saucers|plates|spheres|statant|statant cup|adherent cup|hanging}} }}

{{main|Bird nest}}

{{defn|Also, bird nest. Specialized types: burrow; cavity; cup (adherent cup; statant cup); dome; dormitory; eyries (or aeries); hanging; ledge; mound; pendant; platform; roost (or winter-nest); scrape; saucer or plate; and sphere. The spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American robin or Eurasian blackbird, or the elaborately woven hanging nest of the Montezuma oropendola or the village weaver—for some species, a nest is simply a shallow depression made in sand; for others, it is the knot-hole left by a broken branch, a burrow dug into the ground, a chamber drilled into a tree, an enormous rotting pile of vegetation and earth, a shelf made of dried saliva or a mud dome with an entrance tunnel. The smallest bird nests are those of some hummingbirds, tiny cups which can be a mere {{convert|2|cm|in|abbr=on}} across and {{convert|2|–|3|cm|in|abbr=on}} high.{{Harvnb|Campbell|Lack|1985|p=386}} At the other extreme, some nest mounds built by the dusky scrubfowl measure more than {{convert|11|m|ft|abbr=on}} in diameter and stand nearly {{convert|5|m|ft|abbr=on}} tall.{{Harvnb|Campbell|Lack|1985|p=345}} Not all bird species build nests. Some species lay their eggs directly on the ground or rocky ledges, while brood parasites lay theirs in the nests of other birds, letting unwitting "foster parents" do all the work of rearing the young. Although nests are primarily used for breeding, they may also be reused in the non-breeding season for roosting and some species build special dormitory nests or roost nests (or winter-nest) that are used only for roosting.{{cite magazine|title=The nest as a dormitory|last=Skutch |first=Alexander F|magazine=Ibis| volume=103| issue= 1 | pages=50–70 | doi=10.1111/j.1474-919X.1961.tb02420.x| year=1960}} Most birds build a new nest each year, though some refurbish their old nests.{{cite web|last=Gibbon|first=Johnny|publisher=Smithsonian|title=Bird Nests: Variety Is Key For The World's Avian Architects|url=http://smithsonianscience.org/2015/04/bird-nests-variety-is-key-for-avian-architects|date=April 20, 2015|archive-url=https://web.archive.org/web/20170103173244/http://insider.si.edu/2015/04/bird-nests-variety-is-key-for-avian-architects/|archive-date=January 3, 2017|access-date=February 7, 2017|url-status=dead}} The large eyries (or aeries) of some eagles are platform nests that have been used and refurbished for several years. In most species, the female does most or all of the nest construction, though the male often helps.{{Harvnb|Campbell|Lack|1985|p=387}} The nest may form a part of the courtship display, such as in weaver birds.}}

File:Bird blink-edit.jpg]]

{{Term|nictitating membrane|content=nictitating membrane {{anchor|nictitating membranes|nictitating|third eyelid}} }}

{{defn|Also, third eyelid. A transparent or translucent third eyelid that is drawn across the eye for protection, to moisten it while maintaining vision.{{cite magazine|last1=Williams |first1=David L. |date=March 2003 |title=Symblepharon with aberrant protrusion of the nictitating membrane in the snowy owl (Nyctea scandiaca) |magazine=Veterinary Ophthalmology |volume=6 |issue= 1 |pages=11–13 |doi=10.1046/j.1463-5224.2003.00250.x |pmid=12641836 |last2=Flach |first2=E}} The nictitating membrane also covers the eye and acts as a contact lens in many aquatic birds.{{Harvnb|Gill|1995|p=185}} With the exception of pigeons and a few other species, most birds blink only with their nictitating membrane, and when not sleeping, use the eyelids chiefly only when the eye is threatened with some foreign matter.{{Harvnb|Pettingill|1985|page=11}}}}

{{Term|nidicolous|content=nidicolous}}

{{Main|Nidicolous}}

{{defn|Young that remain in their nest after hatching for an extended period of time and thus must be {{gli|dietary classification terms (-vores)|fed}} by their parents. Contrast: {{gli|nidifugous}}.}}

{{Term|nidifugous|content=nidifugous}}

{{Main|Nidifugous}}

{{defn|Young that leave the nest soon after hatching, joining their parents in {{gli|foraging}}. Contrast: {{gli|nidicolous}}.}}

{{Term|non-breeding plumage}}

{{defn|See {{gli|basic plumage}}.}}

{{Term|notch|content=notch {{anchor|notches}} }}

{{Main|Flight feather#Emargination}}

{{defn|A pronounced narrowing at some variable distance along the feather edges at the outermost {{gli|primaries}} of large soaring birds, particularly raptors. Whether these narrowings are called notches or {{gli|emarginations}} depends on the degree of their slope. An emargination is a gradual change, and can be found on either side of the feather. A notch is an abrupt change, and is only found on the wider trailing edge of the remiges. The presence of notches and emarginations creates gaps at the wingtip; air is forced through these gaps, increasing the generation of lift.}}

{{Term|nuptial plumage}}

{{defn|See {{gli|alternate plumage}}.}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|oology|content=oology {{anchor|oologist}} }}

{{Main|oology}}

{{defn|The scientific study of eggs.{{cite book|last=Hauber|first=Mark E.|title=The Book of Eggs: A Life-Size Guide to the Eggs of Six Hundred of the World's Bird Species|url=https://books.google.com/books?id=evQvBAAAQBAJ|date=1 August 2014|publisher=University of Chicago Press|location=Chicago|isbn=978-0-226-05781-1|page=31|access-date=14 June 2018|archive-date=24 February 2024|archive-url=https://web.archive.org/web/20240224051302/https://books.google.com/books?id=evQvBAAAQBAJ|url-status=live}}}}

{{Term|operculum|content=operculum {{anchor|opercula}} }}

{{defn|Plural: opercula. A membraneous, horny or cartilaginous flap covering the {{gli|nares}} of some birds.{{Harvnb|Gill|1995|p=117}}{{cite book |title=The Century Dictionary and Cyclopedia, Vol. 6|first1=William Dwight |last1=Whitney |first2=Benjamin Eli |last2=Smith |year=1911 |publisher=The Century Company |location=New York |page=4123 |lccn=11031934 |url=https://books.google.com/books?id=dhTpAAAAMAAJ&pg=PA4123 }} For example, in diving birds, the operculum keeps water out of the nasal cavity; when the birds dive, the impact force of the water closes the operculum.{{cite magazine |title=Organisms as Functional Machines: A Connectivity Explanation |first=Walter J. |last=Bock |magazine=American Zoologist |year=1989 |jstor=3883510 |volume=29 |issue= 3 |pages=1119–1132 |doi=10.1093/icb/29.3.1119|doi-access=free }}}}

{{Term|overbrooding|content=overbrooding {{anchor|over-brooding|over brooding|overbrood|over-brood|over brood|overbroods|over-broods|over broods|overbrooded}} }}

{{defn|The not uncommon phenomenon of birds continuing to {{gli|brood}} eggs that are not viable and will not hatch, sometimes for lengthy periods of time beyond the normal incubation period.{{Harvnb|Weaver|1981|p=83}}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

File:Bird.parts.jpg]]

{{Glossary}}

{{Term|passerine|content=passerine {{anchor|passerines|perching bird|perching birds}} }}

{{defn|Also, perching bird. Any bird of the order Passeriformes, which includes more than half of all bird species. A notable feature of passerines compared to other orders of Aves is the arrangement of their toes—three pointing forward and one back—which facilitates perching. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders, with over 5,000 identified species.{{cite magazine|last1=Mayr|first1=Ernst|url=http://sora.unm.edu/sites/default/files/journals/auk/v063n01/p0064-p0069.pdf|title=The Number of Species of Birds|magazine=The Auk|volume=63|issue=1|pages=64–69|year=1946|doi=10.2307/4079907|jstor=4079907|access-date=2017-01-21|archive-date=2016-03-04|archive-url=https://web.archive.org/web/20160304063910/http://sora.unm.edu/sites/default/files/journals/auk/v063n01/p0064-p0069.pdf|url-status=live}} The order has roughly twice as many species as Rodentia, the largest order of mammals. There are more than 110 families of passerine birds, the second-most of any tetrapods (after Squamata, the scaled reptiles).}}

{{Term|pectinate claw|content=pectinate claw {{anchor|pectinate claws|feather comb}} }}

{{defn|Also, feather comb.{{sfn|Lovette|Fitzpatrick|2016|p=181}} A claw on the middle toe of some birds, such as nightjars, herons, and barn owls,{{cite book|last=Kennedy|first=Adam Scott|title=Birds of the Serengeti and Ngorongoro Conservation Area|url=https://books.google.com/books?id=gmmYDwAAQBAJ&pg=PA198|year=2014|publisher=Princeton University Press|isbn=978-0-691-15910-2|page=198|access-date=2023-03-19|archive-date=2023-05-28|archive-url=https://web.archive.org/web/20230528143743/https://books.google.com/books?id=gmmYDwAAQBAJ&pg=PA198|url-status=live}} with a serrated edge. The degree of serration varies from fine to coarse, depending on the species. It is used in {{gli|preening}}, functioning similar to a comb. Some birds may use it to straighten the {{gli|rictal bristles}}.{{Harvnb|Elphick|2016|p=77}} It may also play an important role in parasite removal. For example, a study of barn owls found a significant correlation between the number of serrated teeth on an individual's pectinate claw, and the prevalence of its lice infestation.{{cite magazine|last1=Bush|first1=Sarah E.|last2=Villa|first2=Scott M.|last3=Boves|first3=Than J.|last4=Brewer|first4=Dallas|last5=Belthoff|first5=James R.|title=Influence of bill and foot morphology on the ectoparasites of barn owls| magazine=Journal of Parasitology|volume=98|issue=2|date=April 1, 2012|pages=256–261|url=https://doi.org/10.1645/GE-2888.1|doi=10.1645/GE-2888.1|pmid=22010835}}}}

{{Term|pectoral tuft|content=pectoral tuft {{anchor|pectoral tufts|pectoral-tuft|pectoral-tufts}} }}

{{defn|Elongated {{gli|feathers}}, often brightly coloured, which arise from the sides of the {{gli|chest}} of some species of birds, including many sunbirds, spiderhunters and flowerpeckers.{{sfn|Cheke|Mann|Allen|2001|p=15}} They are typically hidden when the wing is folded on a perched bird, but prominent during courtship and territorial displays.{{sfn|Cheke|Mann|Allen|2001|p=23}} In sunbirds and spiderhunters, these tufts may be yellow, red or orange; in flowerpeckers, they are usually white.{{sfn|Cheke|Mann|Allen|2001|p=15}} The size of the tufts in some species can be an indicator of a male's fitness and status; males with larger tufts defend larger territories and have higher reproductive success.{{cite journal |first1=Matthew R. |last1=Evans |first2=B.J. |last2=Hatchwell |name-list-style=amp |title=An experimental study of male adornment in the scarlet-tufted malachite sunbird: I. The role of pectoral tufts in territorial defence |journal=Behavioral Ecology and Sociobiology |date=1992 |volume=29 |issue=6 |pages=413–419 |doi=10.1007/BF00170171 |jstor=4600642 |bibcode=1992BEcoS..29..413E |url=https://www.researchgate.net/publication/227254273}}}}

{{Term|pennaceous feather|content=pennaceous feather {{anchor|pennaceous feathers|contour feather|contour feathers|pennaceous|contour}} }}

{{Main|Pennaceous feather}}

{{defn|Also, contour feather. A type of {{gli|feather}} present in most modern birds and in some other species of maniraptoriform dinosaurs.{{Cite web|title=GEOL 204 The Fossil Record: Feathered Dragons: The Origins of Birds and of Avian Flight|url=http://www.geol.umd.edu/~tholtz/G204/lectures/204birds.html|publisher=Department of Geology at the University of Maryland|archive-url=https://web.archive.org/web/20170317235550/http://www.geol.umd.edu/~tholtz/G204/lectures/204birds.html|archive-date=March 17, 2017|access-date=January 29, 2017|url-status=dead}} Pennaceous feathers have a stalk called a {{gli|quill}}, with the basal part called a {{gli|calamus}}, that is embedded in the skin exclusively at {{gli|pterylae}} (feather tracts).{{Harvnb|Chandler|1916|p=250}} The calamus is hollow and has pith formed from the dry remains of the feather pulp. The calamus stretches between two openings—at its base is the {{gli|inferior umbilicus}} and at its distal end is the {{gli|superior umbilicus}}; the {{gli|rachis}} of the main stem, hosting the {{gli|vanes}}, continues above it.{{Cite web|last=Ritchison|first=Gary|title=Ornithology (Bio 554/754): Feather Evolution|url=http://people.eku.edu/ritchisong/feather_evolution.htm|publisher=Department of Biological Sciences, Eastern Kentucky University|access-date=January 16, 2017|archive-url=https://web.archive.org/web/20170225102837/http://people.eku.edu/ritchisong/feather_evolution.htm|archive-date=February 25, 2017|url-status=dead}} The rachides of contour feathers have an umbilical groove on their underside, with the vanes or vexilla, spreading to either side. The vanes comprise many flattened {{gli|barbs}}, that are connected to one another by {{gli|hooklets}} that are anchored into flanges on {{gli|proximal barbules}} on neighboring barbs. Some specialized feathers are considered "modified" contour feathers, such as {{gli|ear coverts}} and bird eyelashes called {{gli|rictal bristles}}. Contrast: {{gli|down feathers|plumulaceous (down) feathers}} and {{gli|filoplumes}}.}}

{{Term|philopatry|content=philopatry {{anchor|philopatric}} }}

{{defn|The habit of a bird returning to the area it first bred.{{harvnb|Elphick|2016|p=136}}}}

{{Term|pigeon milk}}

{{defn|The term for {{gli|crop milk}} when found among all pigeons and doves.}}

{{Term|pileum|content=pileum {{anchor|pileum of the head}} }}

{{defn|As defined in the treatise Manual of Ornithology: Avian Structure and Function, the "entire top of the head, including the {{gli|forehead}}, {{gli|crown}} and occipital regions."{{Harvnb|Proctor|Lynch|1998|p=64}}}}

Image:Wellensittich01.jpg with {{gli|pin feathers}} showing on its breast.]]

{{Term|pin feather|content=pin feather {{anchor|pin feathers|blood feather|blood feathers}} }}

{{Main|Pin feather}}

{{defn|Also, blood feather. A developing {{gli|feather}} encased in a {{gli|feather sheath}} that, unlike a fully developed feather, has a blood supply flowing through it. As such, damage to pin feathers can cause significant bleeding. Pin feathers may be the first feather growth during a bird's infancy, or those growing during {{gli|moulting}} at any stage of a bird's life. As pin feather growth progresses, the blood supply is concentrated only in the base of the {{gli|calamus}}. Pin feathers begin to develop after the feather bud invaginates a cylinder of epidermal tissue around the base of the dermal papilla, forming the feather follicle. At the base of the feather follicle, epithelial cells proliferate to grow the epidermal collar or cylinder. As the epidermal cylinder extends through dermis, it differentiates into a protective peripheral sheath, longitudinal barb ridges and growth plates. Over time these barb ridges grow in a helical manner, branching to create {{gli|barbs}} and {{gli|barbules}}, and fusing to form the central feather shaft. Moreover, the barb plate further differentiates into {{gli|hooklets}} and {{gli|cilia}}, while the marginal and axial plate die to form the intervening space within the feather structure.{{Harvnb|Proctor|Lynch|1998|p=86}}{{cite book|last=Athan|first=Mattie Sue |title=Guide to the Quaker Parrot|url=https://books.google.com/books?id=wB6tG1E6O-QC&pg=PA57|year=2008|publisher=Barron's Educational Series|isbn=978-0-7641-3668-9|page=57}}{{Harvnb|Pettingill|1985|pp=41–42}}}}

{{Term|pinioning|content=pinioning {{anchor|pinion joint|pinion joints}} }}

{{defn|Also defined: pinion joint. The act of surgically removing one {{gli|pinion}} joint—the joint of a bird's wing farthest from the body—thereby stopping the growth of the {{gli|primary feathers}}, to prevent flight. The animal welfare impact of pinioning is subject to increasing debate. For example, it is known that the operation, which is often performed without pain relief, is just as painful in young birds as in mature birds, if not more so. Evidence also suggests that pinioning may cause a phantom limb syndrome similar to what is observed in human amputees.{{cite book|author1=Ian J. h. Duncan|author2=Penny Hawkins|title=The Welfare of Domestic Fowl and Other Captive Birds|url=https://books.google.com/books?id=mhnYLcXA6MYC&pg=PA84|year=2010|publisher=Springer|isbn=978-90-481-3649-0|pages=84–85}}}}

{{Term|pinions|content=pinions {{anchor|pinion}} }}

{{defn|The outermost {{gli|primaries}}—those connected to the phalanges.{{cite book|last=Hudson|first=W.H. |title=Harmsworth Natural History: A Complete Survey of the Animal Kingdom|url=https://books.google.com/books?id=zvxGAQAAMAAJ|year=1910|publisher=Carmelite House|location=London|page=926}}}}

File:Guiraca caeruleaAAP086CB.jpg, from top to bottom, between a breeding male ({{gli|alternate plumage}}), a non-breeding male ({{gli|basic plumage}}), a female and a related indigo bunting]]

{{Term|plumage|content=plumage {{anchor|plumages}} }}

{{Main|Plumage}}

{{defn|Plumage ({{Langx|la|plūma}} 'feather') refers both to the layer of {{gli|feathers}} that cover a bird and the pattern, colour and arrangement of those feathers.{{Cite OED|Plumage}} The pattern and colours of plumage differ between species and subspecies, often vary with age and may vary sharply between males and females of the same species that exhibit {{gli|sexual dimorphism}}. Within species there can be different {{gli|colour morphs}}. Despite the great variance, as broad observations: 1) among many bird species adult males are more brightly coloured than are females, especially when in {{gli|alternate plumage|alternate or nuptial plumage}}, as opposed to {{gli|basic plumage|basic or winter plumage}}; 2) when male birds undergo the {{gli|prebasic moult}} and attain their non-breeding plumage, they much more closely resemble females; and 3) the plumage of juvenile birds (of both sexes) tends to be relatively dull and inconspicuous and typically resembles that of adult females.{{Harvnb|Pettingill|1985|p=194}}}}

{{Term|plumology|content=plumology {{anchor|plumage science}} }}

{{defn|Also, plumage science. The name for the science that is associated with the study of {{gli|feathers}}.{{cite web|last1=Rosenberg|first1=Daniel K.|last2=Geist|first2=Dennis|last3=Harpp|first3=Karen|title=Galapagos plumology|url=http://www.darwinfoundation.org/datazone/galapagos-research/article/galapagos-plumology/|website=darwinfoundation.org|publisher=Charles Darwin Collections Database by the Charles Darwin Foundation|archive-url=https://web.archive.org/web/20160317093057/http://www.darwinfoundation.org/datazone/media/pdf/59/NG_59_1998_Harpp%26Geist_Galapagos_plumology.pdf|archive-date=March 17, 2016|access-date=January 29, 2017|issn=1390-2830|url-status=dead}}{{cite book|last1=Eichhorn|first1=hrsg. von Manfred|title=Langenscheidt Fachwörterbuch Biologie Englisch: englisch – deutsch, deutsch – englisch|date=2005|publisher=Langenscheidt|location=Berlin [u.a.]|isbn=978-3-86117-228-4|page=537|edition=1. Aufl.|url=https://books.google.com/books?id=KRJfNmHhIpUC&pg=PA537}}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }}}}

{{Term|podotheca|content=podotheca {{anchor|foot sheath|scutellate|boot|booted|reticulate|boots}} }}

{{defn|Also, foot sheath. Also defined: boot; reticulate; scutellate; booted. The skin that covers the bare feet and legs. It usually consists of many small scales, called {{gli|scutes}}. This type of podotheca is described as being scutellate. When there are no scutes, and the podotheca is a smooth sheath, it is called a boot, and those with podotheca like this are called booted. The podotheca may also be reticulated with small and irregularly raised plates. This arrangement is considered to be reticulate.{{Harvnb|Elphick|2016|p=33}}}}

{{Term|powder down|content=powder down {{anchor|powder-down|powder-down feather|powder-down feathers|powder down feather|powder down feathers|pulviplumes|pulviplume|feather dust}} }}

{{defn|Also, pulviplumes; feather dust. A special type of {{gli|down}} that occurs in a few groups of apparently unrelated birds. In some species, the tips of the {{gli|barbules}} on powder down feathers disintegrate, forming fine particles of keratin, which appear as a powder, or feather dust, among the feathers. These feathers grow continuously and are not moulted.{{cite book |title=Home Study Course in Bird Biology, second edition |publisher=Cornell Laboratory of Ornithology |year=2003 |editor1-last=Podulka |editor1-first=Sandy |editor2-last=Rohrbaugh |editor2-first=Ronald W. |editor3-last=Bonney |editor3-first=Rick |page=55 (Glossary)}} In other species, the powder grains come from cells that surround the barbules of growing feathers.{{harvnb|Campbell|Lack|1985|p=208}} These specialized feathers are typically scattered among ordinary down feathers, though in some species, they occur in clusters. All parrots have powder down, with some species (including the mealy parrot) producing copious amounts.{{cite book |title=Parrots: A Guide to the Parrots of the World |first1=Tony |last1=Juniper |first2=Mike |last2=Parr |year=2003 |publisher=Christopher Helm |location=London |isbn=978-0-7136-6933-6 |page=17}} It is also found in tinamous and herons. The dust produced from powder down feathers is a known allergen in humans.{{cite book |title=Allergic to Pets?: The Breakthrough Guide to Living with the Animals You Love |first=Shirlee |last=Kalstone |publisher=Bantam Dell |location=New York, NY |year=2006 |pages=[https://archive.org/details/isbn_9780553383676/page/34 34–35] |isbn=978-0-553-38367-6 |url=https://archive.org/details/isbn_9780553383676/page/34 }} Compare: {{gli|body down}} & {{gli|natal down}}.}}

{{Term|postjuvenal moult}}

{{defn|See {{gli|prebasic moult}}.}}

{{Term|postnuptial moult}}

{{defn|See {{gli|prebasic moult}}.}}

{{Term|prealternate moult|content=prealternate moult {{anchor|prealternate moults|pre-alternate moult|pre-alternate moults|prenuptial moult|pre-nuptial moult|prenuptial moults|pre-nuptial moults}} }}

{{defn|Also, prenuptial moult (sp. variation: in the U.S., sometimes molt). The {{gli|moult}} before the breeding season that most birds undergo, during which parts of the {{gli|basic plumage}} are shed and {{gli|nuptial plumage}} is grown. "Prealternate moult" is used in {{gli|Humphrey–Parkes terminology}}, and "prenuptial moult" is the traditional term. In either system of nomenclature, in juveniles this type of moult is numbered, 1st, 2nd, 3rd (etc.), until the {{gli|definitive plumage}} is attained, after which the numbering is dropped.{{Harvnb|Lovette|Fitzpatrick|2016|p=126}} Unlike the {{gli|prebasic moult}}, in the prealternate moult the major {{gli|flight feathers}} and {{gli|primary coverts}} are not replaced in most species, and the feathers involved typically are "only head and body feathers, {{gli|wing coverts}} and sometimes {{gli|tertials}} and {{gli|rectrices}}".{{cite book|last1=Howell|first1=Steve N. G.|last2=Lewington|first2=Ian|last3=Russell|first3=Will|title=Rare Birds of North America|url=https://books.google.com/books?id=-YqGAAAAQBAJ&pg=PA34|date=February 16, 2014|publisher=Princeton University Press|isbn=978-1-4008-4807-2|page=34}}}}

{{Term|prebasic moult|content=prebasic moult {{anchor|prebasic moults|pre-basic moult|pre-basic moults|postnuptial moult|post-nuptial moult|postnuptial moults|post-nuptial moults|postjuvenal moult|post-juvenal moult|postjuvenal moults|post-juvenal moults|prebasic molt|prebasic molts|pre-basic molt|pre-basic molts|postnuptial molt|post-nuptial molt|postnuptial molts|post-nuptial molts|postjuvenal molt|post-juvenal molt|postjuvenal molts|post-juvenal molts}} }}

{{defn|Also, postnuptial moult (sp. variation: in the U.S., sometimes molt). Also defined: postjuvenal moult. The {{gli|moult}} after the breeding season that most birds undergo, during which {{gli|nuptial plumage}} is shed and {{gli|basic plumage|basic or winter plumage}} is grown. In {{gli|Humphrey–Parkes terminology}}, prebasic moults in juveniles, prior to attaining {{gli|definitive plumage}}, are numbered the 1st, 2nd, 3rd (etc.) prebasic moult. In traditional terminology, the first is called the postjuvenal moult, and thereafter the 1st, 2nd, 3rd (etc.) postnuptial moult. In both nomenclature systems, after definitive plumage is reached, the numbering is dropped.}}

{{Term|precocial|content=precocial {{anchor|semi-precocial|semiprecocial|semi precocial|altricial-precocial spectrum}} }}

{{Main|Precocial}}

{{defn|Also defined: semi-precocial; altricial-precocial spectrum. Young that, at hatching, have their eyes open; are covered in {{gli|down feathers}} ({{gli|ptilopaedic}}); are homeothermic; and are able to leave the nest soon after hatching and join their parents in {{gli|foraging}} activities ({{gli|nidifugous}}). The contrasting state is {{gli|altricial}} young, which are born "helpless"—more or less naked, blind, ectothermic and unable to leave the nest.{{cite book|last=Johnston|first=Richard|title=Current Ornithology|url=https://books.google.com/books?id=riYBCAAAQBAJ&pg=PA34|year=2013|publisher=Springer Science & Business Media|isbn=978-1-4615-6781-3|page=34}} The young of many bird species do not precisely fit into either the precocial or altricial category, having some aspects of each and thus fall somewhere on an altricial-precocial spectrum. A defined intermediate state is termed semi-precocial, typified by young born covered in down and with open eyes; that are usually able to walk shortly after hatching; but which remain mostly confined to the nest, relying on their parents for food ({{gli|nidicolous}}).{{cite book|last=Khanna|first=D.R.|title=Biology of Birds|url=https://books.google.com/books?id=fDblIChi7KwC&pg=PA109|year=2005|publisher=Discovery Publishing House|isbn=978-81-7141-933-3|page=109}}}}

File:Passer domesticus bathing in water, Anas platyrhynchos in background.ogv cleans itself in moving water while a mallard {{gli|preens}} in the background.]]

{{Term|preening|content=preening {{anchor|groom|preen|preens}} }}

{{Main|Preening}}

{{defn|Also, grooming. {{gli|Feathers}} require maintenance and birds preen or groom them daily, spending an average of around 9% of their daily time on this activity.{{cite magazine|last=Walther|first=Bruno A.|year=2005|title=Elaborate ornaments are costly to maintain: evidence for high maintenance handicaps|magazine=Behavioral Ecology|volume=16|issue= 1|pages=89–95|doi=10.1093/beheco/arh135|doi-access=free}} The {{gli|bill}} is used to brush away foreign particles and to apply waxy secretions from the uropygial gland; these secretions protect the feathers' flexibility and act as an antimicrobial agent, inhibiting the growth of feather-degrading bacteria.{{cite magazine|last1=Shawkey|first1=Matthew D.|year=2003|title=Chemical warfare? Effects of uropygial oil on feather-degrading bacteria |magazine=Journal of Avian Biology|volume=34|issue= 4|pages=345–49|doi=10.1111/j.0908-8857.2003.03193.x|last2=Pillai |first2=Shreekumar R.|last3=Hill|first3=Geoffrey E.}} This may be supplemented with the secretions of formic acid from ants, which birds receive through a behaviour known as {{gli|anting}}, to remove feather parasites.{{cite magazine|last=Ehrlich|first=Paul R.|year=1986|title=The Adaptive Significance of Anting|magazine=The Auk|volume=103|issue= 4|page=835|url=http://sora.unm.edu/sites/default/files/journals/auk/v103n04/p0835-p0835.pdf|archive-url=https://web.archive.org/web/20160305202116/http://sora.unm.edu/sites/default/files/journals/auk/v103n04/p0835-p0835.pdf|archive-date=March 5, 2016|url-status=dead|df=dmy}}}}

{{Term|prenuptial moult}}

{{defn|See {{gli|prealternate moult}}.}}

{{Term|primaries|content=primaries {{anchor|primary feather|primary feathers|primary|primary remiges|primary remex}} }}

{{Main|Flight feather#Primaries}}

{{defn|Also, primary feathers; primary remiges. A type of {{gli|remex}} flight feather, they are connected to the manus (the bird's "hand", composed of carpometacarpus and phalanges); these are the longest and narrowest of the remiges (particularly those attached to the phalanges), and they can be individually rotated. These feathers are especially important for flapping flight, as they are the principal source of thrust, moving the bird forward through the air. Most thrust is generated on the downstroke of flapping flight. However, on the upstroke (when the bird often draws its wing in close to its body), the primaries are separated and rotated, reducing air resistance while still helping to provide some thrust.{{Harvnb|Ehrlich|Dobkin|Wheye|Pimm|1994|p=219}} The flexibility of the remiges on the wingtips of large soaring birds also allows for the spreading of those feathers, which helps to reduce the creation of wingtip vortices, thereby reducing drag.{{Harvnb|Ehrlich|Dobkin|Wheye|Pimm|1994|p=79}} In most flighted birds, some of the distal {{gli|barbules}} on the inner {{gli|vane}} of these feathers, called {{gli|friction barbules}}, are specialized, with large lobular barbicels that are thought to help grip and prevent slippage of overlying feathers.{{cite magazine|last1=Muller|first1=Werner|last2=Patone|first2=Giannino |year=1998|title=Air transmissivity of feathers|magazine=Journal of Experimental Biology|volume=201|pages=2591–2599|url=http://jeb.biologists.org/cgi/reprint/201/18/2591.pdf|pmid=9716511|issue= 18}} Species vary in the number of primaries they possess. The number in non-passerines generally varies between 9 and 11,{{cite book|last1=Jenni|first1=Lukas|last2=Winkler|first2= Raffael|title=Moult and Ageing of European Passerines|year=1994|publisher=Academic Press|location=London |isbn=978-0-12-384150-6|page=7}} but grebes, storks and flamingos have 12 and ostriches have 16.{{Harvnb|del Hoyo|Elliott|Sargatal|1992|p=37}} While most modern passerines have ten primaries, some have only nine. Those with nine are missing the most distal primary, sometimes called the {{gli|remicle}}, which is typically very small and sometimes rudimentary in passerines.}}

{{Term|primary projection|content=primary projection {{anchor|primary projections|primary extension|primary extensions}} }}

{{Main|Flight feather#Primary extension}}

{{defn|Also, primary extension. The distance that a bird's longest primaries extend beyond its longest secondaries (or {{gli|tertials}}) when its wings are folded.{{cite book |last=Kaufman |first=Kenn |title=Advanced Birding |publisher=Houghton Mifflin |location=Boston |year=1990 |isbn=978-0-395-53376-5 |pages=[https://archive.org/details/fieldguidetoadva00kauf/page/186 186] |url=https://archive.org/details/fieldguidetoadva00kauf/page/186 }} As with {{gli|wing formulae}}, this measurement is useful for distinguishing between similarly plumaged birds; however, unlike wing formulae, it is not necessary to have the bird in-hand to make the measurement. Rather, this is a useful relative measurement—some species have long primary extensions, while others have shorter ones. Among the Empidonax flycatchers of the Americas, for example, the dusky flycatcher has a much shorter primary extension than does the very similarly plumaged Hammond's flycatcher. Europe's common skylark has a long primary projection, while that of the near-lookalike Oriental skylark is very short.{{Cite book |last1=Svensson |first1=Lars |last2=Grant|first2=Peter J. |title=Collins Bird Guide: The Most Complete Field Guide to the Birds of Britain and Europe |year=1999 |publisher=HarperCollins |location=London |isbn=978-0-00-219728-1 |pages=231}} As a general rule, species which are long distance migrants will have longer primary projection than similar species which do not migrate or migrate shorter distances.{{cite book|last=Christie|first=Thomas Alerstam; translated by David A.|title=Bird migration|date=1993|publisher=Cambridge University Press|location=Cambridge [England]|isbn=978-0-521-44822-2|pages=253}}}}

{{Term|proventriculus|content=proventriculus {{anchor|proventriculi}} }}

{{Main|proventriculus}}

{{defn|The first part of the stomach of a bird. The inside is lined with gastric glands, which secrete gastric juices containing enzymes and hydrochloric acid. In some birds, such as petrels, the proventriculus is expandable. This allows these birds to either digest their food later or carry it back to their young. The proventriculus leads into the {{gli|gizzard}}.{{Harvnb|Elphick|2016|p=49}}}}

{{Term|psilopaedic}}

{{defn|Young that are born naked or with only a small amount of {{gli|down}} feather coverage, as opposed to birds that are {{gli|ptilopaedic}}.}}

{{Term|pterylae|content=pterylae {{anchor|pterylya|feather tracts|feather tract|tracts|tract}} }}

{{defn|Singular: pteryla. The feather tracts of a bird's skin from which the {{gli|contour feathers}} grow, often in sharply defined and dense clusters—as opposed to the {{gli|apterylae}}. See related: {{gli|pterylosis}}.}}

File:PasserinePterylosis (cropped).jpg

{{Term|pterylosis|content=pterylosis {{anchor|pterylya}} }}

{{defn|Also, pterylography. The arrangement of feather tracts, as seen in a bird's {{gli|pterylae}} and {{gli|apterylae}}, which varies across bird families and has been used in the past as a means for determining the evolutionary relationships among them.{{cite magazine|magazine=Journal of Ornithology| title= Do nine-primaried passerines have nine or ten primary feathers? The evolution of a concept| volume=146| issue= 2| pages=121–126| year=2005|last1=Hall|first1=K.|last2=Susanna|first2=S. |doi=10.1007/s10336-004-0070-5| s2cid= 36055848}}{{cite magazine|last= Pycraft| first=W. P.|year=1895|title=On the pterylography of the hoatzin (Opisthocomus cristatus)| magazine= Ibis| volume=37| pages= 345–373|doi=10.1111/j.1474-919X.1895.tb06744.x|issue= 3}}}}

{{Term|ptilopaedic}}

{{defn|Young that are born covered with {{gli|down}} feathers, as opposed to birds that are {{gli|psilopaedic}}.}}

{{Term|pupil|content=pupil {{anchor|pupils}} }}

{{defn|The dark disk at the centre of a bird's eye through which light enters, surrounded by the coloured outer ring of the {{gli|iris}}.{{cite book|last1=Baird|first1=Spencer Fullerton|last2=Brewer|first2=Thomas Mayo|last3=Ridgway|first3=Robert|title=A History of North American Birds|url=https://books.google.com/books?id=PF8MAQAAIAAJ&pg=PA554|year=1874|publisher=Little, Brown|page=554}}}}

{{Term|pygostyle|content=pygostyle {{anchor|pygostylea|tailbone|tailkbones|tail bone|tail bones}} }}

{{defn|Also, tail bone. A skeletal formation, plowshare-shaped in birds, in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the {{gli|rectrices}} attach to these. The pygostyle is the main component of the {{gli|uropygium}}.{{cite book|last=Chatterjee|first=Sankar|title=The Rise of Birds: 225 Million Years of Evolution|url=https://books.google.com/books?id=V-okBwAAQBAJ&pg=PA114|year=2015|publisher=JHU Press|isbn=978-1-4214-1614-4|pages=114–115}}{{Harvnb|Lovette|Fitzpatrick|2016|p=177}}}}

{{Term|pullus|content=pullus {{anchor|pullus|pulli}} }}

{{defn|(plural pulli) A chick in the downy phase of development.{{cite web |title=Definition of Pullus |url=https://www.merriam-webster.com/dictionary/pullus |website=Merriam-Webster |access-date=30 June 2024 }}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|quartering}}

{{defn|A hunting technique where a bird flies slowly just above the water or ground in open habitats.{{Harvnb|Elphick|2016|p=117}}}}

{{Term|quill|content=quill {{anchor|quills|main stem|scapus|primary quill}} }}

{{defn|Also, primary quill; main stem; scapus. The main stem of a feather from which all structures branch, if any. The proximal portion is called the {{gli|calamus|calamus or shaft}}, and the distal portion is called the {{gli|rachis}}, with the demarcation point between them usually defined as the {{gli|superior umbilicus}}. However, some authorities define quill very differently, using it as a synonym for the calamus.{{Harvnb|Gill|1995|p=80}} The contradiction between sources on this issue is quite sharp. For example, in Asa Chandler's well known treatise, A study of the structure of feathers, with reference to their taxonomic significance, "quill" is defined at page 250 as: "The main stem of a feather, including both shaft and calamus (Coues, 1884; Beebe, 1906, et al.). Synonyms: main stem (Nitzsche, 1867)". By contrast, in Frank B. Gill's well known treatise, Ornithology, he writes at page 80: "The hollow base of the shaft—the calamus, or quill—anchors the feather in a follicle below the surface of the skin". In this glossary, the former definition will be used, treating quill as denoting the "main stem" of a feather.}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|rachis|content=rachis {{anchor|quill|quills|rachises|rachides|medulla|medullae|shaft|shafts|rhachis|rhachises|rhachides}} }}

{{defn|Plural: rachises; rachides. Also, shaft. Variable sp.: rhachis.{{cite magazine|last=Lillie|first=Frank R.|title=On the Development of Feathers|date=November 1941|page=247|magazine=Biological Reviews|volume=17|issue= 3|doi=10.1111/j.1469-185X.1942.tb00439.x|s2cid=84592534}} Also defined: medulla. The distal or upper section of the {{gli|quill}}, above the {{gli|calamus}}, stretching from the {{gli|superior umbilicus}} to the tip of the feather, upon which the {{gli|vanes}} and other structures are anchored. The rachis is flexible from side to side toward the blade projections, but far stiffer inward and outward from the bird's body. This arrangement aids in allowing the {{gli|flight feather}} to act as a "resilient airfoil".{{Harvnb|Pettingill|1985|pages=29–32}} The rachis is composed of two layers: a pithy, opaque material makes up the core layer called the medulla, which is covered by a thin and translucent outer layer or cortex that features longitudinal internal ridges on the dorsal side and external ridges on the ventral side.}}

{{Term|rectrices|content=rectrices {{anchor|rectrice|rectrix}} }}

{{Main|Flight feather#Rectrices}}

{{defn|Singular: rectrix. From the Latin for 'helmsman', they are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the tail of a bird, which help it to brake and steer in flight. They lie in a single horizontal row on the rear margin of the anatomic tail. The vast majority of species having six pairs. They are absent in grebes and some ratites, and greatly reduced in size in penguins.{{Harvnb|del Hoyo|Elliott|Sargatal|1992|pp=84–85, 91, 104}}{{Harvnb|del Hoyo|Elliott|Sargatal|1992|p=141}} Many grouse species have more than 12 rectrices. Some species (including ruffed grouse, hazel grouse and common snipe) have a number that varies among individuals.{{Cite book |last1=Madge |first1=Steve |last2=McGowan|first2=Phil|title=Pheasants, Partridges & Grouse |year=2002 |publisher=Christopher Helm |location=London |isbn=978-0-7136-3966-7 |pages=375}} Domestic pigeons have a highly variable number, due to centuries of selective breeding.{{Harvnb|del Hoyo|Elliott|Sargatal|1992|p=105}}}}

{{Term|remiges|content=remiges {{anchor|remige|remex|postpatagium}} }}

{{Main|Flight feather#Remiges}}

{{defn|Singular: remex. Also defined: postpatagium. From the Latin for 'oarsman', they are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings of a bird. They are located on the posterior side of the wing. Ligaments attach the long calami firmly to the wing bones, and a thick, strong band of tendinous tissue known as the postpatagium helps to hold and support the remiges in place.{{cite book |title=Home Study Course in Bird Biology, Second Edition |editor-last1=Podulka|editor-first1=Sandy|editor-last2=Rohrbaugh|editor-first2=Ronald W.|editor-last3=Bonney|editor-first3=Rick|year=2003 |publisher=Cornell Lab of Ornithology|location=Ithaca, New York |page=1.11}} Corresponding remiges on individual birds are symmetrical between the two wings, matching to a large extent in size and shape (except in the case of mutation or damage), though not necessarily in pattern.{{Harvnb|Trail|2001|p=8}}{{cite magazine|last1=Moller|first1=Anders Pape|last2=Hoglund|first2=Jacob |year=1991|title=Patterns of Fluctuating Asymmetry in Avian Feather Ornaments: Implications for Models of Sexual Selection|magazine=Proceedings: Biological Sciences|volume=245|issue= 1312|pages=1–5|doi=10.1098/rspb.1991.0080|bibcode=1991RSPSB.245....1P|s2cid=84991514}} They are given different names depending on their position along the wing.}}

File:Sylviaatricapillamap2.pngs—corresponding to the example use of {{nowrap|"{{gli|resident}}"}} in its definition at the left]]

{{Term|remicle|content=remicle {{anchor|little remex}} }}

{{defn|Also, little remex. The most distal {{gli|primary feather}}. The remicle is very small and usually non-functional—interpreted by Christian Ludwig Nitzsch as "an aborted first primary". It was named by Richard S. Wray in 1887, who similarly thought of it as "representing an originally functional primary".{{cite magazine|magazine=The Condor|volume=65|issue=6|date=November–December 1963|last1=Stresemann|first1=Erwin|author-link=Erwin Stresemann|url=https://sora.unm.edu/sites/default/files/journals/condor/v065n06/p0449-p0459.pdf|title=Variations in the Number of Primaries|pages=449–459|doi=10.2307/1365506|jstor=1365506|access-date=2017-02-05|archive-date=2021-10-19|archive-url=https://web.archive.org/web/20211019024247/https://sora.unm.edu/sites/default/files/journals/condor/v065n06/p0449-p0459.pdf|url-status=live}}}}

{{Term|resident|content=resident {{anchor|residents|permanent resident|permanent residents|sedentary}} }}

{{defn|Also, permanent resident; sedentary. Non-migratory; a bird that stays year-round and breeds in one geographic area or habitat.{{Harvnb|Lovette|Fitzpatrick|2016|p=458}} Both permanent resident and sedentary are common with the defined usage. Although resident is used in this sense, it is often used as well for birds that are "migratory in part of their breeding range and resident elsewhere",{{cite magazine|last1=Terrill|first1=Scott B.|last2=Abel|first2=Kenneth P.|title=Bird Migration Terminology|magazine=The Auk|date=January 1988|volume=105|url=https://sora.unm.edu/sites/default/files/journals/auk/v105n01/p0205-p0206.pdf|page=206|doi=10.1093/auk/105.1.205|access-date=2017-03-19|archive-date=2021-10-19|archive-url=https://web.archive.org/web/20211019030805/https://sora.unm.edu/sites/default/files/journals/auk/v105n01/p0205-p0206.pdf|url-status=live}} e.g., "Eurasian blackcaps (Sylvia atricapilla) are summer visitors to Eastern and Northern Europe, resident in Western Europe and winter visitors to Africa."}}

File:BarbetRictalBristle.jpg]]

{{Term|rictal bristles|content=rictal bristles {{anchor|rictal bristle|bristle|bristles|bristle feather|bristle feathers|rictal bristle feather|rictal bristle feathers|eyelashes| eye lashes}} }}

{{defn|Also, bristles; bristle feathers; eyelashes. Stiff, hair-like, tapering feathers with a large {{gli|rachis}} but few {{gli|barbs}} found around the eyes and the base of the {{gli|beak}} of some bird species.{{cite magazine |title=The Role of Avian Rictal Bristles |first=Roger J |last=Lederer |url=http://sora.unm.edu/sites/default/files/journals/wilson/v084n02/p0193-p0197.pdf |magazine=The Wilson Bulletin |volume=84 |pages=193–197 |issue=2 |access-date=2017-01-20 |archive-date=2014-02-04 |archive-url=https://web.archive.org/web/20140204025111/http://sora.unm.edu/sites/default/files/journals/wilson/v084n02/p0193-p0197.pdf |url-status=live }} They are common among insectivorous birds, but are also found in some non-insectivorous species.{{cite magazine |title=Rictal Bristle Function in Willow Flycatcher |first1=Michael R. |last1=Conover |first2=Don E. |last2=Miller |magazine=The Condor |volume=82 |issue=4 |pages=469–471 |date=November 1980 |url=http://sora.unm.edu/sites/default/files/journals/condor/v082n04/p0469-p0471.pdf |doi=10.2307/1367580 |jstor=1367580 |access-date=2017-01-20 |archive-date=2017-08-12 |archive-url=https://web.archive.org/web/20170812220525/https://sora.unm.edu/sites/default/files/journals/condor/v082n04/p0469-p0471.pdf |url-status=live }} They may serve a similar purpose to eyelashes and vibrissae in mammals. Although there is as yet no clear evidence, it has been suggested that rictal bristles have sensory functions and may help insectivorous birds to capture prey.{{cite magazine |url=http://sora.unm.edu/sites/default/files/journals/wilson/v084n02/p0193-p0197.pdf |title=The role of avian rictal bristles |last=Lederer |first=Roger J. |year=1972 |magazine=The Wilson Bulletin |volume=84 |pages=193–97 |access-date=2017-01-20 |archive-date=2014-02-04 |archive-url=https://web.archive.org/web/20140204025111/http://sora.unm.edu/sites/default/files/journals/wilson/v084n02/p0193-p0197.pdf |url-status=live }} There is some experimental evidence to suggest that bristles may prevent particles from striking the eyes if, for example, a prey item is missed or breaks apart upon contact.}}

{{Term|rosette|content=rosette {{anchor|gape rosette|rosettes|gape rosettes}} }}

{{defn|Also, gape rosette. A fleshy rosette found at the corners of the beaks of some birds, such as the puffin.{{cite magazine|url=http://www.seabirdgroup.org.uk/journals/seabird_27/seabird-27-21.pdf|title=Aging Atlantic Puffins Fratercula arctica in summer and winter|archive-url=https://web.archive.org/web/20160611084736/http://www.seabirdgroup.org.uk/journals/seabird_27/seabird-27-21.pdf|archive-date=June 11, 2016|url-status=dead|last1=Harris|first1=Mike P.|year=2014|magazine=Seabird|volume=27|pages= 22–40}} In the puffin, this is grown as part of its display plumage.{{cite web|url=http://www.welshwildlife.org/wp-content/uploads/2011/05/Puffin.pdf|title=Skomer Island Puffin Factsheet|date=May 2011|publisher=Wildlife Trust of South & West Wales|website=welshwildlife.org|access-date=2017-01-20|archive-date=2020-10-19|archive-url=https://web.archive.org/web/20201019210122/http://www.welshwildlife.org/wp-content/uploads/2011/05/Puffin.pdf|url-status=dead}}}}

{{Term|rhamphotheca}}

{{defn|The outer surface of the beak consisting of a thin horny sheath of keratin, which can be subdivided into the {{gli|rhinotheca}} of the {{gli|upper mandible}} and the {{gli|gnathotheca}} of the {{gli|lower mandible}}. This covering arises from the Malpighian layer of the bird's epidermis, growing from plates at the base of each mandible.{{cite book |title=Veterinary Nursing of Exotic Pets |first=Simon |last=Girling |year=2003 |publisher=Blackwell Publishing |location=Oxford, UK |isbn=978-1-4051-0747-1|page=4}} There is a vascular layer between the rhamphotheca and the deeper layers of the dermis, which is attached directly to the periosteum of the bones of the beak.{{cite book |title=Avian Medicine |editor-first=Jaime |editor-last=Samour |year=2000 |publisher=Mosby |location=London, UK |isbn=978-0-7234-2960-9|page=296}} The rhamphotheca grows continuously in most birds, and in some species, the colour varies seasonally.{{cite magazine| title=Indentation hardness of the bill keratin of the European Starling| last1=Bonse| first1=R.H.| last2=Witter| first2=Mark S.| magazine=The Condor| volume=95| issue=3| pages=736–738| year=1993| url=http://sora.unm.edu/sites/default/files/journals/condor/v095n03/p0736-p0738.pdf| doi=10.2307/1369622| jstor=1369622| access-date=2017-01-19| archive-date=2016-03-04| archive-url=https://web.archive.org/web/20160304210607/http://sora.unm.edu/sites/default/files/journals/condor/v095n03/p0736-p0738.pdf| url-status=live}}}}

{{Term|rhinotheca}}

{{defn|The {{gli|rhamphotheca}} (thin horny sheath of keratin) covering the {{gli|upper mandible}}.}}

{{Term|rump|content=rump {{anchor|rumps|uropygium|parson's nose|pope's nose|sultan's nose|lower back|uropygial region}} }}

{{defn|Also, uropygium; uropygial region; parson's nose, pope's nose; sultan's nose. {{gli|topography|Topographically}}, the region of a bird's {{gli|upperparts}} between the end of the back and the base of the tail. Anatomically, the fleshy protuberance visible at the posterior end of a bird. Its swollen appearance results from it housing the {{gli|uropygial gland}}.{{cite book|last=Damerow|first=Gail|title=The Chicken Encyclopedia: An Illustrated Reference|url=https://books.google.com/books?id=YTkBu_R6jiYC&pg=PA278|year=2012|publisher=Storey Publishing, LLC|isbn=978-1-60342-561-2|page=278}} See related: {{gli|pygostyle}}.}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

File:Riesenseeadler Fang.JPG (Haliaeetus pelagicus)]]

{{Term|scales|content=scales {{anchor|scale|cancella|cancellas|cancellae|scutella|scutellae|cutellas|scute|scutes|acrometatarsium|acrotarsium|Reticulae}} }}

{{defn|Specialized types: cancella; scutella; scutes. Also defined: reticulae; acrometatarsium / acrotarsium. The scales of birds are composed of keratin like their beaks and claws, and are found mainly on the toes and metatarsus, though they may appear further up on the ankle. They do not overlap significantly, except in the cases of kingfishers and woodpeckers. The scales and scutes of birds were originally thought to be homologous to those of reptiles and mammals;{{cite book |last=Lucas |first=Alfred M. |year=1972 |title=Avian Anatomy – integument |location=East Lansing, Michigan |publisher=USDA Avian Anatomy Project, Michigan State University |pages=67, 344, 394–601}} later research, however, suggests that scales in birds re-evolved after the evolution of feathers.Sawyer, R.H., Knapp, L.W. 2003. Avian Skin Development and the Evolutionary Origin of Feathers. J.Exp.Zool. (Mol.Dev.Evol) 298B:57–72.{{cite magazine|magazine=Journal of Anatomy|last=Dhouailly|first=D.|date=April 2009|title=A New Scenario for the Evolutionary Origin of Hair, Feather, and Avian Scales|volume=214|issue= 4|pages=587–606|doi=10.1111/j.1469-7580.2008.01041.x|pmid=19422430|pmc=2736124}} Bird embryos begin development with smooth skin. On the feet, the corneum, or outermost layer of this skin may keratinize, thicken and form scales. Bird scales can be organized into:
i) cancella—minute scales which are really just a thickening and hardening of the skin, crisscrossed with shallow grooves;{{cite book|last1= Lucas|first1=Alfred Martin|last2=Stettenheim|first2=Peter Rich|title=Avian Anatomy Integument|url=https://books.google.com/books?id=GoIWAAAAYAAJ|year=1972|publisher=U.S. Government Printing Office|page=597}}
ii) scutella—scales that are not quite as large as scutes, such as those found on the caudal, or hind part, of the chicken metatarsus; and
iii) scutes—the largest scales, usually on the anterior surface of the metatarsus and dorsal surface of the toes. The rows of scutes on the anterior of the metatarsus is sometimes termed an "acrometatarsium" or "acrotarsium".
Reticulae, by contrast, are small, keeled scale-like structures covering the bottoms of bird feet, but are not true scales. Evolutionary developmental studies on reticulae found that they are composed entirely of alpha-keratin (whereas, true epidermal scales are composed of a mix of alpha and beta keratin). This, along with their unique structure, has led to the suggestion that reticulae are actually feather buds that were arrested early in development.{{cite magazine|last1=Zheng|first1 =X.|last2=Zhou|first2=Z.|last3=Wang|first3=X.|last4=Zhang|first4= F.|last5=Zhang|first5=X.|last6=Wang|first6=Y.|last7=Xu|first7=X.|year=2013|title=Hind wings in basal birds and the evolution of leg feathers|magazine=Science|volume=339|issue= 6125|pages=1309–1312|doi=10.1126/science.1228753|pmid=23493711|bibcode =2013Sci...339.1309Z|citeseerx =10.1.1.1031.5732|s2cid =206544531}} See also: {{gli|podotheca}}.}}

{{Term|scapulars|content=scapulars {{anchor|scapular|scapula|humeral region}} }}

{{defn|Also, humeral region. Feathers covering a bird's scapula "at the base of the dorsal wing".{{Harvnb|Campbell|Lack|1985|p=52}}}}

{{Term|secondaries|content=secondaries {{anchor|secondary feather|secondary feathers|secondary remiges|secondary remex|quill knobs}} }}

{{Main|Flight feather#Secondaries}}

{{defn|Also, secondary feathers; secondary remiges. A type of {{gli|remex}} flight feather, they are connected to the ulna. In some but not all bird species, the ligaments that bind secondaries to the bone connect to small, rounded projections that are called quill knobs. Secondary feathers remain close together in flight (they cannot be individually separated like the primaries can) and help to provide lift by creating the airfoil shape of the bird's wing. Secondaries tend to be shorter and broader than primaries, with blunter ends. They vary in number from six in hummingbirds, to as many as 40 in some species of albatross. In general, larger and longer-winged species have a larger number of secondaries. Birds in more than 40 non-{{gli|passerine}} families are missing the fifth secondary feather on each wing; a state known as {{gli|diastataxis}}.}}

{{Term|semiplume|content=semiplume {{anchor|semiplumes|semi-plume|semi-plumes|semi plume|semi plumes|semiplume feather|semiplume feathers|semi-plume feather|semi-plume feathers|semi plume feather|semi plume feathers}} }}

{{defn|Also, semiplume feather. A type of feather that has features straddling the differences between true {{gli|down}} and {{gli|contour}} feathers, such as by lacking cross-attachment between their {{gli|barbs}} (i.e., without a {{gli|flange}}–{{gli|hooklet}} anchoring system), but having a central, full-length shaft as in contour feathers. They are usually found on the margins of the pennaceous {{gli|pterylae|feather tracts}} and, like down, provide insulative qualities and help fill out the plumage. {{gli|Crest feathers}} are a type of semiplume.{{cite book|last1=Scott|first1=S. David|last2=McFarland|first2=Casey|title=Bird Feathers: A Guide to North American Species|url=https://books.google.com/books?id=LhdExsnFNKIC&pg=PA15|year=2010|publisher=Stackpole Books|isbn=978-0-8117-4217-7|page=15}}{{Harvnb|Pettingill|1985|p=39}}}}

File:Male and female pheasant.jpg, illustrating the dramatic difference in both colour and size between the species' sexes]]

{{Term|sexual dimorphism|content=sexual dimorphism {{anchor|sexually dimorphic|dimorphism|dimorphic}} }}

{{Main|Sexual dimorphism#Birds}}

{{defn|The common phenomenon amongst birds in which males and females of the same species exhibit different characteristics beyond the differences in their sexual organs. It can manifest in size or plumage differences. Sexual size dimorphism varies among taxa with males typically being larger, though this is not always the case, i.e., in birds of prey, hummingbirds and some species of flightless birds.{{cite book|last=Andersson|first=Malte B.|title=Sexual Selection|publisher=Princeton University Press|year=1994|url=https://books.google.com/books?id=lNnHdvzBlTYC|isbn=978-0-691-00057-2|page=269|access-date=2017-03-15|archive-date=2023-01-19|archive-url=https://web.archive.org/web/20230119114446/https://books.google.com/books?id=lNnHdvzBlTYC|url-status=live}}{{cite magazine|title=Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds|magazine=Evolutionary Biology|date=November 11, 2012|issn= 0071-3260|pages= 246–260|volume=40|issue= 2|doi=10.1007/s11692-012-9206-3|first1= Chelsea M.|last1= Berns|first2=Dean C.|last2 =Adams}} Plumage dimorphism, in the form of ornamentation or colouration, also varies, though males are typically the more ornamented or brightly coloured sex.{{cite magazine |last1=McGraw|first1=K. J.|last2=Hill|first2=G. E.|last3=Stradi|first3=R.|last4=Parker|first4=R. S.|year=2002|title=The effect of dietary carotenoid access on sexual dichromatism and plumage pigment composition in the American goldfinch |url=http://www.aces.edu/dept/hilllab/81.pdf|archive-url=https://web.archive.org/web/20050828183926/http://www.aces.edu/dept/hilllab/81.pdf|archive-date=August 28, 2005|magazine=Comparative Biochemistry and Physiology Part B-Biochemistry and Molecular Biology|volume=131|issue= 2|pages=261–269 |doi=10.1016/S1096-4959(01)00500-0|pmid=11818247}} Such differences have been attributed to the unequal reproductive contributions of the sexes.{{cite magazine|last1=Owens|first1=I. P. F.|last2=Hartley|first2=I. R.|year=1998|title=Sexual dimorphism in birds: why are there so many different forms of dimorphism? |magazine=Proceedings of the Royal Society B|volume=265|issue= 1394|pages=397–407|pmc=1688905|jstor=50849|doi=10.1098/rspb.1998.0308}}}}

{{Term|shaft}}

{{defn|See entry for {{gli|rachis}}.}}

{{Term|sides}}

{{defn|The {{gli|topography|topographical}} area between the {{gli|breast}} and the {{gli|back}}, stretching from the {{gli|axilla}} (underarm) to the Iliac crest.{{cite book|last1=Frederick II|first1=(Holy Roman Emperor)|editor-last1=Wood|editor-first1=Casey Albert|editor-last2=Fyfe|editor-first2=Florence Marjorie|title=De Arte Venardi Cum Avibus: Being the De Arte Venandi Cum Avibus of Frederick II of Hohenstaufen|url= https://books.google.com/books?id=TccPuWKAxBkC&pg=PA70|year=1943|publisher=Stanford University Press|isbn=978-0-8047-0374-1|page=72|trans-title=The Art of Falconry}}}}

{{Birdsong|url=http://www.xeno-canto.org/explore?query=Dacelo|species=the Kookaburra|song1=Cucaburra.ogg|caption song1=The extraordinary {{gli|song}} of the Kookaburra}}

{{Term|song|content=song {{anchor|songs}} }}

{{Main|Bird vocalization}}

{{defn|A type of bird vocalization associated with courtship and mating, tending to be longer and more complex than a bird's {{gli|call}}, which serve such functions as giving alarm or keeping members of a flock in contact.}}

File:Mallard speculum.jpg. Note the white-edged, blue and black {{gli|speculum}} seen on the wing.]]

{{Term|speculum|content=speculum {{anchor|speculum feather|speculum feathers|mirror}} }}

{{defn|Also, speculum feathers; mirror. A patch of usually brightly coloured feathers, often iridescent, on the inner {{gli|secondaries|secondary remiges}} in a number of duck species,{{cite book|last=Cooper|first=J.G. |editor-last1=Baird|editor-first1=S.F.|title=Ornithology|url=https://books.google.com/books?id=bfURAwAAQBAJ&pg=PA570|year=1870|publisher=Geological Survey of California, J.D. Whitney, State Geologist|isbn=978-5-87984-211-1|page=570}} though other birds may have them, such as the bright red or orange wing speculum of several parrots from the genus Amazona.{{cite book|last1=Ridgely|first1=Robert S.|last2=Gwynne|first2=John A. Jr. |year=1989|title=Birds of Panama with Costa Rica, Nicaragua, and Honduras|isbn=978-0-691-08529-6|publisher=Princeton University Press}}}}

{{Term|spur|content=spur {{anchor|spurs}} }}

{{defn|Outgrowths of bone covered in a sheath of horn which are found on some birds. Spurs are most commonly found on the feet or legs, though some birds possess spurs on the leading edge of the wings.{{cite magazine|last=Rand|first=A.L.|title=On the spurs on birds' wings|magazine=The Wilson Bulletin|volume=66|issue=2|pages=127–134|url=http://sora.unm.edu/sites/default/files/journals/wilson/v066n02/p0127-p0134.pdf|date=June 1954|access-date=2017-04-24|archive-date=2016-03-03|archive-url=https://web.archive.org/web/20160303165850/http://sora.unm.edu/sites/default/files/journals/wilson/v066n02/p0127-p0134.pdf|url-status=live}}}}

{{Term|sternum|content=sternum {{anchor|sternum|sterna|breastbones|breastbones|breast bone|breast bones|carinate sternum|carinate sterna|ratite sternum|ratite sterna}} }}

{{defn|Plural: sterna. The breastbone of a bird. There are two types: i) carinate sterna—appearing in flighted birds, in which the ventral surface is keel-shaped, which provides ample surface area for attachment of wing muscles used for flight; and ii) ratite sterna—appearing in flightless birds, such as rhea, in which the ventral surface is flattened.{{Harvnb|Pettingill|1985|p=56}}}}

{{Term|submoustachial stripe|content=submoustachial stripe {{anchor|submoustachial stripes|submoustachial-stripe|submoustachial-stripes}} }}

{{defn| A usually light stripe of colour between the {{gli|moustachial stripe}} above, and the {{gli|lateral throat-stripe}} below.}}

{{Term|supercilium|content=supercilium {{anchor|supercilia|superciliary line|superciliary lines|eyebrow|eye brow|eyebrows|eye brows}} }}

{{defn|Plural: supercilia. Also, superciliary line; eyebrow / eye brow. A pale line appearing above the eye of a bird. Compare {{gli|eye stripe}}.}}

{{Term|superior umbilicus|content=superior umbilicus {{anchor|superior umbilicae|distal umbilicus|distal umbilicae}} }}

{{defn|Also, distal umbilicus. A very small opening on the ventral side (facing toward the bird's skin) of a feather's shaft, marking the distal end of the {{gli|calamus}} and the start of the {{gli|rachis}}. It is a remnant of the epithelial tube used by a bird's body to construct the feather. Compare: {{gli|inferior umbilicus}}.}}

{{Term|supraloral|content=supraloral {{anchor|supralorals|supraloral stripe|supraloral stripes|supraloral-stripe|supraloral-stripes}} }}

{{defn|Where a stripe is present only above the {{gli|lores}}, and does not continue behind the eye, it is called a supraloral stripe or simply supraloral, rather than the {{gli|supercilium}}.{{cite book|title=Field Guide to the Birds of North America|editor1-first=Jon L.|editor1-last=Dunn |editor2-first=Jonathan |editor2-last=Alderfer|year=2006|publisher=National Geographic Society |location=Washington, D.C. |isbn=978-0-7922-5314-3|page=10}}}}

{{Term|syrinx}}

{{defn|From the Greek word for pan pipes, σύριγξ, it is the vocal organ of birds. Located at the base of a bird's trachea, it produces sounds without the vocal folds of mammals.{{harvnb|Terres|1980|p=995}} As air flows through the syrinx, sound is produced by the vibration of some or all of the membrana tympaniformis (the walls of the syrinx) and a bar of cartilage connecting the dorsal and ventral extremities, known as the pessulus. This sets up a self-oscillating system that regulates the airflow used to create vocalizations. Sound modulation is achieved by varying the tension of muscles connected to the membranes and bronchial openings involved.{{cite magazine|url=http://jeb.biologists.org/cgi/content/full/205/1/25|title=Direct observation of syringeal muscle function in songbirds and a parrot|last1=Larsen|first1=O. N.|last2=Goller|first2=Franz|magazine=The Journal of Experimental Biology|volume=205|issue=Pt 1|pages=25–35|year=2002|pmid=11818409|access-date=2017-01-22|archive-date=2015-12-22|archive-url=https://web.archive.org/web/20151222080812/http://jeb.biologists.org/content/205/1/25.full|url-status=live}} The syrinx enables some species of birds (such as parrots, crows and mynas) to mimic human speech. Unlike the mammalian larynx, the syrinx is located where the trachea forks into the lungs. Thus, lateralization of bird song is possible, and some songbirds can produce more than one sound at a time.{{cite magazine |last=Suthers |first=R.A. |title=Contributions to birdsong from the left and right sides of the intact syrinx |magazine=Nature |date=October 1990 |volume=347 |issue= 6292 |pages=473–477 |doi=10.1038/347473a0 |bibcode=1990Natur.347..473S}}}}

{{Glossary end}}

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{Glossary}}

{{Term|tail|content=tail {{anchor|tails}} }}

{{defn|While the underlying structure of the tail is made up of bone (the pygostyle{{cite book|last=Cade|first=Thomas Joseph|title=The falcons of the world|url=https://books.google.com/books?id=55fwAAAAMAAJ|year=1982|publisher=Comstock/Cornell University Press|location=Ithaca, N.Y.|isbn=978-0-8014-1454-1|page=13}}) and flesh, the term "tail" is most commonly used to refer to the feathers growing from the region and the shape they form—that is, {{gli|undertail coverts|undertail}} and {{gli|uppertail coverts|uppertail}} coverts and {{gli|rectrices}}, commonly radiating in a fan configuration.}}

{{Term|tail coverts}}

{{defn|See: {{gli|undertail coverts}}, {{gli|uppertail coverts}} and {{gli|crissum}}.}}

File:Eesti rahvuslind.jpg

{{Term|tail streamers|content=tail streamers {{anchor|tail streamer|tail-streamer|tail-streamers}} }}

{{defn|The elongated, narrow tips of the {{gli|tail}} seen in some birds.{{cite magazine|last1=Mo̸ller|first1=A. P.|last2=Barbosa|first2=A.|last3=Cuervo|first3=J. J.|last4=Lope|first4=F. d.|last5=Merino|first5=S.|last6=Saino|first6=N.|title=Sexual selection and tail streamers in the barn swallow|magazine=Proceedings of the Royal Society B: Biological Sciences|volume=265|issue= 1394|year=1998|pages=409–414|issn=0962-8452|doi=10.1098/rspb.1998.0309|pmc=1688894}} They generally function as a sexual ornament.{{cite magazine|last1=Matyjasiak|first1=Piotr|last2=JabŁoński|first2=Piotr G.|title=Hypothetical mechanisms of the initial evolution of sexually dimorphic tail streamers in Hirundinidae|magazine=Evolution|volume=55|issue= 2|year=2001|pages=446|issn=0014-3820|doi=10.1554/0014-3820(2001)055[0446:HMOTIE]2.0.CO;2|pmid=11308101}} In the barn swallow, this has resulted in tail streamers about {{convert|12|mm|in|abbr=on}} longer than is aerodynamically optimal.{{cite magazine|last1=Buchanan|first1=K. L.|title=The effect of tail streamer length on aerodynamic performance in the barn swallow|magazine=Behavioral Ecology|volume=11|issue= 2|year=2000|pages=228–238|issn=1465-7279|doi=10.1093/beheco/11.2.228|doi-access=free}}}}

{{Term|talon|content=talon {{anchor|talons|claw|claws}} }}

{{defn|The claw of a bird of prey; its primary hunting tool.{{cite magazine|doi=10.1371/journal.pone.0007999|last1= Fowler|first1=D.W.|last2=Freedman|first2=E.A.|last3=Scannella|first3=J.B.|year=2009|title=Predatory Functional Morphology in Raptors: Interdigital Variation in Talon Size Is Related to Prey Restraint and Immobilisation Technique|magazine=PLoS ONE|volume=4|issue= 11|pages=e7999|pmid=19946365|pmc=2776979|editor1-last=Pizzari|editor1-first=Tom|bibcode= 2009PLoSO...4.7999F|doi-access= free}} The talons are very important; without them, most birds of prey would not be able to catch their food. Some birds also use claws for defensive purposes. Cassowaries use claws on their inner toe (digit II) for defence, and have been known to disembowel people. All birds, however, have claws, which are used as general holdfasts and protection for the tip of the digits. The hoatzin and turaco are unique among extant birds in having functional claws on the thumb and index finger (digit I and II) on the forelimbs as chicks, allowing them to climb trees until the adult plumage with flight feathers develop.{{cite magazine|last1=Fain|first1=Matthew G.|last2=Houde|first2=Peter|year=2004|title= Parallel radiations in the primary clades of birds|magazine=Evolution|volume=58|issue= 11|pages= 2558–2573|doi=10.1554/04-235|pmid= 15612298|url=http://biology-web.nmsu.edu/~houde/Parallel_radiations.pdf|archive-url=https://web.archive.org/web/20170709030601/http://biology-web.nmsu.edu/~houde/Parallel_radiations.pdf|archive-date=July 9, 2017|url-status=dead}}{{cite magazine|doi=10.1111/j.1096-3642.1891.tb00045.x|last=Parker|first=W. K.|year=1891|url=https://www.biodiversitylibrary.org/page/31083330|title=On the Morphology of a Reptilian Bird, Opisthocomus hoazin|magazine=Transactions of the Zoological Society of London|volume=13|pages=43–89|issue=2|access-date=2018-02-21|archive-date=2017-07-01|archive-url=https://web.archive.org/web/20170701235816/http://www.biodiversitylibrary.org/page/31083330|url-status=live}} However, several birds have a claw- or nail-like structure hidden under the feathers at the end of the hand digits, notably ostriches, emus, ducks, geese and kiwis.Sir Walter Lawry Buller (1888): A History of the Birds of New Zealand. London [http://www.nzetc.org/tm/scholarly/tei-BulBird-t1-g1-t2-body-d138.html excerpt] {{Webarchive|url=https://web.archive.org/web/20110727144959/http://www.nzetc.org/tm/scholarly/tei-BulBird-t1-g1-t2-body-d138.html |date=2011-07-27 }} from Zealand Electronic Text Centre collection}}

File:Squelette oiseau.svg skeleton. Number 8 indicates both left and right {{gli|tarsometatarsus}}]]

{{Term|tarsus|content=tarsus {{anchor|tarsometatarsus|tarsi}} }}

{{defn|Also defined: tarsometatarsus. The third and most conspicuous portion of the bird's leg, from which the toes spring; the foot.{{Harvnb|Newton, et al.|1899|p=948}} In birds, the true tarsus has disappeared, with the proximal tarsals having fused with the tibia, the centralia having disappeared, and the distal bones having fused with the metatarsals to form a single tarsometatarsus bone, effectively giving the leg a third segment.{{cite book|last1=Romer|first1=Alfred Sherwood|last2=Parsons|first2=Thomas S.|year=1977|title=The Vertebrate Body|publisher=Holt-Saunders|location=Philadelphia, PA|pages=205–208|isbn=978-0-03-910284-5}}}}

{{Term|teleoptiles|content=teleoptiles {{anchor|teleoptile}} }}

{{defn|The collective term for all of the feathers of an adult bird.{{Harvnb|Pettingill|1985|p=33}}}}

{{Term|temporal canthus|content=temporal canthus {{anchor|temporal canthi}} }}

{{defn|The area where the eyelids come together at the posterior corner of the eye (toward the sides of the head), as opposed to the {{gli|nasal canthus}}.}}

{{Term|tertiaries|content=tertiaries {{anchor|tertials|tertiary feather|tertiary|humeral feather|humeral feathers}} }}

{{Main|Flight feather#Tertials}}

{{defn|Also, tertials; tertiary feathers; humeral feathers. A type of feather arising in the brachial region, i.e., "proximal to the innermost secondaries", usually growing in a grouping of three to four feathers.{{Harvnb|Proctor|Lynch|1998|p=54}} They are not considered true {{gli|remiges}} as they are not supported by attachment to the corresponding bone—in this case the humerus. These elongated "true" tertials act as a protective cover for all or part of the folded {{gli|primaries}} and {{gli|secondaries}}, and do not qualify as flight feathers as such.{{Cite book|last1=Ferguson-Lees |first1=James |last2= Christie |first2= David A. |title=Raptors of the World |publisher=Christopher Helm |location=London |year=2001 |isbn=978-0-7136-8026-3|page=27}} However, many authorities use the term tertials to refer to the shorter, more symmetrical innermost secondaries of passerines (arising from the olecranon and performing the same function as true tertials) in an effort to distinguish them from other secondaries. The term humeral is sometimes used for birds such as the albatrosses and pelicans that have a long humerus.{{cite magazine|magazine=Auk|title=The trouble with tertials|last1=Hickman|first1=Scott| volume=125| issue= 2| year=2008|page=493|doi=10.1525/auk.2008.2408 | doi-access=free}}{{cite magazine|magazine=The Wilson Bulletin|year=1954|title=The Pterylosis of the Nestling Coua ruficeps|last1=Berger|first1=A.J.|last2=Lunk|first2=W.A.|pages=119–126|volume=66|issue=2|url=http://sora.unm.edu/sites/default/files/journals/wilson/v066n02/p0119-p0126.pdf|access-date=2017-01-16|archive-date=2022-08-08|archive-url=https://web.archive.org/web/20220808145956/http://sora.unm.edu/sites/default/files/journals/wilson/v066n02/p0119-p0126.pdf|url-status=live}}}}

{{Term|throat}}

{{defn|The triangular area of a bird's external anatomy, typically feathered, located between the {{gli|chin}} and the upper part of the {{gli|breast}}.}}

{{Term|thigh}}

{{defn|The {{gli|topography|topographical}} area between the "knee" and the trunk of the body.{{Harvnb|Carnaby|2008|p=11}}}}

{{Term|tibia|content=tibia {{anchor|tibiae|tibias}} }}

{{defn|The usually feathered part of a bird's leg extending above the foot ({{gli|tarsus}}).{{cite book|last1=Schodde|first1=R|last2=Mason|first2=IJ|title=Directory of Australian Birds: Passerines: Passerines|url=https://books.google.com/books?id=XXbJoaGF36YC&pg=PT1122|year=1999|publisher=Csiro Publishing|isbn=978-0-643-10293-4|page=1122}}}}

File:Mergus merganser -Hogganfield Loch, Glasgow, Scotland -female-8.jpg's {{gli|tomia}} help it to hold tight to its fish prey.]]

{{Term|tomia|content=tomia {{anchor|tomium}} }}

{{Main|Beak#Tomia}}

{{defn|Singular: tomium. The cutting edges of the {{gli|upper mandible|upper}} and {{gli|lower mandible|lower}} mandibles. In most birds, these range from rounded to slightly sharp, but some species have evolved structural modifications that allow them to handle their typical food sources better.{{cite magazine |magazine=Integrative and Comparative Biology |title=The Integumentary Morphology of Modern Birds—An Overview |first=Peter R. |last=Stettenheim |volume=40 |issue= 4 |pages=461–477 |url=http://icb.oxfordjournals.org/content/40/4/461.full.pdf+html |format=PDF |doi=10.1093/icb/40.4.461 |url-status=dead |archive-url=https://web.archive.org/web/20120420052438/http://icb.oxfordjournals.org/content/40/4/461.full.pdf+html |archive-date=April 20, 2012 |year=2000 |doi-access=free }} Granivorous (seed-eating) birds, for example, have ridges in their tomia, which help the bird to slice through a seed's outer hull.{{cite magazine |doi=10.1016/S1055-937X(99)80036-X |title=Avian gastrointestinal anatomy and physiology |year=1999 |last1=Klasing |first1=Kirk C. |magazine=Seminars in Avian and Exotic Pet Medicine |volume=8 |issue= 2 |pages=42–50}} Birds in roughly 30 families have tomia lined with tight bunches of very short bristles along their entire length. Most of these species are either {{gli|insectivores}} (preferring hard-shelled prey) or snail eaters, and the brush-like projections may help to increase the coefficient of friction between the mandibles, thereby improving the bird's ability to hold hard prey items.{{cite magazine |magazine=The Wilson Bulletin |volume=105 |issue=2 |date=June 1993 |pages=316–324 |title=Scopate Tomia: An Adaptation for Handling Hard-shelled Prey? |first=Kenneth L. |last=Gosner |url=http://sora.unm.edu/sites/default/files/journals/wilson/v105n02/p0316-p0324.pdf |access-date=2017-01-17 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304081831/http://sora.unm.edu/sites/default/files/journals/wilson/v105n02/p0316-p0324.pdf |url-status=live }} Serrations on hummingbird bills, found in 23% of all hummingbird genera, may perform a similar function, allowing the birds to effectively hold insect prey. They may also allow shorter-billed hummingbirds to function as nectar thieves, as they can more effectively hold and cut through long or waxy flower corollas.{{cite magazine |magazine=The Auk |volume=111 |issue=3 |pages=703–710 |title=Serrate Tomia: An Adaptation for Nectar Robbing in Hummingbirds? |first=Juan Francisco |last=Ornelas |url=http://sora.unm.edu/sites/default/files/journals/auk/v111n03/p0703-p0710.pdf |access-date=2017-01-17 |archive-date=2016-03-05 |archive-url=https://web.archive.org/web/20160305195625/http://sora.unm.edu/sites/default/files/journals/auk/v111n03/p0703-p0710.pdf |url-status=live }} In some cases, the colour of a bird's tomia can help to distinguish between similar species. The snow goose, for example, has a reddish-pink bill with black tomia, while the whole beak of the similar Ross's goose is pinkish-red, without darker tomia.{{cite book |title=Wildfowl |publisher=Christopher Helm |location=London |year=1988 |pages=143–144 |first1=Steve |last1=Madge |first2=Hilary |last2=Burn |isbn=978-0-7470-2201-5}}}}

{{Term|topography|content=topography}}

{{defn|The mapping of external features of bird anatomy.{{Harvnb|Pettingill|1985|page=8}}}}

{{Term|torpor|content=torpor {{anchor|torpors|hypometabolism}} }}

{{defn|Also, hypometabolism. An energy-conserving strategy used by some small birds [under {{convert|100|g|oz|abbr=on}}] in which they become inactive and unreactive to external stimuli, and reduce their metabolism below their normal respiration and heart rate, causing decreases in body temperature by an average of {{convert|4|-|35|C|F}}. Two types of torpor are recognized. In one type, such as in hummingbirds, torpor may be entered on a daily basis and last only a few hours; other behaviours, such as foraging, continue during non-torpor periods. For other species, torpor may only be entered during cold conditions or when food becomes limited, but may persist for weeks or even months. The extent of unresponsiveness during torpor can be pronounced. A hummingbird in deep torpor, for example, with a body temperature of {{convert|18|C|F}}, will not respond to a variety of external stimuli, such as attempts to push it from a perch; only the locking reflex of the feet stops the bird from falling. Torpor has been reported in eight orders of birds.{{cite magazine|last=Schleucher|first=Elke|title=Torpor in birds: taxonomy, energetics, and ecology|magazine=Physiological and Biochemical Zoology|volume=77|issue= 6|year=2004|pages=942–949|doi=10.1086/423744|pmid=15674768}}{{cite magazine|last=Brigham|first=R. Mark|title=Daily torpor in a free-ranging goatsucker, the common poorwill (Phalaenoptilus nuttallii)|magazine=Physiological Zoology|volume=65|issue= 2|year=1992|pages=457–472|jstor=30158263|doi=10.1086/physzool.65.2.30158263}}}}

{{Glossary end}}

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{{Glossary}}

{{Term|undertail coverts|content=undertail coverts {{anchor|undertail covert|undertail-coverts|undertail-covert|under tail covert|under-tail covert|under-tail-covert|under tail-covert|under tail coverts|under-tail coverts|under-tail-coverts|under tail-coverts}} }}

{{defn|{{gli|Covert feathers}} covering the base of the {{gli|tail}} on its underside. Compare: {{gli|uppertail coverts}}; contrast {{gli|wing coverts}}.}}

File:Underwing.svg

{{Term|underwing|content=underwing {{anchor|underwings|under-wing|under-wings|under wing|under wings}} }}

{{defn|The bottom side of a bird's wing; the hidden surface of the wing when it is folded.{{Cite OED|Underwing}} Compare: {{gli|upperwing}}.}}

{{Term|upper mandible|content=upper mandible {{anchor|maxilla|upper mandibles|upper maxilla}} }}

{{Main|Beak#Mandibles}}

{{defn|Also, maxilla. The upper part of a bird's {{gli|bill}} or beak, roughly corresponding to the upper jaw of mammals, it is supported by a three-pronged bone called the intermaxillary. The upper prong of this bone is embedded into the forehead, while the two lower prongs attach to the sides of the skull. At the base of the upper mandible a thin sheet of nasal bones is attached to the skull at the nasofrontal hinge, which gives mobility to the upper mandible, allowing it to move upwards and downwards. The outer surface is covered in a thin, horny sheath of keratin called {{gli|rhamphotheca}} specially called {{gli|rhinotheca}} in the upper mandible. Compare: {{gli|lower mandible}}.}}

{{Term|upper parts|content=upper parts {{anchor|upper-parts|upperparts}} }}

{{defn|Also, upper-parts and upperparts. The {{gli|topography|topographical}} areas above the eyes of a bird (generally not including the {{gli|eyestripe}}, if any) and through all of a bird's upper surface, including the "{{gli|crown}}, {{gli|mantle}}, {{gli|back}}, {{gli|tertials}} and {{gli|inner wing-coverts}}",{{cite magazine|magazine=RAOU Newsletter|volume=21|issue= 4|title=Wing Span| year=2011| page=17 |oclc=23961486}} although the term is sometimes used more inclusively, for all features from the bill to the tail.{{cite book|title=Birds of California: An Introduction to More than 300 Common Birds of the State and Adjacent Islands| location=Chicago|last=Wheelock|first=Irene Grosvenor|page=15|publisher=A.C. McClurg|date=1904|url=https://books.google.com/books?id=RZoaAAAAYAAJ&pg=PR15|oclc=2064174}} Compare: {{gli|under parts}}.}}

{{Term|under parts|content=under parts {{anchor|under-parts|underparts|lower parts|lower-parts|lowerparts}} }}

{{defn|Also, under-parts; underparts; lower parts; lower-parts; lowerparts. All {{gli|topography|topographical}} areas on the underside or "under surface" of a bird, i.e., from the {{gli|chin}} to the underside end of the tail (on the trunk and thus not including the legs). Compare {{gli|upper parts}}.}}

{{Term|uppertail coverts|content=uppertail coverts {{anchor|uppertail covert|uppertail-coverts|uppertail-covert|upper tail covert|upper-tail covert|upper-tail-covert|upper tail-covert|upper tail coverts|upper-tail coverts|upper-tail-coverts|upper tail-coverts}} }}

{{defn|{{gli|Covert feathers}} covering the base of the {{gli|tail}} on its upperside. Sometimes these coverts are more specialized. The "tail" of a peacock is actually very elongated uppertail coverts. Compare {{gli|undertail coverts}}; contrast {{gli|wing coverts}}.}}

{{Term|upperwing|content=upperwing {{anchor|upperwings|upper-wing|upper-wings|upper wing|upper wings}} }}

{{defn| The top, or upper, side of a bird's wing.{{cite web|title=Glossary of Bird Terms|url=http://www.nebraskabirdlibrary.org/resources/glossary-of-bird-terms/|website=www.nebraskabirdlibrary.org|access-date=March 26, 2017|archive-date=March 27, 2017|archive-url=https://web.archive.org/web/20170327081244/http://www.nebraskabirdlibrary.org/resources/glossary-of-bird-terms/|url-status=usurped}} Compare: {{gli|underwing}}.}}

{{Term|uropygial gland|content=uropygial gland {{anchor|uropygial glands|uropygial|preen gland|preen glands|oil gland|oil glands}} }}

{{defn|Also, preen gland; oil gland. A gland found at the {{gli|rump}}, at the base of the {{gli|tail}} that produces a waxy secretion made up of oils, fatty acids, fats and water that the majority of birds use in daily {{gli|preening}} of their feathers. Though feathers {{gli|moult}} periodically, they are inert structures without a nourishment system and would deteriorate rapidly without such application during preening. The applied waxy secretion aids in waterproofing, helps maintain feather moistness to keep them from becoming brittle and maintain flexibility, and is thought to promote the growth of nonpathogenic fungi, to deter feather lice and some forms of keratin-eating fungi and bacteria. The gland, a bilobed structure, is usually surrounded by a tuft of downy feathers that can act like a wick for the secreted oils.{{Harvnb|Gill|1995|p=102}}}}

{{Term|uropygium}}

{{defn|See {{gli|rump}}.}}

{{Glossary end}}

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{{Glossary}}

{{term|vagrant}}

{{defn|Descriptive of a bird found outside its species' or subspecies' normal migration range or distribution area.{{Cite OED|vagrant}}}}

{{Term|vane|content=vane {{anchor|vanes|vexillum|vaxillum|vexilla|outer vane|outer vanes|outer-vane|outer-vanes|inner vane|inner vanes|inner-vane|inner-vanes}} }}

{{defn|Also, vexillum – plural: vexilla. The weblike expanse of flexible barbs, more or less interconnected by the {{gli|hooklets}} of the {{gli|barbules}}, extending from each side of the distal part of the feather's shaft known as the {{gli|rachis}}. One side of the vane, called the outer vane, overlaps the inner vane side of the feather next to it.}}

{{Term|vanule}}

{{defn|The collective term for all of the {{gli|barbules}} branching from the {{gli|ramus}} of a feather's {{gli|barb}}.}}

{{Term|vaned feather|content=vaned feather {{anchor|vaned feathers}} }}

{{defn|A classification term for pennaceous feathers (aka contour feathers) that clothe the outside of a bird's body.{{cite book|last=Alderfer|first=Jonathan K.|title=Bird-watcher's Bible: A Complete Treasury: Science, Know-how, Beauty, Lore|url=https://books.google.com/books?id=FkT761I4150C&pg=PT33|year=2012|publisher=National Geographic|isbn=978-1-4262-0964-2|page=32}} It refers to the {{gli|vane|vaned}} property of such feathers, i.e., having a flattened weblike expanse of flexible {{gli|barbs}}, more or less interconnected by the {{gli|hooklets}} of the {{gli|barbules}}, extending from each side of the distal part of the feather's shaft known as the {{gli|rachis}}. They make up one of three broad classes of feathers, the others being {{gli|down feathers}} (which lie underneath vaned feathers, if present), and the hairlike {{gli|filoplumes}}.}}

{{Term|vent|content=vent {{anchor|vents}} }}

{{defn|The external opening of the {{gli|cloaca}}.{{cite book|last=Kahn|first=Cynthia M.|title=The Merck/Merial Manual For Pet Health: The complete health resource for your dog, cat, horse or other pets – in everyday language|url=https://books.google.com/books?id=eE2IvM10IX4C&pg=PA849|year=2007|publisher=Simon and Schuster|isbn=978-0-911910-99-5|page=849}}}}

{{Term|vent pecking}}

{{main|Vent pecking}}

{{defn|An abnormal behaviour of birds in captivity, performed primarily by commercial egg-laying hens, characterized by pecking damage to the {{gli|cloaca}}, the surrounding skin and underlying tissue.Sherwin, C.M., (2010). The welfare and ethical assessment of housing for egg production. In The Welfare of Domestic Fowl and Other Captive Birds, I.J.H. Duncan and P. Hawkins (eds), Springer, pp. 237–258 Vent pecking frequently occurs immediately after an egg has been laid when the cloaca often remains partly everted exposing the mucosa.{{cite magazine|magazine=Applied Animal Behaviour Science|last1=Potzsch|first1=C. J.|last2=Lewis|first2=K.|last3=Nicol|first3=C. J.|last4=Green|first4=L. E.|year=2001|title=A cross-sectional study of the prevalence of vent pecking in laying hens in alternative systems and its associations with feather pecking, management and disease|volume=74|issue= 4|pages=259–272|doi=10.1016/S0168-1591(01)00167-8}}}}

{{Glossary end}}

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{{Glossary}}

File:Flickr - Rainbirder - Bearded Bellbird (Procnias averano) male calling.jpg {{gli|calling}} in the Arima Valley of Trinidad. Note the beard-like {{gli|wattles}} sprouting from its {{gli|chin}} and {{gli|throat}} area, for which the bird is named.]]

{{Term|wattle|content=wattle {{anchor|wattles|dewlap|dewlaps|rictal wattle|rictal wattles}} }}

{{defn|Also, dewlap; lappet; palearia. Specialized type: rictal wattle. A type of {{gli|caruncle}}, the wattle is a flap or lobe of flesh, often of a vivid colour, that hangs from the head of some birds, often from the chin or throat.{{Cite OED|Wattle}}{{cite book|last1=Cruickshank|first1=Allan D. |last2=Cruickshank|first2=Helen Gere |title=1001 Questions Answered about Birds|url=https://books.google.com/books?id=96KxUxvA4H4C&pg=PA97|year=1976|publisher=Courier Corporation|isbn=978-0-486-23315-4|page=97}} When found at the corner of the mouth, they may be called rictal wattles, such as in masked lapwings.{{cite book|last=Kochan|first=Jack B. |title=Bills & mouths|url=https://books.google.com/books?id=ybRPAAAAYAAJ|date=September 1995|publisher=Stackpole Books|isbn=978-0-8117-3057-0|page=12}} Birds with wattles include turkeys, guineafowls, northern cassowaries, black-faced ibises, North Island kōkakos, wattled starlings (males, when in {{gli|nuptial plumage}}) and male bearded bellbirds, with the last having startling, beard-like wattles.{{cite book | last1=Stark | first1=Arthur Cowell | title=The Birds of South Africa Vol. 1 | url=https://biodiversitylibrary.org/page/19014806 | year=1900 | volume=1 | place=London | publisher=R. H. Porter | page=23 | access-date=2018-09-27 | archive-date=2018-09-28 | archive-url=https://web.archive.org/web/20180928003631/https://www.biodiversitylibrary.org/page/19014806 | url-status=live }}{{cite book|last=Kricher|first=John |title=A Neotropical Companion: An Introduction to the Animals, Plants, and Ecosystems of the New World Tropics. Illustrated by Andrea S. LeJeune|url=https://books.google.com/books?id=b2sZBgAAQBAJ&pg=PA273|date=February 18, 2015|publisher=Princeton University Press|isbn=978-1-4008-6691-5|page=273}}}}

{{term|whiffling}}

{{defn|A flight behaviour in which a bird rapidly descends with a zig-zagging, side-slipping motion. During whiffling, some birds invert the aerodynamic mechanics of their bodies that normally provide lift—flying by turning their bodies upside down but with their necks twisted 180 degrees to keep their heads in a normal flying position—resulting in a rapid plummet, before a quick arrest of the fall by resumption of a normal flying orientation.{{cite magazine|author-last1=Ogilvie |author-first1=M.A. |author-last2=Wallace|author-first2=D.I.M.|title=Field identification of grey geese|magazine=British Birds|volume=68|year=1975|pages=57–67}}{{cite web|publisher=New Scientist TV|last=Ceurstemont|first=Sandrine|url=https://www.newscientist.com/blogs/nstv/2012/01/first-slow-mo-video-of-goose-flying-upside-down.html|date=January 25, 2012|access-date=April 19, 2017|title=Goose flying upside down captured in slow-mo movie|archive-date=August 17, 2017|archive-url=https://web.archive.org/web/20170817082810/https://www.newscientist.com/blogs/nstv/2012/01/first-slow-mo-video-of-goose-flying-upside-down.html|url-status=live}}{{cite book|last=Attenborough|first=David |title=The life of birds|url=https://books.google.com/books?id=HO0PAQAAMAAJ|date=September 24, 1998|publisher=BBC|isbn=978-0-563-38792-3|page=49}}}}

File:Pine Siskin Female (10743)-Relic38.JPG with white {{gli|wing bars}}.]]

{{Term|wing bar|content=wing bar {{anchor|wing-bar|wing bars|wing-bars|wingbar|wingbars}} }}

{{defn|A stripe found on the {{gli|upperwing}} that is created by the contrast of the tips of the primary and secondary coverts.{{cite book|last1=Dunn|first1=Jon Lloyd |last2=Alderfer|first2=Jonathan K. |title=National Geographic Field Guide to the Birds of North America|url=https://books.google.com/books?id=gA-rfkTZi1YC&pg=PA12|year=2006|publisher=National Geographic Books|location=Washington D.C.|isbn=978-0-7922-5314-3|page=12}} This feature may disappear when a bird {{gli|moults}} and takes on a different seasonal {{gli|plumage}}.{{cite book|last1=Brooks|first1=W.E.|last2=Etáwah|first2=C.E.|editor=The Honorary Secretaries|title=Proceedings of the Asiatic Society of Bengal: 1872 – Brooks on Imperial Eagles of India|url=https://books.google.com/books?id=5s5TAAAAcAAJ&pg=PA65|year=1872|publisher=C.B. Lewis, Baptist Mission Press|location=Calcutta|page=65}} Wing bars often occur in pairs.{{harvnb|Floyd|2008|p=498}} Contrast: {{gli|speculum}}.}}

{{Term|wing clipping|content=wing clipping {{anchor|wing trimming}} }}

{{Main|Wing clipping}}

{{defn|Also, wing trimming. The controversial practice of trimming a bird's {{gli|primaries|primary wing feathers}} or {{gli|remiges}} so that it is not fully flight-capable, until it grows replacement feathers during its next {{gli|moult}}.{{cite web|url=https://theparrotsocietyuk.org/site/index.php/parrot-information/veterinary-advice/wing-clipping/|last=Jones|first=Alan K|title=Wing Clipping in Pet Birds - a study and comparison of techniques|publisher=The Parrot Society UK|access-date=December 21, 2020|archive-date=January 16, 2021|archive-url=https://web.archive.org/web/20210116155210/https://theparrotsocietyuk.org/site/index.php/parrot-information/veterinary-advice/wing-clipping/|url-status=live}} If it is performed correctly, it is a painless procedure.{{cite web |last1=Hess |first1=Laurie, DVM |title=How to Clip a Bird's Wings |url=https://www.petmd.com/bird/grooming/how-clip-birds-wings |website=PetMD |date=February 27, 2017 |access-date=22 December 2020 |archive-date=29 October 2020 |archive-url=https://web.archive.org/web/20201029234730/https://www.petmd.com/bird/grooming/how-clip-birds-wings |url-status=live }} Nevertheless, the practice can cause injury, e.g., hemorrhaging as the result of {{gli|blood feathers}} being accidentally trimmed.{{cite book|last=Speer|first=Brian |title=Current Therapy in Avian Medicine and Surgery|url=https://books.google.com/books?id=tclQCwAAQBAJ|year=2015|publisher=Elsevier Health Sciences|isbn=978-0-323-24367-4|page=700}}}}

File:chicken wing.svg

{{Term|wing coverts|content=wing coverts {{anchor|wing covert|wing-covert|wing-coverts|upperwing coverts|underwing coverts|secondary coverts|primary coverts|greater primary coverts|greater secondary coverts|median primary coverts|median secondary coverts|lesser primary coverts|lesser secondary coverts|lesser underwing coverts|lesser underwing primary coverts|median underwing coverts|greater underwing primary coverts|greater underwing coverts|upperwing covert|underwing covert|secondary covert|primary covert|greater primary covert|greater secondary covert|median primary covert|median secondary covert|lesser primary covert|lesser secondary covert|lesser underwing covert|lesser underwing primary covert|median underwing covert|greater underwing primary covert|greater underwing covert|lesser covert|lesser coverts|greater covert|greater coverts|median|median coverts|median covert}} }}

{{defn|Also defined: upperwing coverts; underwing coverts; secondary coverts; primary coverts; greater (primary-/secondary-) coverts; median (primary-/secondary-) coverts; lesser (primary-/secondary-) coverts (the last being also called bow coverts).
{{gli|Covert feathers}} found on a bird's {{gli|wing}}. There are a number of classes and subclasses. The {{gli|upperwing}} coverts fall into two groups: those on the {{gli|inner wing}}, which overlay the secondary flight feathers, are known as the secondary coverts, and those on the {{gli|outer wing}}, which overlay the primary flight feathers, are known as the primary coverts. Within each group, the feathers form a number of rows. The feathers of the outermost, largest, row are termed greater (primary-/secondary-) coverts; those in the next row are the median (primary-/secondary-) coverts, and any remaining rows are termed lesser (primary-/secondary-) coverts. The {{gli|underwing}} has corresponding sets of coverts (the names upperwing coverts and underwing coverts are used to distinguish the corresponding sets). In addition, the front edge of the wing is covered with a group of feathers called the marginal coverts. Within each group of wing coverts, the rows of feathers overlap each other like roof tiles (the greater coverts are overlain by the median coverts, which in turn are overlain by the outermost row of lesser coverts, and so on).{{Harvnb|Pettingill|1985|pages=16–21}} See also: {{gli|axillaries}}; {{gli|ear coverts}}; {{gli|wing lining}} (marginal coverts).}}

{{Term|wing formula|content=wing formula {{anchor|wing formulae}} }}

{{Main|Flight feather#Wing formula}}

{{defn|A mathematical classification of the shape of the distal end of a bird's wing. It can be used to help distinguish between species with similar {{gli|plumages}}, and thus is particularly useful for those who ring (band) birds. To determine a bird's wing formula, the exposed distance between the tip of the most distal {{gli|primary}}, and the tip of its {{gli|greater covert}} (the longest of the feathers that cover and protect the shaft of that primary), is measured in millimetres. In some cases, this results in a positive number (e.g., the primary extends beyond its greater covert), while in other cases it is a negative number (e.g., the primary is completely covered by the greater covert, as happens in some passerine species). Next, the longest primary feather is identified, and the differences in millimetres is measured between: i) the length of that primary; ii) that of all of the remaining primaries; and iii) of the longest secondary. If any primary shows a notch or {{gli|emargination}}, this is noted, and the distance between the feather's tip and any notch is measured, as is the depth of the notch. All distance measurements are made with the bird's wing closed, so as to maintain the relative positions of the feathers. While there can be considerable variation across members of a species—and while the results are obviously impacted by the effects of {{gli|moult}} and feather regeneration—even very closely related species show clear differences in their wing formulae.}}

{{Term|wing lining|content=wing lining {{anchor|wing linings|winglining|winglinings|wing-lining|wing-linings|marginal coverts|marginal-coverts|marginal-coverts|median primary covert|median secondary covert|median primary coverts|median secondary coverts}} }}

{{defn|Also, marginal coverts. A grouping of very soft {{gli|covert feathers}} lining the anterior edge of the underside of the wing. Though the wing lining is composed of rows of these feathers, they are smooth in appearance such that it is often impossible to see the demarcation of the rows solely by eye.}}

{{Term|wings|content=wings {{anchor|wing|elliptical wing|elliptical wings|high speed wing|high speed wings|high aspect ratio wing|high aspect ratio wings|soaring wing|soaring wings}} }}

{{defn|Wing types defined: elliptical; high speed; high aspect ratio; soaring. The bird's forelimbs that are the key to flight. Each wing has a central axis, composed of three limb bones: the humerus, ulna and radius. The hand, or manus, which ancestrally was composed of five digits, is reduced to three digits (digit II, III and IV or I, II, III depending on the scheme followedBaumel, J.J. (1993) Handbook of Avian Anatomy: Nomina Anatomica Avium. 2nd Ed. Nuttall Ornithological Club. Cambridge, MA), which serves as an anchor for the {{gli|primaries}}, one of two groups of flight feathers responsible for the wing's airfoil shape. The other set of flight feathers, behind the carpal joint on the ulna, are called the {{gli|secondaries}}. The remaining feathers on the wing are known as {{gli|coverts}}, of which there are three sets. The wing sometimes has vestigial claws. In most species these are lost by the time the bird is adult (such as the highly visible ones used for active climbing by hoatzin chicks), but claws are retained into adulthood by the secretarybird, screamers, finfoots, ostriches, several swifts and numerous others, as a local trait, in a few specimens. Bird wings are generally grouped into four types: i) elliptical wings—short, rounded and having a low aspect ratio, they allow for tight maneuvering in confined spaces such as might be found in dense vegetation. They are common in forest raptors, many migratory species of passerines, and in species such as pheasants and partridges that use a rapid take-off to evade predators. ii) High speed wings—short, pointed wings that, when combined with a heavy wing loading and rapid wingbeats, provide an energetically expensive high speed, as used by the bird with the fastest wing speed, the peregrine falcon. Most ducks and auks have this type of wing but use the configuration for a different purpose, to "fly" underwater. iii) High aspect ratio wings—typified by low wing loading and being far longer than they are wide, they are used for slower flight, which may take the form of almost hovering (as used by kestrels, terns and nightjars), or in soaring and gliding flight, particularly the dynamic soaring used by seabirds, which takes advantage of wind speed variation at different altitudes (wind shear) above ocean waves to provide lift. iv) Soaring wings with deep slots—common in larger species of inland birds, such as eagles, vultures, pelicans and storks. The slots at the end of the wings, between the primaries, reduce the induced drag and wingtip vortices, while the shorter size of the wings aids in takeoff (high aspect ratio wings require a long taxi to get airborne).{{Harvnb|Feduccia|1999|pages=16–18}}}}

File:Bee hummingbird (Mellisuga helenae) adult male in flight-cropped.jpg in flight; the bird with the smallest {{gli|wingspan}} at {{convert|6.6|cm|in|abbr=on}}.]]

{{Term|wingspan|content=wingspan {{anchor|wingspans|wing span|wing spans}} }}

{{defn|The distance between each of the tips of the fully extended {{gli|wings}}.{{cite web|title=Bird Academy's A-to-Z Glossary of Bird Terms|url=https://academy.allaboutbirds.org/bird-academys-a-to-z-glossary-of-bird-terms/|access-date=March 19, 2017|date=September 9, 2016|archive-date=March 20, 2017|archive-url=https://web.archive.org/web/20170320144412/https://academy.allaboutbirds.org/bird-academys-a-to-z-glossary-of-bird-terms/|url-status=live}} The living bird species with the largest wingspan is the wandering albatross, typically ranging from {{convert|2.5|to|3.5|m|ftin|abbr=on}}.{{cite book|last=Elphick|first=Jonathan|title=The Atlas of Bird Migration: Tracing the Great Journeys of the World's Birds|url=https://books.google.com/books?id=j91I9I4pq20C&pg=PT159|year=2007|publisher=Struik|isbn=978-1-77007-499-6|pages=154–155}}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }} In contrast, the living bird species with the smallest wingspan is the bee hummingbird (also the smallest bird overall) with a wingspan of just {{convert|6.6|cm|in|abbr=on}}.{{cite book|last=Williams|first=Ernest H. Williams Jr. |title=The Nature Handbook: A Guide to Observing the Great Outdoors|url=https://books.google.com/books?id=VoV7CclhNJcC&pg=PA94|year=2005|publisher=Oxford University Press|isbn=978-0-19-972075-0|page=94}}}}

{{Term|winter plumage}}

{{defn|See {{gli|basic plumage}}.}}

{{Glossary end}}

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{{Glossary}}

{{Term|zygodactylous|content=zygodactylous|zygodactyl|zygodactyl foot|zygodactyl feet|yoke-toed|zygodactylous foot|zygodactylous feet|heterodactylous|heterodactyl|heterodactyl foot|heterodactyl feet|heterodactylous foot|heterodactylous feet}}

{{defn|Also, yoke-toed. Also defined: heterodactylous. Descriptive of tetradactyl (four-toed) birds in which the architecture of the foot consists of two toes projecting forward and two toes projecting backward, such as in parrots, woodpeckers and cuckoos. In most birds with zygodactylous feet, the forward projecting toes are the second and third toes and the backward projecting toes are the fourth toe and {{gli|hallux}}. However, in trogons alone, the third and fourth toes are in front, and the second and hallux are behind. This arrangement is sometimes separately designated, and termed heterodactylous.{{Harvnb|Coues|1890|p=187}}}}

{{Glossary end}}

• Glossary of dinosaur anatomy

{{Compact TOC|side=yes|center=yes|top=yes|nobreak=yes|x=|custom1=Explanatory footnotes|custom2=Citations|custom3=Bibliography}}

{{notelist}}

{{Reflist|30em}}

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{{Birds|state=collapsed}}

Category:Birds

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Bird

Category:Wikipedia glossaries using description lists