Common grackle

The common grackle was first described in 1758 by Carl Linnaeus in the tenth edition of Systema Naturae, as Gracula quiscula. It was assigned to the genus Quiscalus by French ornithologist Louis Pierre Vieillot in his 1816 Dictionnaire d'histoire naturelle.{{cite journal |title=Races of Quiscalus quiscula |author=Oberholser, Harry |author-link=Harry Oberholser |journal=The Auk |volume=36 |issue=4 |date=October 1919 |jstor=4073352 |doi=10.2307/4073352 |pages=549–555|url=https://www.biodiversitylibrary.org/part/85979 |doi-access=free }}

Three subspecies are recognized:{{cite web |title=Quiscalus quiscula |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=179104#null |website=Integrated Taxonomic Information System |access-date=28 May 2017}}{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | year=2017 | title=New World warblers & oropendolas, Bananaquit | work=World Bird List Version 7.2 | url=http://www.worldbirdnames.org/bow/warblers/ | publisher=International Ornithologists' Union | access-date=28 May 2017 }}

• the Florida grackle (Q. q. quiscula) (Linnaeus 1758), the nominate subspecies
• the purple grackle (Q. q. stonei) (Chapman, 1935){{cite journal |title=Further Remarks on the Relationships of the Grackles of the Subgenus Quiscalus |author=Chapman, Frank |author-link=Frank Chapman (ornithologist) |journal=The Auk |volume=52 |issue=1 |date=January 1935 |pages=21–29 |jstor=4077103 |doi=10.2307/4077103 }}
• the bronzed grackle (Q. q. versicolor) (Vieillot, 1816)

Image:Common Grackle male RWD.jpg

Adult common grackles measure from {{convert|28|to|34|cm|in|abbr=on}} in length, span {{convert|36|-|46|cm|in|abbr=on}} across the wings, and weigh {{convert|74|-|142|g|oz|abbr=on}}.{{cite web| title=Common Grackle| publisher=Cornell Lab of Ornithology| url=http://www.allaboutbirds.org/guide/Common_grackle/lifehistory}} Common grackles are less sexually dimorphic than larger grackle species, but the differences between the sexes can still be noticeable. The male, which averages {{convert|122|g|oz|abbr=on}}, is larger than the female, at an average of {{convert|94|g|oz|abbr=on}}.{{cite web| publisher=Animal Diversity Web| title=Quiscalus quiscula, common grackle| url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Quiscalus_quiscula.html}} Adults have a long, dark bill, pale yellowish eyes, and a long tail; their feathers appear black with purple, green, or blue iridescence on the head, and primarily bronze sheen in the body plumage. Adult females, beyond being smaller, are usually less iridescent; their tails in particular are shorter, and unlike the males, do not keel (display a longitudinal ridge) in flight and are brown with no purple or blue gloss. Juveniles are brown with dark brown eyes.

When grackles are in a group, they are referred to as a "plague".{{cite book

| last = Murphy-Hiscock

| first = Arin

| title = Birds - A Spiritual Field Guide: Explore the Symbology and Significance of These Divine Winged Messengers

| publisher = Adams Media

| date = January 2012

| pages = 86

| isbn = 978-1-4405-2688-6}}

File:Common Grackle 5-26-2018.jpg, New York]]

File:Spinus-common-grackle-2015-03-n029780-w.jpg

The breeding habitat is open and semiopen areas across North America east of the Rocky Mountains. The nest is a well-concealed cup in dense trees (particularly pine) or shrubs, usually near water; sometimes, the common grackle nests in cavities or in man-made structures. It often nests in colonies, some being quite large. Bird houses are also a suitable nesting site. Four to seven eggs are in a clutch.

This bird is a permanent resident in much of its range. Northern birds migrate in flocks to the Southeastern United States. The distribution of the common grackle is largely explained by annual mean temperature, and the species has expanded its range by greater than three-fold since the last glacial maximum, approximately 22,000 years ago.{{Cite journal |last1=Capainolo |first1=Peter |last2=Perktaş |first2=Utku |last3=Fellowes |first3=Mark D.E. |date=July 1, 2020 |title=Late Quaternary Range Dynamics in the Common Grackle Quiscalus quiscula|journal=Ardea |volume=108|issue=1|pages=95|doi=10.5253/arde.v108i1.a8|issn=0373-2266|doi-access=free|url=https://centaur.reading.ac.uk/90005/9/arde.v108i1.a8%20%281%29.pdf }}

File:(Grackle close up.) - DPLA - 6344e4b51fa8dcc7120d63d690bb4a5f.jpg

The common grackle forages on the ground, in shallow water, or in shrubs; it may steal food from other birds. It is omnivorous, eating insects, minnows, frogs, eggs, berries, seeds, grain, and even small birds and rodents. Grackles at outdoor eating areas often wait eagerly until someone drops some food. They rush forward and try to grab it, often snatching food out of the beak of another bird. Grackles prefer to eat from the ground at bird feeders, making scattered seed an excellent choice of food for them. Grackles can be regularly seen foraging for insects, especially after a lawn trimming.

Grackles have a unique adaptation in the keel within their bill which allows them to crack and cut hard nuts or kernels. The keel projects downward from the horny palate and is sharper and more abrupt anterior. It extends below the level of the tomium and is used in a sawing motion to score open acorns or dried kernels. Larger adductor muscles within their jaw compared to those of other icterids make this adaptation even more useful for opening hard seeds and acorns.{{Cite journal|last=Beecher|first=William|date=1951|title=Adaptations for Food-Getting in the American Blackbirds|url=https://sora.unm.edu/sites/default/files/journals/auk/v068n04/p0411-p0440.pdf|journal=The Auk|volume=68|issue=4|pages=420–422|doi=10.2307/4080840|jstor=4080840}}

Along with some other species of grackles, the common grackle is known to practice "anting", rubbing insects on its feathers possibly to apply liquids such as formic acid secreted by the insects.

The grackle's song is particularly harsh, especially when these birds, in a flock, are calling. Songs vary from year-round chewink chewink to a more complex breeding season ooo whew, whew, whew, whew, whew call that gets faster and faster and ends with a loud crewhewwhew! It also occasionally sounds like a power line buzzing. The grackle can also mimic the sounds of other birds or even humans, though not as precisely as the mockingbird, which is known to share its habitat in the Southeastern United States.

File:Quiscalus quiscula - Common Grackle - XC99545.ogg

In the breeding season, males tip their heads back and fluff up feathers to display and keep other males away. This same behavior is used as a defensive posture to attempt to intimidate predators. Male common grackles are less aggressive toward one another, and more cooperative and social, than the larger boat-tailed grackle species.

The range of this bird expanded west as forests were cleared. In some areas, it is now considered a pest by farmers because of its large numbers and fondness for grain. Despite a currently robust population, a recent study by the National Audubon Society of data from the Christmas Bird Count indicated that populations had declined by 61% to a population of 73 million from historic highs of over 190 million birds.{{cite thesis |last=Strassburg |first=Matthew David |date=November 2011 |title=The evaluation of Christmas Bird Counts as an indicator of population trends and habitat selection in blackbirds and starlings |type=MSc |publisher=North Dakota State University |url=https://library.ndsu.edu/ir/bitstream/handle/10365/19385/Evaluation%20of%20Christmas%20Bird%20Counts%20as%20an%20Indicator%20of%20Population%20Trends%20and%20Habitat%20Selection%20in%20Blackbirds%20and%20Starlings.pdf?sequence=3&isAllowed=y |access-date=January 19, 2019}} As a result, it is now classified by the IUCN as Near Threatened.

Unlike many birds, the common grackle benefits from the expansion of human populations due to its resourceful and opportunistic nature. Common grackles are considered to be a serious threat to crops by some, and are notoriously difficult to control; this usually requires the use of hawks or similar large birds of prey.{{cite magazine| title=Murder Most Fowl| magazine=Time |url=http://www.time.com/time/health/article/0,8599,1582197,00.html| archive-url=https://web.archive.org/web/20070127194956/http://www.time.com/time/health/article/0,8599,1582197,00.html| url-status=dead| archive-date=January 27, 2007}}

Though the exact mechanism is poorly understood, several studies have examined the ability of the common grackle to interpret the Earth's magnetic field—or in this case, the variability of it. The common grackle (like most of its Quiscalus relatives) has been found to be attuned to a dynamic magnetic field to a scientifically significant degree.{{Cite journal|year=1992|title=Natural and Induced Remanent Magnetism in Birds|url=https://sora.unm.edu/sites/default/files/journals/auk/v109n01/p0043-p0056.pdf|journal=The Auk |volume=109|pages=43–56|doi=10.2307/4088265|jstor=4088265|via=Department of Geology and Geophysics, University of Oklahoma|last1=Schnell|first1=Gary D.|last2=Dubois|first2=Robert L.|last3=Hutchison|first3=Victor H.|issue=1}}

File:Juvenile and adult Common Grackle.jpg|Juvenile and adult together

Image:Common Grackle - markings.jpg|Iridescent back and head

Image:Common_Grackle - Iridescence.jpg|Iridescence in direct sunlight

Image:Common_Grackle_Leucistic.jpg|Partially leucistic/piebald

File:Baby grackle - Quiscalus quiscula.jpg|Chick

File:An albino grackle photographed in Peterborough Ontario 2012.jpg|An albino grackle in Peterborough, Ontario

File:Grackle IMG 3972.jpg|Male feeding in grass

File:Common_Grackle_(Quiscalus_quiscula).jpg|In Ontario, Canada

File:Common grackle on a wood piling, connecticut river - Flickr - TonySprezzatura.jpg|Common grackle on a wood piling, Connecticut River

{{Reflist}}

{{Wikispecies|Quiscalus quiscula}}

• {{InternetBirdCollection|common-grackle-quiscalus-quiscula|Common grackle}}
• [http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Common_Grackle.html Common grackle] - Cornell Lab of Ornithology
• [https://web.archive.org/web/20120710021754/http://stateofthebirds.audubon.org/CBID/ Audubon's Common Birds in Decline Report]
• [https://www.flmnh.ufl.edu/birds/florida-bird-sounds/ Florida bird sounds including the common grackle] - Florida Museum of Natural History
• {{VIREO|Common+Grackle|Common grackle}}

{{Taxonbar|from=Q1424486}}

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common grackle

Category:Birds of North America

Category:Birds of Canada

Category:Birds of the United States

common grackle

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common grackle

Category:Extant Pleistocene first appearances