flight zone

Animals faced with approaching predators must decide at which distance to initiate their flight, and they are expected to do so in a way that maximizes their fitness. As flight has both costs (including lost opportunity) and benefits, there will be in general an optimal flight initiation distance, defined as the first point in a predator's approach at which the benefit of flight exceeds the cost. The benefit of

flight is equivalent to the cost of remaining in place or, in other words, to the risk of capture. The size of the flight zone can therefore vary according to circumstances. However, it has been shown in burrowing owls that individuals showed high repeatability in their FID.{{cite journal | last1 = Carrete | first1 = M. | last2 = Tella | first2 = J.L. | year = 2009 | title = Individual consistency in flight initiation distances in burrowing owls: a new hypothesis on disturbance-induced habitat selection | journal = Biology Letters | volume = 6 | issue = 2| pages = 167–170 | doi = 10.1098/rsbl.2009.0739 | pmid = 19864278 | pmc = 2865052 | doi-access = free }}

• Behaviour of the threat: In horned lizards, FID decreased as the distance between a turning predator and prey increased, but was greater when the predator turned toward than away from the fleeing animal.{{cite web|url=http://www.academicconcepts.net/concepts/414/horned_lizard.htm|author=Cooper, W.E.|year=2000|title=Plesiomorphic escape decisions in cryptic horned lizards (Phrynosoma) having highly derived antipredatory defenses|access-date=20 April 2013}} The FID and alert response of American robins to approaching humans was investigated; the greatest FID was when the approaching person was not on paths and was looking at the birds, while the lowest FID occurred when the person was on a path and not looking at the robins. The authors suggested this indicated that they use gaze direction to assess risk.{{cite journal | last1 = Eason | first1 = P.K. | last2 = Sherman | first2 = P.T | last3 = Rankin | first3 = O. | last4 = Coleman | first4 = B. | year = 2006 | title = Factors affecting flight initiation distance in American robin | journal = The Journal of Wildlife Management | volume = 70 | issue = 6| pages = 1796–1800 | doi = 10.2193/0022-541x(2006)70[1796:fafidi]2.0.co;2 | s2cid = 85926285 }}
• Social: In lizards, FID was shorter during social encounters than when they were solitary. and FID was shorter in female lizards when they were interacting with males than when they were alone; it was also shorter in males interacting with either sex.{{cite journal | last1 = Cooper | first1 = W.E. | year = 2009 | title = Flight initiation distance decreases during social activity in lizards (Sceloporus virgatus) | journal = Behavioral Ecology and Sociobiology | volume = 63 | issue = 12| pages = 1765–1771 | doi = 10.1007/s00265-009-0799-1 | bibcode = 2009BEcoS..63.1765C | s2cid = 24549272 }}
• Distance to refuge: Gray squirrels (Sciurus carolinensis) typically run to the nearest tree to escape from predators. As the risk of capture increases with distance from the refuge tree, squirrels feeding far from trees should have greater FID than those feeding closer by. Confirming this, FID in response to a motorized model predator (a cat) increased as distance to refuge increased.{{cite journal | last1 = Dill | first1 = L.M. | last2 = Houtman | first2 = R. | year = 1989 | title = The influence of distance to refuge on flight initiation distance in the gray squirrel (Sciurus carolinensis) | url = https://www.sfu.ca/biology/faculty/dill/publications/dandH.pdf | journal = Canadian Journal of Zoology | volume = 67 | issue = 1 | pages = 233–235 | doi = 10.1139/z89-033 | bibcode = 1989CaJZ...67..233D }} Burrowing Owls breeding in territories far from roads showed larger FIDs than individuals breeding closer to roads and mated owls showed similar FIDs. Individual owls showed high repeatability in their FID.
• Training and learning: The size of the flight zone can depend upon the tameness or level of habituation of the animal. Completely tame animals have no flight zone for humans; that is, they will allow a person to approach and touch them. Wild, feral, and unbroken animals can have very large flight zones.

Wildlife managers often use ED and FID to develop set-back distances to reduce human impacts on wildlife,{{cite journal |author=Fernandez-Juricic E. |author2=Jimenez M. D. |author3=Lucas E. |year=2001 |title=Alert distance as an alternative measure of bird tolerance to human disturbance- implications for park design |journal=Environmental Conservation |volume=28 |issue=3 |pages=263–269 |doi=10.1017/S0376892901000273 |bibcode=2001EnvCo..28..263F |s2cid=44189097 |url=http://www.bio.purdue.edu/people/faculty/faculty_files/publications/36199_1492081880.PDF |access-date=4 September 2012}}{{cite journal |author=Blumstein D. T. |date=Oct 2003 | title=Flight-Initiation Distance in Birds Is Dependent on Intruder Starting Distance |journal=The Journal of Wildlife Management |volume=67 |issue=4 |pages=852–857 |publisher=Allen Press |url=https://www.eeb.ucla.edu/Faculty/Blumstein/pdf%20reprints/BlumsteinJWM2003.pdf |access-date=4 September 2012 |doi=10.2307/3802692|jstor=3802692 }}{{cite journal |author=Bentrup G. |year=2008 |title=Conservation buffers: design guidelines for buffers, corridors, and greenways. |journal=Gen. Tech. Rep. |volume=SRS-109 |publisher=USDA, Forest Service, Southern Research Station. |location=Asheville, NC }} both in wildlife refuges, and, e.g., in planning areas for outdoor recreation.[http://www.bio.purdue.edu/people/faculty/faculty_files/publications/36199_1492081880.PDF Alert distance as an alternative measure of bird tolerance to human disturbance: implications for park design]

These measures are also important in birding and nature photography.

The FID in multiple species differs from rural to urban areas.{{cite journal|last1=Møller|first1=A. P.|last2=Tryjanowski|first2=P|last3=Díaz|first3=M|last4=Kwieciński|first4=Z|last5=Indykiewicz|first5=P|last6=Mitrus|first6=C|last7=Golawski|first7=A|last8=Polakowski|first8=M|date=2015|title=Urban habitats and feeders both contribute to flight initiation distance reduction in birds|journal=Behavioral Ecology|volume=26|issue=3|pages=861–865|doi=10.1093/beheco/arv024|doi-access=free}} A study by Møller et al. examined 811 FIDs from 37 species of birds and determined that the FID of birds in urban areas is reduced, compared to the FID of birds in rural areas. Urbanization of birds has also been shown to correlate with changes in stress physiology and anti predator behaviour. Similarly, a circumtropical study that studied escape responses of 10,249 bird individuals from 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia found that FIDs are smaller in urban than rural habitats and decline also with increasing human footprint.{{cite journal |vauthors=Mikula P, Tomášek O, Romportl D, Aikins TK, Avendaño JE, Braimoh-Azaki BD, Chaskda A, Cresswell W, Cunningham SJ, Dale S, Favoretto GR, Floyd KS, Glover H, Grim T, Henry DA, Holmern T, Hromada M, Iwajomo SB, Lilleyman A, Magige FJ, Martin RO, Maximiano MF, Nana ED, Ncube E, Ndaimani H, Nelson E, van Niekerk JH, Pienaar C, Piratelli AJ, Pistorius P, Radkovic A, Reynolds C, Røskaft E, Shanungu GK, Siqueira PR, Tarakini T, Tejeiro-Mahecha N, Thompson ML, Wamiti W, Wilson M, Tye DR, Tye ND, Vehtari A, Tryjanowski P, Weston MA, Blumstein DT, Albrecht T |date=2023 |title=Bird tolerance to humans in open tropical ecosystems |journal=Nature Communications |volume=14 |page=2146 |doi=10.1038/s41467-023-37936-5 |url=https://www.nature.com/articles/s41467-023-37936-5 |hdl=10023/27452 |hdl-access=free }} This may be due to a number of factors differing in rural vs urban areas, such as; difference in predator communities, length of exposure time to humans, relative abundance of humans, and the presence/abundance of food (bird-feeders in winter for example). Wildlife managers must adjust buffer zones depending on urban/rural environments. However, a situation may differ between taxa - a study on dragonflies and damselflies (Odonata) found that while urbanization level did not directly affect their escape behavior, escape responses of Odonata were delayed in areas with high human activity.{{Cite journal|vauthors=Mikula P, Czechowski P, Dubicka-Czechowska A, Jerzak L, Menzel A, Tryjanowski P |date=2025 |title=Understanding antipredator strategies of insects: Human presence and escape behaviour in Odonata |journal=Ecological Entomology |doi=10.1111/een.13430 |doi-access=free }}

Some physical characteristics are very important to determine an animal's FID.{{cite journal|last1=Møller|first1=A. P.|last2=Erritzøe|first2=J.|date=2013|title=Predator-prey interactions, flight initiation distance and brain size|journal=Journal of Evolutionary Biology|volume=26|issue=1|pages=23–42|doi=10.1111/jeb.12272|pmid=25990564|s2cid=41897304}} Eye size and brain size have a role in determining the FID. FID in 107 species of birds was studied in relation to eye size and brain size and was shown that FID increases with larger eyes and decreases with larger brains. Larger eyes mean that predators can be detected from further away and thus the FID would be larger compared to smaller eyes. Larger brains decrease the FID compared to smaller brains, since they can better process the intent of predators and can delay their flight response for as long as possible.

FID can be highly variable, but it can also be viewed as a species-specific trait. A study conducted using eight species of shorebirds at six different sites in Australia was conducted to determine if FID was species specific. It was demonstrated that while both the species and the site influenced the FID, there was no significant interaction between them. This indicates that FID is species-specific, and while sites do influence the FID of a species, the average FID is a good reference for wildlife managers to use when creating buffer zones.

While escape distance has been generally used as a measure of tolerance, other changes in animal behavior in presence of humans, such as increased vigilance time at the cost of decreased feeding time, may have significant overall impact on wildlife. Therefore, it is suggested that a more conservative measure, namely, the alert distance, should be used in determining minimum approaching distance. The latter typically adds a certain buffer distance to the given tolerance measure.{{r|nacunledu}}

The flight zone is an important principle for herding, working, and mustering livestock. An animal can be stimulated to move simply by skirting its flight zone, and the animal will move in the desired direction according to the point of balance. The point of balance is usually located at the animal's shoulder according to their wide angled vision. An overstimulated animal will have a larger flight zone, for example an excited or scared animal.{{cite web|last=Grandin|first=Temple|title=Behavioural Principles of Livestock Handling|url=http://www.grandin.com/references/new.corral.html|work=Vision, Hearing, and Handling methods in Cattle and Pigs|publisher=American Registry of Professional Animal Scientists|access-date=7 October 2013}} A Cumulative Flight Zone is formed when animals move in a herd. In this situation the lead animal's and the following animals' Points of Balance, within the cumulative flight zone, must both be crossed to entice movement.

The flight distance during handling is usually 1.5 to 7.6 m for beef cattle raised in a feeding operation and up to 30 m on mountain ranges.{{cite journal | last1 = Grandin | first1 = T | year = 1980 | title = Observations of cattle behavior applied to the design of cattle-handling facilities | journal = Appl. Anim. Ethol. | volume = 6 | pages = 19–31 | doi = 10.1016/0304-3762(80)90091-7 }} Brahman cattle have a larger flight zone than most English breeds.{{cite journal | last1 = Grandin | first1 = T | year = 1978 | title = Observations of the spatial relationships between people and cattle during handling | journal = Proc. Western Sect., Am. Soc. Anim. Sci. | volume = 29 | pages = 76–79 }} The flight zone can be thought of as the animal's personal space. The size of the flight zone is determined by the tameness of the animal; the more domesticated an animal, the smaller the zone. Fully tame animals have no flight zone.{{cite web|last=Grandin|first=Temple|title=Behavioural Principles of Livestock Handling|url=http://www.grandin.com/references/new.corral.html|work=Vision, Hearing, and Handling methods in Cattle and Pigs|publisher=American Registry of Professional Animal Scientists|access-date=7 October 2013}}

The flight zones in cattle vary depending on the situation they are experiencing.{{cite book|title=Cow talk: understanding dairy cow behaviour to improve their welfare on Asian farms|last1=Moran|first1=J|last2=Doyle|first2=R|date=2015|publisher=CSIRO Publishing|location=Clayton South, Vic|pages=48–49}} Novel situations increase their flight zone, while accustomed stimuli will decrease their flight zone. The flight zone is larger in the front than behind, due to the majority of their senses pointing forward. As the animal becomes more relaxed in a situation or with a person its flight zone will reduce. The cow's prior experiences with humans has also been shown to affect their flight zone. Cows with positive handling experiences were shown to have smaller flight zones than those with negative handling experiences.

Studies with sheep indicated that animals confined in a narrow alley had a smaller flight zone compared to animals confined in a wider alley.{{cite journal | last1 = Hutson | first1 = G.D. | year = 1982 | title = Flight distance in Merino sheep | journal = Animal Production | volume = 35 | issue = 2| pages = 231–235 | doi = 10.1017/s0003356100027409 }}

Handlers sometimes make the mistake of deeply invading the flight zone when animals are being driven down an alley or into an enclosed area such as a crowd pen. If the handler deeply penetrates the flight zone, the animals may turn back and run over them in an attempt to escape.{{cite web|url=http://www.grandin.com/references/new.corral.html|title=Behavioral principles of livestock handling|author=Grandin T.|year=1989|access-date=22 April 2013}} Confining a livestock animal in a crush (chute) or alley can make it feel more secure and thus reduce the size of the flight zone; however, it does not eliminate the flight zone. An animal in a livestock raceway or alley that feels threatened may panic and injure itself or other animals.{{cite web|author1=Chambers, P.G.|author2=Grandin, T.|author3=Heinz, G.|author4=Srisuvan, T.|title=Guidelines for Humane Handling, Transport and Slaughter of Livestock|year=2001|publisher=Food and Agriculture Organization of the United Nations – Regional Office for Asia and the Pacific|url=http://www.fao.org/docrep/003/x6909e/x6909e07.htm|access-date=22 April 2013}} If handlers lean over fences around animals they penetrate the "zone of safety" and may cause the animals to rear.Grandin, T. (1983). Handling and processing feedlot cattle. In: G.B. Thompson and C.C. O'Mary (Eds) The Feedlot, Lea & Febiger, Philadelphia. pp. 213–235

Animals have a tendency to move in the opposite direction when their handler walks deep into their flight zone. By crossing an animal's point of balance, within the flight zone, a handler can move the herd in a particular direction and control their speed of movement. For example, crossing the point of balance from front to back will move the animal forwards, while the opposite is also true. The handler's pace should always reflect the animal's speed when herding. Additionally, pressure should be alternated on the flight zone to reduce stress. Constant pressure should never be applied.

If animals turn to face the handler he or she is considered to be no longer penetrating the flight zone.

It is important that a handler does not pursue any struggling animals as this will cause undue stress. Instead the animal should be allowed to return to the group as animals naturally have herd instincts, and will follow the group's leader. A good herding practice applying this is the movement of animals through a race by maintaining a steady flow of animals, not herding in groups, this allows new animals to follow the leader calmly.{{cite web|last=Grandin|first=Temple|title=Understanding Flight Zones and Point of Balance|url=https://proway.com.au/working-with-proway/principles-of-design/|access-date=September 30, 2020|website=ProWay|publisher=ProWay Livestock Equipment|df=dmy-all}} When yarded, animals should always have room to turn away from the handler to reduce stress. Minimal stress prevents injury to the animal and maintains good production, such as increased quality of meat and improved muscle and fat scores.

Appropriate frequent penetration of the flight zone can train the animals to minimise their flight zone to the handler.

Poor husbandry skills including over penetration of the flight zone results in the following behaviours: stress, panic, aggression, bolting, prey behaviour, charging, fainting, sickness and self-inflicted damage. Rough handling, such as constant flight zone pressure, can raise the heart rate of an animal. These factors are all reflective of the General Adaptation Syndrome.

The general adaptation syndrome (GAS) is a three-phase response to stress in animals.

• The first phase is the fight or flight response – the animal flight zone is included in this. Over penetration of the animal flight zone causes stimulation of the sympathetic nervous system (SNS). The SNS produces localised adjustments and responses; this includes the excretion of large quantities of epinephrine from the medulla of the adrenal gland.{{cite web|last=Loewy|first=Arthur|title=Human Nervous System|url=http://www.britannica.com/EBchecked/topic/409709/human-nervous-system/75584/Sympathetic-nervous-system#ref942317|publisher=Britannica|access-date=7 October 2013}} Epinephrine is commonly known as adrenaline. Adrenaline increases the supply of oxygen to vital organs and decreases supply to others.{{cite web|last=Unknown|first=Unknown|title=General Adaptation Syndrome|url=http://library.thinkquest.org/C0123421/gas.htm|publisher=Oracle Education Foundation|access-date=7 October 2013|archive-url=https://web.archive.org/web/20131019101833/http://library.thinkquest.org/C0123421/gas.htm|archive-date=19 October 2013|df=dmy-all}} Frequent subjection to fight or flight situations causes severe endocrine disorders.
• The second phase is Adaptation and Resistance. It is the idea that recurring subjection builds natural immunity, and common handler movement and herding minimises an animals flight zone.
• The third phase is Exhaustion. Strong, constant and over frequent stimulation of an animals flight zone may lead to death, decreases production and lower quality of life. According to the GAS, a full recovery from exhaustion is possible over time.

Sample escape distances (mostly mean) from humans:

Birds of Europe

File:Camera and telescopic lens on a tripod -onithology-7July2007.jpg and birdwatchers sometimes use digiscoping equipment, allowing them to take pictures from long distances.]]

{{Col-begin}}

{{Col-break}}

Birds of North America{{r|nacunledu}}

{{Col-break}}

Mammals of North America{{r|nacunledu}}

{{col-end}}

File:Fleeing Blackbird.jpg]]

Escape distance may differ significantly depending on many circumstances. Body size is the best known general factor influencing interspecies differences. Very frequently large species are more timid than small species, because size affects how rapidly a bird can take off.{{r|Bregnballe09|Laursen05}} Surprisingly, an analysis of hundreds of studies found that larger birds are more tolerant of humans, despite substantial research that shows larger animals are less tolerant of humans.

Among the affecting factors:

• Species{{r|Laursen05|Ruddock07|Blumstein03|Fernandez01|Bregnballe09|Gotzman79}} – for example mallard Anas platyrhynchos has shorter ED than pintail Anas acuta{{r|Laursen05}}.
• Age – young birds are less shy, for example dunlin Calidris alpina {{citation needed|date=September 2012}})
• Habituation to walking people.{{r|Laursen05}} Mallards Anas platyrhynchos or Canada Geese Branta canadensis are less shy in a park than somewhere in the wild. Tits and Nuthatches near the feeder or in the park are less shy than in the wild.
• Season. For example, wintering bullfinches Pyrrhula pyrrhula have shorter EDs than breeding ones.{{r|Gotzman79}}
• Origin of birds – sometimes wintering birds from the north, perhaps not knowing people, are less shy than native, for example nutcracker Nucifraga caryocatactes{{r|Gotzman79}}
• Given bird individual{{citation needed|date=September 2012}}
• Color of clothes of an observer and observer's behaviour{{r|Gotzman79}}
• Hunting status – quarry species have longer EDs than non-quarry, increasing during hunting season or after days with hunting.{{r|Laursen05|Bregnballe09}}
• Flock size{{r|Bregnballe09}}
• Flock composition – for example birds in mixed flocks of mallard Anas platyrhynchos and teal Anas crecca react at longer distances than those in single species flocks for either species.{{r|Bregnballe09}} Or dunlin Calidris alpina in flocks with other waders.{{r|Gotzman79}}
• Visibility of the stimulus to the birds{{r|Bregnballe09}}
• Wind force{{r|Laursen05}}
• Vegetation height{{r|Bregnballe09}}

It is shown that the Lizard Urosaurus ornatus where different colored males have differing FID values due to differences in hormonal levels.

• Birdwatching
• Digiscoping
• Fight-or-flight response
• Herding
• Nature photography
• Personal space
• Wildlife management
• Wildlife photography

{{reflist}}

• {{cite journal | last1 = Cooper | first1 = W.E. | last2 = Frederick | first2 = W.G. | year = 2007 | title = Optimal flight initiation distance | journal = Journal of Theoretical Biology | volume = 244 | issue = 1| pages = 59–67 | doi = 10.1016/j.jtbi.2006.07.011 | pmid = 16949619 | bibcode = 2007JThBi.244...59C }}

{{Ethology}}

Category:Birdwatching

Category:Ethology

Category:Fear

Category:Livestock

Category:Nature photography