Editing Peregrine falcon (section)

==Ecology and behaviour==
[[File:PeregrineTubercle.jpg|thumb|right|Closeup of head showing nostril tubercle]]
[[File:PeregrineFalconSilhouettes.svg|right|thumb|Silhouette in normal flight (left) and at the start of a stoop (right)]]
[[File:Peregrine_Falcon_(male).jpg|right|thumb|In its habitat in the [[Rann of Kutch]], [[Gujarat, India]]]]
The peregrine falcon lives mostly along [[mountain range]]s, [[river valley]]s, [[coastline]]s, and increasingly in [[cities]].<ref name=Ferguson-Lees2001/> In mild-winter regions, it is usually a permanent resident, and some individuals, especially adult males, will remain on the breeding territory. Only populations that breed in Arctic [[climate]]s typically migrate great distances during the northern winter.<ref name=DOI95/>

The peregrine falcon reaches faster speeds than any other animal on the planet when performing the stoop,<ref name=BBC/> which involves soaring to a great height and then diving steeply at speeds of over {{convert|320|km/h|mph|abbr=on|sigfig=2}}, hitting one wing of its prey so as not to harm itself on impact.<ref name=USFWS/> The air pressure from such a dive could possibly damage a bird's [[lung]]s, but small bony tubercles on a falcon's nostrils are theorized to guide the powerful airflow away from the nostrils, enabling the bird to breathe more easily while diving by reducing the change in air pressure.<ref name=Wisconsin/> 

To protect their eyes, the falcons use their [[nictitating membrane]]s (third eyelids) to spread tears and clear debris from their eyes while maintaining vision. The distinctive malar stripe or "moustache", a dark area of feathers below the eyes, is thought to reduce solar glare and improve contrast sensitivity when targeting fast moving prey in bright light condition; the malar stripe has been found to be wider and more pronounced in regions of the world with greater solar radiation supporting this solar glare hypothesis.<ref>{{Cite journal|last1=Vrettos|first1=Michelle|last2=Reynolds|first2=Chevonne|last3=Amar|first3=Arjun|title=Malar stripe size and prominence in peregrine falcons vary positively with solar radiation: support for the solar glare hypothesis|journal=Biology Letters|year=2021|volume=17|issue=6|pages=20210116|doi=10.1098/rsbl.2021.0116|pmc=8169203|pmid=34062086}}</ref> 

Peregrine falcons have a [[Flicker fusion threshold|flicker fusion frequency]] of 129&nbsp;Hz (cycles per second), very fast for a bird of its size, and much faster than mammals.<ref>{{cite journal |last1=Potier |first1=Simon |last2=Lieuvin |first2=Margaux |last3=Pfaff |first3=Michael |last4=Kelber| first4=Almut |date=January 2020 |title=How fast can raptors see? |journal=Journal of Experimental Biology |volume=223 |issue=Pt 1 |pages=jeb209031 |doi=10.1242/jeb.209031 |pmid=31822552 |s2cid=209313631 |doi-access=free }}</ref> A study testing the flight physics of an "ideal falcon" found a theoretical speed limit at {{Convert|400|km/h|mph|abbr=on}} for low-altitude flight and {{Convert|625|km/h|mph|abbr=on}} for high-altitude flight.<ref name="Tucker1998" /> In 2005, Ken Franklin recorded a falcon stooping at a top speed of {{convert|389|km/h|mi/h|0|abbr=on}}.<ref name="Harpole2005" />

The life span of peregrine falcons in the wild is up to 19 years 9 months.<ref>{{Cite web|url=https://www.allaboutbirds.org/guide/Peregrine_Falcon/overview|title=Peregrine Falcon Overview, All About Birds, Cornell Lab of Ornithology|website=www.allaboutbirds.org|at=Cool Facts|language=en|archive-url=https://web.archive.org/web/20190530221507/https://www.allaboutbirds.org/guide/Peregrine_Falcon/overview|archive-date=30 May 2019|access-date=30 May 2019}}</ref> Mortality in the first year is 59–70%, declining to 25–32% annually<!-- presumed; correct if needed --> in adults.<ref name=Snow1998/> Apart from such [[Human impact on the environment|anthropogenic]] threats as [[bird collision (disambiguation)|collision]] with human-made objects, the peregrine may be killed by larger [[hawk]]s and [[owl]]s.<ref name=Michigan/>

The peregrine falcon is [[host (biology)|host]] to a range of [[parasitism|parasites]] and [[pathogen]]s. It is a [[Vector (epidemiology)|vector]] for [[Avipoxvirus]], [[Newcastle disease virus]], [[Falconid herpesvirus 1]] (and possibly other [[Herpesviridae]]), and some [[mycoses]] and [[bacterial infection]]s. [[Endoparasite]]s include ''[[Plasmodium relictum]]'' (usually not causing [[malaria]] in the peregrine falcon), [[Strigeidae]] [[trematode]]s, ''[[Serratospiculum amaculata]]'' ([[nematode]]), and [[tapeworm]]s. Known peregrine falcon [[ectoparasite]]s are [[chewing lice]],{{refn|group=note|''Colpocephalum falconii'' which was described from specimens found on the peregrine falcon, ''Colpocephalum subzerafae'', ''Colpocephalum zerafae'' and ''Nosopon lucidum'' (all [[Menoponidae]]), ''Degeeriella rufa'' ([[Philopteridae]]), ''Laemobothrion tinnunculi'' ([[Laemobothriidae]]).<!-- -us is lapsus in ADW, originally from Birds of North America --> All are known from other ''Falco'' species too.<ref name=Potter2002/><ref name=Dalgleish2003/>}} ''[[Ceratophyllus garei]]'' (a [[flea]]), and [[Hippoboscidae]] flies (''[[Icosta nigra]]'', ''[[Ornithoctona erythrocephala]]'').<ref name=Potter2002/><ref name=Dalgleish2003/><ref name=Raidal1999/><ref name=Raidal2000/>

===Feeding===
[[File:Falco peregrinus on ship USFWS.jpg|thumb|An immature peregrine falcon eating its prey on the deck of a ship]]
[[File:Peregrine falcon with common teal kill (cropped and adjusted).jpg|thumb|An adult peregrine (''F. p. calidus'') consuming a [[Eurasian teal|common teal]] in [[Little Rann of Kutch]], Gujarat, India]]
The peregrine falcon's diet varies greatly and is adapted to available prey in different regions. However, it typically feeds on medium-sized birds such as [[Columbidae|pigeons and doves]], [[waterfowl]], [[gamebird]]s, [[songbird]]s, [[parrot]]s, [[seabird]]s, and [[wader]]s.<ref name=Beckstead2001/><ref name="auto">Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.</ref> Worldwide, it is estimated that between 1,500 and 2,000 bird species, or roughly a fifth of the world's bird species, are predated somewhere by these falcons. The peregrine falcon preys on the most diverse range of bird species of any raptor in North America, with over 300 species and including nearly 100 [[shorebird]]s.<ref name="Sherrod1978" /> Its prey can range from {{convert|3|g|oz|adj=on|abbr=on}} [[hummingbird]]s (''[[Selasphorus]]'' and ''[[Archilochus (bird)|Archilochus]]'' ssp.) to the {{convert|3.1|kg|lb|adj=on|abbr=on}} [[sandhill crane]], although most prey taken by peregrines weigh between {{convert|20|g|oz|abbr=on}} (small [[passerine]]s) and {{convert|1100|g|lb|abbr=on}} ([[duck]]s, [[Anser (bird)|geese]], [[loon]]s, [[gull]]s, [[Tetrao|capercaillie]]s, [[Lagopus|ptarmigan]]s and other [[grouse]]).<ref name="bna" /><ref name="Brown1986" /><ref name="auto"/><ref>{{cite web | url=https://animaldiversity.org/accounts/Falco_peregrinus/ | title=Falco peregrinus (Peregrine falcon) | website=[[Animal Diversity Web]] }}</ref> Smaller [[hawk]]s (such as [[sharp-shinned hawk]]s) and [[owl]]s are regularly predated, as well as smaller falcons such as the [[American kestrel]], [[Merlin (bird)|merlin]] and, rarely, other peregrines.<ref name="Hogan2010" /><ref name="Klem1985" /><ref name="auto"/>

In urban areas, where it tends to nest on tall buildings or bridges, it subsists mostly on a variety of pigeons.<ref>{{cite book |last1=Ball |last2=Ferrand Jr. |first1=John |first2=John |date=1994 |title=National Audubon Society Field Guide to North American Birds |location=USA |publisher=Knopf |page=440 |isbn=0-679-42852-6}}</ref> Among pigeons, the [[rock dove]] or [[feral pigeon]] comprises 80% or more of the dietary intake of peregrines. Other common city birds are also taken regularly, including [[mourning dove]]s, [[common wood pigeon]]s, [[common swift]]s, [[northern flicker]]s, [[eurasian collared dove]]s, [[common starling]]s, [[American robin]]s, [[common blackbird]]s, and [[corvid]]s such as [[magpie]]s, [[jay]]s or [[Carrion crow|carrion]], [[House crow|house]], and [[American crow]]s.<ref name=Drewitt2008/><ref>{{cite web | url=https://www.peregrinefund.org/explore-raptors-species/falcons/peregrine-falcon | title=Peregrine Falcon &#124; the Peregrine Fund }}</ref> Coastal populations of the large subspecies ''pealei'' feed almost exclusively on [[seabird]]s.<ref name=Terres1991/> In the Brazilian [[mangrove]] swamp of [[Cubatão]], a wintering falcon of the subspecies ''tundrius'' was observed successfully hunting a juvenile [[scarlet ibis]].<ref name=Olmos2003/>
[[File:Peregrine Falcon imported from iNaturalist photo 243839915 on 3 December 2024.jpg|thumb|Diving on a flock of [[common starling]] in [[Rome]]]]
Among mammalian prey species, [[bat]]s in the genera ''[[Eptesicus]]'', ''[[Myotis]]'', ''[[Pipistrellus]]'' and ''[[Tadarida]]'' are the most common prey taken at night.<ref>Mikula, P., Morelli, F., Lučan, R. K., Jones, D. N., & Tryjanowski, P. (2016). Bats as prey of diurnal birds: a global perspective. Mammal Review.</ref> Though peregrines generally do not prefer terrestrial mammalian prey, in [[Rankin Inlet]], peregrines largely take [[northern collared lemming]]s (''Dicrostonyx groenlandicus'') along with a few [[Arctic ground squirrel]]s (''Urocitellus parryii'').<ref>Bradley, Mark, and Lynn W. Oliphant. "The diet of Peregrine Falcons in Rankin Inlet, Northwest Territories: an unusually high proportion of mammalian prey." The Condor 93.1 (1991): 193–197.</ref> Other small mammals including [[shrew]]s, [[mouse|mice]], [[rat]]s, [[vole]]s, and [[squirrel]]s are more seldom taken.<ref name=Drewitt2008/><ref name =Ratcliffe>Ratcliffe, Derek. The peregrine falcon. A&C Black, 2010.</ref>  Peregrines occasionally take [[rabbit]]s, mainly young individuals and juvenile [[hare]]s.<ref name =Ratcliffe/><ref name =Pagel.>Pagel, J. E., & Schmitt, N. J. (2013). American Marten Remains Within Peregrine Falcon Prey Sample in Yellowstone National Park. Journal of Raptor Research, 47(4), 419–420.</ref> Additionally, remains of [[red fox]] kits and adult female [[American marten]] were found among prey remains.<ref name =Pagel./> Insects and reptiles such as small [[snake]]s make up a small proportion of the diet, and [[salmonidae|salmonid fish]] have been taken by peregrines.<ref name=Beckstead2001/><ref name=Ratcliffe/><ref>{{cite web|url=https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/documents/ogatt/Falco_peregrinus%20-%20Peregrine%20Falcon.pdf |first=Jerome |last=Gunness|date=2012|title=''Falco peregrinus'' (Peregrine Falcon)|work=The Online Guide to the Animals of Trinidad and Tobago|publisher=University of the West Indies}}</ref>

The peregrine falcon hunts most often at dawn and dusk, when prey are most active, but also nocturnally in cities, particularly during migration periods when hunting at night may become prevalent. Nocturnal migrants taken by peregrines include species as diverse as [[yellow-billed cuckoo]], [[black-necked grebe]], [[virginia rail]], and [[common quail]].<ref name=Drewitt2008/> The peregrine requires open space in order to hunt, and therefore often hunts over open water, [[marsh]]es, [[valley]]s, fields, and [[tundra]], searching for prey either from a high perch or from the air.<ref name=Ehrlich1992/> Large congregations of migrants, especially species that gather in the open like shorebirds, can be quite attractive to a hunting peregrine. Once prey is spotted, it begins its stoop, folding back the tail and wings, with feet tucked.<ref name=Terres1991/> Prey is typically struck and captured in mid-air; the peregrine falcon strikes its prey with a clenched foot, stunning or killing it with the impact, then turns to catch it in mid-air.<ref name=Ehrlich1992/> If its prey is too heavy to carry, a peregrine will drop it to the ground and eat it there. If they miss the initial strike, peregrines will chase their prey in a twisting flight.<ref name=Treleaven1980/>

Although previously thought rare, several cases of peregrines contour-hunting, i.e., using natural contours to surprise and ambush prey on the ground, have been reported and even rare cases of prey being pursued on foot. In addition, peregrines have been documented preying on chicks in nests, from birds such as kittiwakes.<ref name="Collins2014" /> Prey is plucked before consumption.<ref name="Wisconsin" /> A 2016 study showed that the presence of peregrines benefits non-preferred species while at the same time causing a decline in its preferred prey.<ref>{{cite journal |id={{Gale|A468335744}} {{ProQuest|1824544665}} |last1=Tornberg |first1=Risto |last2=Korpimaki |first2=Veli-Matti |last3=Rauhala |first3=Pentti |last4=Rytkonen |first4=Seppo |title=Peregrine Falcon (Falco peregrinus) may affect local demographic trends of wetland bird prey species |journal=Ornis Fennica |date=1 July 2016 |volume=93 |issue=3 |pages=172–186 |doi=10.51812/of.133899 |doi-access=free }}</ref> As of 2018, the fastest recorded falcon was at 242&nbsp;mph (nearly 390&nbsp;km/h). Researchers at the University of Groningen in the Netherlands and at Oxford University used 3D computer simulations in 2018 to show that the high speed allows peregrines to gain better maneuverability and precision in strikes.<ref name="FALCON">{{Cite web|last=McMillan|first=Fiona|title=Falcon Attack: How Peregrine Falcons Maneuver At Nearly 225 MPH|url=https://www.forbes.com/sites/fionamcmillan/2018/04/13/falcon-attack-how-peregrine-falcons-maneuver-at-nearly-225-mph/|access-date=2023-02-12|website=Forbes
| date = 13 April 2018
|language=en}}</ref>

===Reproduction===
[[File:Faucon pelerin 7 mai.jpg|thumb|right|At nest, France]]
[[File:Falco peregrinus MWNH 0671.JPG|thumb|Egg, [[Museum Wiesbaden]]]]
The peregrine falcon is sexually mature at one to three years of age, but in larger populations they breed after two to three years of age. A pair [[mates for life]] and returns to the same nesting spot annually. The courtship flight includes a mix of aerial acrobatics, precise spirals, and steep dives.<ref name=Potter2002/> The male passes prey it has caught to the female in mid-air. To make this possible, the female actually flies upside-down to receive the food from the male's talons.{{Citation needed|date=April 2025}}

During the breeding season, the peregrine falcon is territorial; nesting pairs are usually more than {{convert|1|km|mi|abbr=on}} apart, and often much farther, even in areas with large numbers of pairs.<ref name=Blood2001/> The distance between nests ensures sufficient food supply for pairs and their chicks. Within a breeding territory, a pair may have several nesting ledges; the number used by a pair can vary from one or two up to seven in a 16-year period.{{Citation needed|date=April 2025}}

The peregrine falcon nests in a scrape, normally on cliff edges.<ref>{{cite web |last1=Kaufman |first1=Kenn |title=Peregrine Falcon |url=https://www.audubon.org/field-guide/bird/peregrine-falcon |website=[[Audubon (magazine)|Audubon]] |date=13 November 2014 |publisher=National Audubon Society |access-date=12 June 2019}}</ref> The female chooses a nest site, where she scrapes a shallow hollow in the loose soil, sand, gravel, or dead vegetation in which to lay eggs. No nest materials are added.<ref name=Potter2002/> Cliff nests are generally located under an overhang, on ledges with vegetation. South-facing sites are favoured.<ref name=Terres1991/> In some regions, as in parts of [[Australia]] and on the west coast of northern North America, large tree hollows are used for nesting. Before the demise of most European peregrines, a large population of peregrines in central and western Europe used the disused nests of other large birds.<ref name=Beckstead2001/> In remote, undisturbed areas such as the Arctic, steep slopes and even low rocks and mounds may be used as nest sites. In many parts of its range, peregrines now also nest regularly on tall buildings or bridges; these human-made structures used for breeding closely resemble the natural cliff ledges that the peregrine prefers for its nesting locations.<ref name=White94/><ref name=Blood2001/>

The pair defends the chosen nest site against other peregrines, and often against [[raven]]s, [[heron]]s, and [[gull]]s, and if ground-nesting, also such mammals as [[fox]]es, [[wolverine]]s, [[felid]]s, [[bear]]s, [[wolf|wolves]], and [[mountain lion]]s.<ref name=Blood2001/> Both nests and (less frequently) adults are predated by larger-bodied raptorial birds like [[eagle]]s, large [[Horned owl|owls]], or [[gyrfalcon]]s. The most serious predators of peregrine nests in North America and Europe are the [[great horned owl]] and the [[Eurasian eagle-owl]]. When reintroductions have been attempted for peregrines, the most serious impediments were these two species of owls routinely picking off nestlings, fledglings and adults by night.<ref name=Walton1988/><ref name=Brambilla2006/> Peregrines defending their nests have managed to kill raptors as large as [[golden eagle]]s and [[bald eagle]]s (both of which they normally avoid as potential predators) that have come too close to the nest by ambushing them in a full stoop.<ref name=bna2/> In one instance, when a [[snowy owl]] killed a newly fledged peregrine, the larger owl was in turn killed by a stooping peregrine parent.<ref name=Voous1988/>

The date of egg-laying varies according to locality, but is generally from February to March in the [[Northern Hemisphere]], and from July to August in the [[Southern Hemisphere]], although the Australian subspecies ''F. p. macropus'' may breed as late as November, and [[equator]]ial populations may nest anytime between June and December. If the eggs are lost early in the nesting season, the female usually lays another clutch, although this is extremely rare in the Arctic due to the short summer season. Generally three to four eggs, but sometimes as few as one or as many as five, are laid in the scrape.<ref name=Peterson/> The eggs are white to buff with red or brown markings.<ref name=Peterson/> They are incubated for 29 to 33 days, mainly by the female,<ref name=Terres1991/> with the male also helping with the incubation of the eggs during the day, but only the female incubating them at night. The average number of young found in nests is 2.5, and the average number that fledge is about 1.5, due to the occasional production of infertile eggs and various natural losses of nestlings.<ref name=White94/><ref name=Wisconsin/><ref name=Michigan/>

After hatching, the chicks (called "{{linktext|eyas}}es"<ref name=raptorresource/>) are covered with creamy-white down and have disproportionately large feet.<ref name=Blood2001/> The male (called the "{{linktext|tiercel}}") and the female (simply called the "falcon") both leave the nest to gather prey to feed the young.<ref name=Wisconsin/> The hunting territory of the parents can extend a radius of {{convert|19|to|24|km|mi|abbr=on}} from the nest site.<ref name=Towry1987/> Chicks [[fledge]] 42 to 46 days after hatching, and remain dependent on their parents for up to two months.<ref name=Snow1998/>