The Peregrine Falc on
(Falco peregrinus), also known simply as the Peregrine,and historically
as the "Duck Hawk" in North America, is a cosmopolitan bird of prey in
the family Falconidae. It is a large, crow-sized falcon, with a
blue-gray back, barred white underparts, and a black head and
"moustache". It can reach speeds over 322 km/h (200 mph) in a dive,
making it the fastest animal in the world. As is common with bird-eating
raptors, the female is much bigger than the male. Experts recognize
1719 subspecies, which vary in appearance and range; there is
disagreement over whether the distinctive Barbary Falcon is a subspecies
or a distinct species.
The Peregrine's breeding range includes land regions from the Arctic
tundra to the Tropics. It can be found nearly everywhere on Earth,
except extreme polar regions, very high mountains, and most tropical
rainforests; the only major ice-free landmass from which it is entirely
absent is New Zealand. This makes it the world's most widespread bird of
prey. Both the English and scientific names of this species mean
"wandering falcon", referring to the migratory habits of many northern
populations.
While its diet consists almost exclusively of medium-sized birds, the
Peregrine will occasionally hunt small mammals, small reptiles or even
insects. It reaches sexual maturity at one year, and mates for life. It
nests in a scrape, normally on cliff edges or, in recent times, on tall
human-made structures. The Peregrine Falcon became an endangered species
in many areas due to the use of pesticides, especially DDT. Since the
ban on DDT from the beginning of the 1970s onwards, the populations
recovered, supported by large scale protection of nesting places and
releases to the wild.
The Peregrine Falcon has a body length of 34 to 58 centimetres (1323
in) and a wingspan of around 80 to 120 centimetres (3147 in).[5][10]
The male and female have similar markings and plumage, but as in many
birds of prey the Peregrine Falcon displays marked reverse sexual
dimorphism in size, with the female measuring up to 30 percent larger
than the male.[11] Males weigh 440750 g, and the noticeably larger
females weigh 9101500 g; for variation in weight between subspecies,
see under that section below.
The back and long, pointed wings of the adult are usually bluish
black to slate gray with indistinct darker barring (see "Subspecies"
below); the wingtips are black.[10] The underparts are white to rusty
and barred with thin clean bands of dark brown or black.[12] The tail,
colored like the back but with thin clean bars, is long, narrow and
rounded at the end with a black tip and a white band at the very end.
The top of the head and a "mustache" along the cheeks are black,
contrasting sharply with the pale sides of the neck and white throat.The
cere is yellow, as are the feet, and the beak and claws are black.The
upper beak is notched near the tip, an adaptation which enables falcons
to kill prey by severing the spinal column at the neck.[4][5][6] The
immature bird is much browner with streaked, rather than barred,
underparts, and has a pale bluish cere.
Taxonomy and systematics
This species was first described by Marmaduke Tunstall in his 1771
Ornithologia Britannica under its current binomial name.The scientific
name Falco peregrinus, means "wandering falcon" in Latin. Indeed, the
species' common name refers to its wide-ranging flights in most European
languages.The Latin term for falcon, falco, is related to falx, the
Latin word meaning sickle, in reference to the silhouette of the
falcon's long, pointed wings in flight.
The Peregrine Falcon belongs to a genus whose lineage includes the
hierofalcons and the Prairie Falcon (F. mexicanus). This lineage
probably diverged from other falcons towards the end of the Late Miocene
or in the Early Pliocene, about 85 million years ago (mya). As the
Peregrine-hierofalcon group includes both Old World and North American
species, it is likely that the lineage originated in western Eurasia or
Africa. Its relationship to other falcons is not clear; the issue is
complicated by widespread hybridization confounding mtDNA sequence
analyses; for example a genetic lineage of the Saker Falcon (F. cherrug)
is known[19] which originated from a male Saker producing fertile young
with a female Peregrine ancestor some 100,000 years ago.[ref]
Today, Peregrines are regularly hybridized in captivity with other
species such as the Lanner Falcon (F. biarmicus) to produce the "perilanner",
a somewhat popular bird in falconry as it combines the Peregrine's
hunting skill with the Lanner's hardiness, or the Gyrfalcon to produce
large, strikingly colored birds for the use of falconers. As can be
seen, the Peregrine is still genetically close to the hierofalcons,
though their lineages diverged in the Late Pliocene (maybe some 2.52
mya in the Gelasian).
Ecology and behavior
The Peregrine Falcon lives mostly along mountain ranges, river
valleys, coastlines, and increasingly in cities.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 climes typically migrate great distances during the
northern winter.The Peregrine Falcon is often stated to be the fastest
animal on the planet in its hunting dive, the stoop, which involves
soaring to a great height and then diving steeply at speeds commonly
said to be over 320 km/h (199 mph), and hitting one wing of its prey so
as not to harm itself on impact.A study testing the flight physics of an
'ideal falcon' found a theoretical speed limit at 400 km/h (250 mph) for
low altitude flight and 625 km/h (390 mph) for high altitude flight.[43]
In 2005, Ken Franklin recorded a falcon stooping at a top speed of 389
km/h (242 mph).
The life span in the wild is up to 15.5 years.[6] Mortality in the
first year is between 5970%, declining to between 2532% in adults.[6]
Apart from anthropogenic threats like collision with human-made objects,
the Peregrine may be killed by large eagles or large owls. The Peregrine
Falcon is host to a range of parasites and pathogens. It is a vector for
Avipoxvirus, Newcastle disease virus, Falconid herpesvirus 1 (and
possibly other Herpesviridae), and some mycoses and bacterial
infections. Endoparasites include Plasmodium relictum (usually not
causing malaria in the Peregrine Falcon), Strigeidae trematodes,
Serratospiculum amaculata (nematode), and tapeworms. Known Peregrine
Falcon ectoparasites are chewing lice[45] Ceratophyllus garei (a flea),
and Hippoboscidae flies (Icosta nigra, Ornithoctona erythrocephala).
Feeding
The Peregrine Falcon feeds almost exclusively on medium sized birds
such as doves, waterfowl, songbirds, waders and pigeons.Worldwide, it is
estimated that between 1,500 and 2,000 bird species (up to roughly a
fifth of the world's bird species) are predated by these falcons. In
North America, prey has varied in size from 3-g hummingbirds to a 3.1-kg
Sandhill Crane (killed by a peregrine in a swoop).Other than bats taken
at night, it rarely hunts small mammals, but will on occasion take rats,
voles, hares, mice and squirrels; the coastal populations of the large
subspecies pealei feed almost exclusively on seabirds. In the Brazilian
mangrove swamp of Cubatγo, a wintering falcon of the subspecies tundrius
was observed while successfully hunting a juvenile Scarlet Ibis. Insects
and reptiles make up a small proportion of the diet, which varies
greatly depending on what prey is available. In urban areas, the main
item of the Peregrine's diet is the Rock or Feral Pigeon, which comprise
80% or more of the dietary intake for peregrines in some cities. Other
common city birds are also taken regularly, such as Mourning Doves,
Common Swifts, Northern Flickers, Common Starlings, American Robins and
various corvids. The Peregrine Falcon hunts at dawn and dusk, when prey
are most active, but in cities also nocturnally, 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. It requires
open space in order to hunt, and therefore often hunts over open water,
marshes, valleys, fields and tundra. It searches for prey either from a
high perch or from the air. Once prey is spotted, it begins its stoop,
folding back the tail and wings, with feet tucked. The air
pressure from a 200 mph (320 km/h) dive could possibly damage a bird's
lungs, but small bony tubercles in a falcon's nostrils guide the shock
waves of the air entering the nostrils (compare intake ramps and inlet
cones of jet engines), enabling the bird to breathe more easily while
diving by reducing the change in air pressure. To protect their eyes,
the falcons use their nictitating membranes (third eyelids) to spread
tears and clear debris from their eyes while maintaining vision. Prey is
struck and captured in mid-air; the Peregrine Falcon strikes its prey
with a clenched foot, stunning or killing it, then turns to catch it in
mid-air.[50] The Peregrine will drop it to the ground and eat it there
if it is too heavy to carry. Prey is plucked before consumption.
Reproduction
The Peregrine Falcon is sexually mature at the end of the first year
of age but in healthy populations they breed after two to three years of
age. The 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. 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. The Peregrine
Falcon is territorial during the breeding season; nesting pairs are
usually more than 1 km (0.6 miles) apart, and often much farther, even
in areas with large numbers of pairs. 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 to seven in a 16 year period. The pair
defends the chosen nest site against other Peregrines, and often against
ravens, herons, gulls and (in ground nest) mammals like foxes,
wolverines, felids, bears and wolves. Both nests and (less frequently)
adults are predated by larger-bodied raptorial birds like eagles, large
owls, or Gyrfalcons. Peregrines defending their nests have managed to
kill raptors as large as Golden Eagles and Bald Eagles (which they
normally avoid) that have come close to the nest.
The Peregrine Falcon nests in a scrape, normally on cliff edges or,
today regularly in many parts of its range, on tall buildings or
bridges. Cliff nests are generally located under an overhang, on ledges
with vegetation, and south-facing sites are favored. 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, there was a large population of peregrines in
central and western Europe using the disused nests of other large birds.
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.[10] In remote, undisturbed areas such as
the Arctic, steep slopes and even low rocks and mounds may be used as
nest sites. The human-made structures used for breeding closely resemble
the natural cliff ledges that the Peregrine prefers for its nesting
locations.
Peregrine Falcon chick
Mostly three to four eggs (range 1-5) are laid in the scrape. The
eggs are white to buff with red or brown markings. They are incubated
for 29 to 33 days, mainly by the female. The male also helps with the
incubation of the eggs over day, but at night only the female incubates.
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 (the Australian subspecies macropus
may breed as late as November and equatorial populations may nest
anytime between June and December). The female generally lays another
clutch if the eggs are lost early in the nesting season, though this is
extremely rare in the Arctic owing to the short summer season. As a
result of some infertile eggs and natural losses of nestlings, the
average number of young found in nests is 2.5, and the average number
that fledges is about 1.5.
After hatching, the eyases, or chicks, are covered with creamy-white
down and have disproportionately large feet. The male, which is called
the "tiercel", brings food to the female and chicks, but the chicks are
fed by the female, which stays at the nest and watches the young. The
hunting territory of the parents can extend a radius of 19 to 24 km
(12-15 miles) from the nest site.[56] Chicks fledge 42 to 46 days after
hatching, and remain dependent on their parents for up to two months.
Peregrine Falcon chick in basket on telecommunication tower after
ringing, area Sauerland, Germany
Pesticides
The Peregrine Falcon became an endangered species because of the use
of pesticides, especially DDT during the 1950s, 60s, and 70s. Pesticide
biomagnification caused organochlorine to build up in the falcons' fat
tissues, reducing the amount of calcium in their eggshells. With thinner
shells, fewer falcon eggs survived to hatching. In several parts of the
world, such as the eastern USA and Belgium, this species became extinct
as a result.
Illegal collectors
Peregrine eggs and chicks are often targeted by black marketeers and
unscrupulous egg collectors, so it is normal practice not to publicize
unprotected nest locations.
Falconry
The Peregrine Falcon was used in falconry for more than 3,000 years,
beginning with nomads in central Asia.[52] Due to its ability to dive at
high speeds, it was highly sought-after and generally used by
experienced falconers.[11] Peregrine Falcons are also occasionally used
to scare away birds at airports to reduce the risk of bird-plane
strikes, improving air-traffic safety, and were used to intercept homing
pigeons during World War II.
Recovery efforts
In the USA, Canada, Germany and Poland, Wildlife services in
Peregrine Falcon recovery teams breed the species in captivity. The
chicks are usually fed through a chute or with a hand puppet mimicking a
Peregrine's head, so they cannot see to imprint on the human
trainers.Then, when they are old enough, the rearing box is opened,
allowing the bird to train its wings. As the fledgling gets stronger,
feeding is reduced forcing the bird to learn to hunt. This procedure is
called hacking back to the wild. To release a captive-bred falcon, the
bird is placed in a special cage at the top of a tower or cliff ledge
for some days or so, allowing it to acclimate itself to its future
environment. Worldwide recovery efforts have been remarkably successful.
The widespread restriction of DDT use eventually allowed released birds
to breed successfully. The Peregrine Falcon was removed from the U.S.
Endangered Species list on August 25, 1999. The population studies and
recovery plan devised by Dr. Richard M. Bond and William Griffee are
considered by the Cooper Ornithological Society and the Pergrine Fund to
have been critical to the recovery effort for the Peregrine Falcon
population in the United States.
Current status
In the USA
Many Peregrine Falcons have settled in large cities, nesting on
cathedrals, skyscraper window ledges, and the towers of suspension
bridges. As early as 1946, Peregrine Falcons were nesting atop
Philadelphia City Hall, which is believed to be among the first
artificial structures in the world to be used as a nest site by this
species.[67] In Virginia, state officials working with students from the
Center for Conservation Biology of the College of William and Mary in
Williamsburg successfully established nesting boxes high atop the George
P. Coleman Memorial Bridge on the York River, the Benjamin Harrison
Memorial Bridge and Varina-Enon Bridge on the James River, and at other
similar locations. Thirteen new chicks were hatched in this Virginia
program during a recent year. Over 250 falcons have been released
through the Virginia program.[68] The New York State Department of
Environmental Conservation reported that there were 67 pairs of
peregrine falcons in the state during 2008.
In Britain
In Britain, there has been a recovery of populations since the crash
of the 1960s. This has been greatly assisted by conservation and
protection work led by the Royal Society for the Protection of Birds.
Peregrines now breed in many mountainous and coastal areas, especially
in the west and north, and nest in some urban areas, capitalizing on the
urban pigeon populations for food.
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