What
do peregrine falcons look like?
The peregrine
falcon belongs to the genus "Falco," which is characterized
by long pointed wings. In fact the word Falco is derived from "falx,"
the Latin word for sickle, in reference to the distinct sickle-shaped
silhouette of the peregrine falcon’s extended wings in flight.
Also unique to this species is the notched beak that is used to
kill prey by severing the spinal column at the neck. The peregrine
falcon is a crow-sized bird, weighing just over two pounds with
a wing span of approximately 3 feet. An adult peregrine has a dark
grey back and crown, dark bars or streaks on a pale chest and abdomen,
and heavy malar (cheek) stripes on the side of the face. Immature
peregrines are buff colored in front and have dark brown backs;
adults are white or buff in front and bluish-gray on their backs.
Females and males are identical in appearance, however, the female
can be a third larger than the male.
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Where
is the peregrine falcon found?
The peregrine
falcon has the most extensive natural distribution of any bird in
the world, limited only by high elevations, extreme heat, and extreme
cold. It is found on all continents except Antarctica. In most parts
of the world, it is absent only in the high mountains, in large
tracts of desert or jungle, and on isolated islands in the oceans.
The American peregrine falcon breeds in Mexico, the United States,
and Canada.
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How
did the peregrine falcon get its name?
Peregrine in
Latin is "Peregrinus," which means traveler. Peregrine
falcons are well known for their long fall and spring migratory
flights to and from their nesting and wintering habitats. The Arctic
peregrine falcon lives up to its name, breeding on the north slope
of Alaska east across northern Canada to Greenland in summer and
migrating as far south as the tip of South America to winter.
The sport of
falconry involves training falcons to hunt game, and people who
practice the sport are called falconers. Early falconers referred
to peregrine falcons as such because - unlike most birds use for
the sport of falconry - they were always trapped during migration,
and not taken from the nest.
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How
fast can a peregrine falcon fly?
In level flight,
the normal speed for peregrines is about 40 to 55 miles per hour.
In a stoop (dive) peregrine falcons can attain speeds in excess
of 200 miles per hour as they attack their prey.
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How
do they capture their prey?
Peregrine falcons
are aerial predators, feeding on live birds and an occasional bat,
which they capture in mid-air. Peregrine falcons often hunt in tandem,
alternately diving on their prey until it is caught.
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Do
peregrine falcons have natural predators?
Peregrine falcons
are fast, aggressive, and fearless predators located at the top
of their food-chain; they rarely suffer from predation by other
animals. Great-horned owls and golden eagles are known to occasionally
kill fledgling peregrines, and less often, adults. Peregrine eggs
sometimes fall victim to raccoons and red-tailed hawks. The nestlings
of ground-nesting Arctic peregrine falcons may be preyed upon by
grizzly bears and foxes.
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Do
peregrine falcons mate for life?
Yes, peregrine
falcons are monogamous. They also breed in the same territory or
area for their entire lives. There are exceptions, such as when
one mate dies or is replaced by a stronger individual. Sexual maturity
occurs during the second year of life, followed by approximately
one month of courtship. In the spring, 3 or 4 eggs are laid. Incubation
takes approximately 33 days and although both parents share incubating
duties, the female performs the greater share. Two or three chicks
usually hatch and fledge in approximately 42 days. After fledging,
young peregrine falcons are still dependent on their parents for
food until they learn to hunt, which takes about a month and a half.
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Do
peregrine falcons build nests?
Most birds
build nests made of sticks and soft natural fiber material in which
their eggs are incubated. Peregrine falcons lay their eggs in "scrapes,"
which are shallow indentations they scratch out with their talons
in the soft earth on the floor of their nests. Peregrine falcons
typically nest on ledges and in small shallow caves located high
on cliff walls. They have been known to use the abandoned nests
of other birds, and on the north slope of Alaska, commonly nest
on the ground.
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When
do American peregrine falcons breed?
American peregrine
falcons begin breeding activities in the south earlier than in northern
States. In Arizona and coastal California, peregrines begin nesting
in late February and early March. In Alaska, nesting begins in May.
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What
subspecies of peregrine falcon are native to North America?
There are three
subspecies nesting in North America:
- The Arctic
peregrine falcon (Falco peregrinus tundrius) nests on the north
slope of Alaska east across northern Canada to Greenland, and
winters in Latin America.
- The Peale’s
peregrine falcon (Falco peregrinus pealei) is a year-round resident
on the coasts of Washington, British Columbia, and Alaska north
to the Aleutian Islands.
- The American
peregrine falcon (Falco peregrinus anatum) nests in southern Alaska,
Canada, United States and northern Mexico.
Peregrine falcons
that nest in subarctic areas generally winter in South America,
while those that nest at lower latitudes exhibit variable migratory
behavior. Some are nonmigratory.
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What
was the historical size of the American peregrine falcon population?
The historical
status of the American peregrine falcon is not known, but it was
probably never common, even when compared to other birds of prey.
The limited historical data suggest a best estimate of 3,875 nesting
pairs. The decline of the American peregrine falcon population began
in the 1940s, was most pronounced during the 1950s and continued
through the 1960s into the early 1970s throughout most of its range.
By the time biologists realized the magnitude of the American peregrine
falcon decline, the population was only about 12 percent of what
it had been prior to the introduction of modern pesticides.
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What
caused the near extinction of the peregrine falcon in North America?
The use of
DDT as a pesticide during the 1940s, 1950s and 1960s resulted in
a precipitous decline of peregrine falcons in North America. During
this period of DDT use, eggshell thinning and nesting failures were
widespread in peregrine falcons, and in some areas, successful reproduction
virtually ceased. As a result, there was a slow but drastic decline
in the number of peregrine falcons in most areas of its range in
North America. DDE, a metabolite of DDT, prevents normal calcium
deposition during eggshell formation, resulting in thin-shelled
eggs that are susceptible to breakage during incubation. Peregrine
falcons feed near the top of the food chain and suffered from the
accumulation of DDE due to eating contaminated prey.
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How
many American peregrine falcons were there when the bird was first
placed on the endangered species list?
The eastern
population of the American peregrine falcon was gone and the populations
in the west had declined by as much as 90 percent below historical
levels. By 1975, there were only 324 known nesting pairs of American
peregrine falcons.
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How
many American peregrine falcons are there today?
There are between
2,000 and 3,000 breeding pairs of American peregrine falcons in
Canada, Mexico, and the United States.
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What's
the status of the peregrine falcon now?
Thanks to
the increase in peregrine falcon population, the U.S. Fish and Wildlife
Service was able to remove the species from the Federal list of
threatened and endangered species effective August 25, 1999. The
peregrine falcon will be monitored for several years to ensure that it no
longer needs the protection of the Endangered Species Act. If necessary,
the species can be added back to the list in the future. For more
on the recovery of the falcon and the species' monitoring plan,
visit the peregrine falcon recovery page.
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