Peregrine Falcon
(Falco peregrinus)
Habitat
Peregrines typically require mountain crags and cliffs for nesting. Often these
overlook river valleys or marine habitats. They prefer long cliffs with several
ledges where access is difficult for man and other potential sources of disturbance.
Open areas are required for hunting avian prey. Peregrines are found in most
major North American cities, as skyscrapers mimic their preferred cliff habitats.
Physical
Characteristics
Peregrines are sleek-bodied, crow-sized raptors with long pointed wings. Weights
range from 1-2.5 pounds (.45-1.13 kg) with females considerably larger than males.
There is racial variation with Peale’s being the largest and darkest and
the tundra race the smallest. Peregrines appear hooded. Adults have grayish backs
with a light upper breast and dark barring on the lower breast. Juveniles are
browner and heavily streaked below. Sexes are similar in plumage. The bare skin
of the feet, cere and eye ring is yellow in adults and light blue in the young
birds.
Life
Span
Usually less than 20 years in captivity, rarely that long in the wild.
Diet
In the wild: They feed almost exclusively on birds
which are taken in midair while making spectacular vertical dives called
stoops. Shorebirds are a favorite, although urban peregrines feast
on pigeons. Rarely mammals are taken, and young birds will go after
large flying insects.
At
the zoo: Coturnix quail.
Reproduction
Peregrines form long-term pair bonds and are highly protective of their
nesting territory, which they use year after year. They produce
one clutch per year, but will occasionally re-lay if the nest fails
early in the cycle. Three to five reddish blotched cream colored
eggs are laid in a scrape or depression on a cliff ledge. Although
the female does most of the incubation, both parents take part
for an average of 33-35 days. Many peregrines use platform nestboxes
that have been provided on buildings and other man-made structures.
Rarely, abandoned tree nests of other birds are used.
Life Cycle
The female does the majority of brooding of the nestlings.
The young become mobile in the nest at 28 days, and usually fledge
within 40 days. After the youngsters leave the nest, they continue
to receive parental care, as they are taught how to catch their own
food. This continues for at least two months, and in migratory populations,
sometimes will continue after the family departs southward. Some peregrines
will remain in their nesting territory year-round, although northern
populations migrate south. Tundra peregrines may travel from the arctic
to South America and back each year.
The Fastest Moving
Animal
Peregrines are the best known of all the falcons due to their wide range as
well as their extraordinarily spectacular stooping ability. Incredible speed,
maneuverability and strength combine to make them the embodiment of the ultimate
avian predator. Peregrines will identify prey from distances up to one mile
away. After choosing a potential victim, they will occasionally take it by
direct attack, or more commonly, rise high above and dive or stoop at the bird
that they wish to kill. Many people have been skeptical at the estimated speeds
for these spectacular stoops. In recent years radar guns have been used to
measure the speed of a diving bird at well in excess of 200 mph (320 kph)!
Their quarry is almost always a bird and it is captured in midair. A notch
on the upper beak known as the tomial tooth is used by all falcons, including
peregrines, to severe the spinal column of injured victims. Peregrines sometimes
consume smaller prey species in flight after dispatching them, particularly
during migration.
Location
at the Zoo
A peregrine
falcon can be seen at the zoo’s Raptor Center. Other birds of prey
that can be viewed at the Raptor Center include the bald eagle, Harris’s
hawk, gyrfalcon, turkey vulture as well as spectacled and barred
owls.
Conservation
Connection
Peregrine falcons
were listed as endangered under the Endangered Species Act of 1973.
Although never that abundant as breeding birds in the continental
United States, the population went into a nose-dive beginning in
the late 1940s. By the mid-1960s nesting populations had been eliminated
east of the Mississippi River. Western populations were reduced by
up to 90%. Scientists investigating the decline found very high concentrations
of the pesticide DDT and its by-products in their tissues. Because
they fed on birds, many of which ate insects, peregrines received
a mega-dose due to bioaccumulation of DDT and its residues up the
food chain. The chemicals interfered with calcium deposition on their
eggs, which failed to hatch. Illegal shooting, collisions with man-made
objects, and egg and chick collection also impacted populations,
but none of these compared with the drastic effects of pesticides.
DDT was banned for usage in North America in 1972, and coupled with
protection under the ESA and captive reintroduction efforts, these
magnificent birds began to recover. In 1984, the tundra subspecies
was downgraded to threatened status, and by the mid-1990s populations
of American peregrine falcons began to approach the recovery goals
that were set when they were listed. They were delisted in August
1999. They may even exceed historical levels here in the Northwest,
as human related changes have resulted in more open space, which
provides suitable foraging habitat for these falcons. The peregrine
falcon continues to be listed on Appendix 1 by CITIES.
Humans need raptors. Here are only a few of the benefits raptors provide:
- Raptors help keep
animal populations in balance.
- Raptors consume
many animals that humans consider as pests, including mice, rats
and destructive species of insects. This helps to control disease
and damage to crops.
- As top predators
of their food chain, raptors are an indicator species of the overall
health of the ecosystem in which they live.
- Of equal importance,
witnessing wild raptors enriches each of our lives. Imagine what
life would be like if we could no longer gaze upon the grandeur
of raptors soaring high above.
How You Can
Help!
Efforts to save threatened and endangered raptors require cooperation and support
at international, national, regional and individual levels. You can help in
this cause. Join and become active in Woodland Park Zoo and other conservation
organizations of your choice. Recycle forest products. Eliminate or reduce
pesticide use. Let your elected representatives know your views about the conservation
of migratory birds and their wild habitats.
Contact Woodland Park Zoo at webkeeper@zoo.org to find ways you
can support conservation programs at the zoo. Discover more about raptors by
contacting the Peregrine Fund at their Web site www.peregrinefund.org. Learn other ways
you can help conserve wildlife and their habitats by visiting our How You Can Help page.
Sources and
Suggested Reading
Johnsgard, Paul A. 1990. Hawks, Eagles, and Falcons of North America.
Smithsonian Institution, Washington, DC. 403 p.
For Kids!
Burnie, David. 1988. Bird (Eyewitness Books). Alfred
A. Knopf, Inc., New York, NY. 64 p.
Zoobooks. 1986. Birds of Prey. Wildlife Education, Ltd., San Diego,
CA. 16 p.