Classification and Range
Peregrines are in the family Falconidae that includes the falcons and caracaras. The genus Falco has 38 species of falcons. Peregrines are distributed worldwide but nest mostly in arctic and temperate regions. Three North American subspecies are recognized. The tundra race (tundrius) is highly migratory and found from coast to coast. The Peale's peregrine (pealei) nests from coastal Alaska down the coast to Washington. Continental peregrines (anatum) were extirpated from eastern North America before 1970, but after reintroduction efforts, they are once again found across the continent.
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.
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.
LUsually less than 20 years in captivity, rarely that long in the wild.
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.
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.
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.
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. Recycle forest products. Eliminate or reduce pesticide use. Support breeding programs for endangered birds of prey at zoos and other animal care organizations. Let your elected representatives know your views about the conservation of migratory birds and their wild habitats.
Contact Woodland Park Zoo at firstname.lastname@example.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.
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.