Peregrine Falcon
Falco peregrinus
(Wandering falcon)
Prepared by John Winebrenner

Subspecies:

Nineteen recognized; Three in North America: tundrius, anatum, pealei

Distribution:

Worldwide (except Antarctica). In North America, the tundrius subspecies is found from Alaska to Greenland. The subspecies anatum is found south of the tundra to northern Mexico. The pealei peregrine is found in Washington to Western Alaska across the Aleutians to the Russian coast. At least one of three subspecies may be found in some part of North America at anytime of the year.

Description:

• Length: Male 14-16" Female 16-18"
• Wingspan: Male 37-39" Female 40-46"
• Weight: 550 to 1500 g

Peregrine falcons are large dark falcons with thick dark "mustache marks." Adult birds are slate to blue-gray on the upperparts. The gray and black banded tail has a wide white terminal band. The underparts are creamy white. The upper breast normally remains unmarked, while the belly and undertail coverts are barred with black. The underwings are also barred with black and appear fairly dark when seen from below. The cere, eye ring, legs, and feet are bright yellow. This is the only North American falcon whose wingtips extend to, or almost to, the tail tips on perched birds. As with most birds of prey, sexes are similar in appearance, and the female is noticeably larger than the male.

Immature birds are light brown to chocolate above. The underparts are creamy buff with heavy dark streaking. The dark brown tail has creamy, usually incomplete, bands and a wide white terminal band. The cere and eye ring are light blue, occasionally yellowish. The legs and feet vary from light blue to yellowish.

The three North American subspecies are distinctive. The Tundra form is the smallest of the three and the lightest in color, while the Peale's form is the largest and darkest. The anatum form is medium in both size and color.

Habitat:

Open habitats from tundra, savanna, tropics, hot deserts and sea coasts up to 12,000 feet, especially, along rivers and lakes. Also occurs in open forests. In recent years, peregrines have started inhabiting large cities, perching on tall buildings in place of cliff ledges.

Feeding:

Prey consists almost entirely of medium sized birds. Typical prey items include pigeons, starlings, nighthawks, and assorted shorebirds. More than 300 species of birds have been identified as prey in North America. Occasionally, bats, rats, rabbits and voles are also taken.

The peregrine is one of the fastest birds in the world, exceeding 60 mph in level flight and as fast as 175 mph in a dive or "stoop". There have been some unconfirmed reports of dives that exceeded 200 mph. Peregrines can easily overtake most birds in level flight. After soaring at very high altitudes, the peregrine will stoop towards the prey in an almost vertical dive. Thus, the prey is taken by surprise and has little chance for escape. Another effective hunting strategy is dropping down on prey from a high perch.

Movements:

Migration is mainly along the coasts and the Great Lakes. The tundra birds move as far south as Central Argentina and Chile during the boreal winter. Some even spend the winter in the Amazon basin at Manaus, Brazil. In the first year, dispersal is greatest with females ranging further than males. Adult males tend to have greater site fidelity than females. Pairs often remain together.

Breeding:

First breeding occurs at two years of age. The nest is little more than a small round scrape in the accumulated debris on a ledge of a cliff or a tall building. Old stick nests of other raptors are also used, as well as the hollows of broken trees. These are usually 50 to 200 feet above the ground. Both parents incubate the 3-4 creamy or buff eggs, with red and brown markings, for 28 to 29 days. The young are able to fly 35 to 42 days after hatching. During nesting, the male does most of the hunting while the female broods and feeds the chicks.

Status:

In the 1960s, peregrine falcons were nearly extirpated from the eastern half of North America due to the heavy use of DDT and other pesticides. With the banning of these harmful chemicals, and aggressive reintroduction programs, the number of peregrines has increased dramatically and the North American population is now stable. Previously on the Endangered Species list, the peregrine in North America has now been upgraded to Threatened status. Other than North America, the peregrine is not globally threatened.