Peregrine Falcon

SCIENTIFIC NAME

Falco peregrinus

CLASSIFICATION

Class:

Aves

Order:

Falconiformes

Family:

Falconidae

Genus:

Falco

Species:

peregrinus

SIZE

Length:

Male:

15-20 inches

Female:

18-21 inches

Weight:

Male:

550-660 grams

Female:

740-1120 grams

Wingspan:

Male:

37-39 inches

Female:

38-40 inches

APPEARANCE:

The body of the Peregrine Falcon is sleek and compact with long, pointed wings. They gain their adult plumage after their first annual molt at one year. The backs of Peregrines are slate gray in color. Their underparts are cream-colored with dark narrow barring on the flanks and belly from breast to tail-tip. The head is black which extends down below the eyes to cover the cheeks. The tail is slate gray with black bars and a white tip. The feet and legs are a bright yellow.

The plumage in adult Peregrines will vary. The arctic birds are the palest, and northwestern birds the darkest with the heaviest underneath pattern. The eye stripe in arctic birds is narrower. Plumage will also vary in the sub-species.

Immature Peregrines are much browner than the adults. Most of the feathers are edged in buff with brown markings on edges. Black streaks on cheeks are narrower than the adult’s, and the coverts are buffish-white. Underparts are buffed, streaked with brown. Underwing is barred with buffish-white to dark brown bars, and the undertail consists of narrow, widely spaced, wavy bars.

Like all falcons, the Peregrine Falcon has raptorial feet that are highly adapted to grasping their prey with the very long toes. They also have short beaks and jaw muscles modified to deliver powerful bites. Along with powerful jaws, the Peregrine has a Tomial Tooth, known as the “killing tooth.” It is a notch on the cutting edge of the upper beak that is used to sever the prey’s spinal column. The nostrils possess a prominent central bony tubercle.

RANGE/DISTRIBUTION:

Peregrine Falcons are found on every continent except Antarctica. They are located in most of North America, Asia, the southern tip of South America, Mid and Southern Africa, and are widespread in Europe and Australia. In North America they are most common from northern Alaska and northern Canada south to the Northwest and Mexico in the Rocky Mountains. They are now being re-introduced in the west and in New England.

HABITAT/TERRITORY SIZE:

The Peregrine Falcon prefers open landscapes such as rivers, flood plains, grasslands, meadows, and agricultural land. They tend to keep away from high mountains and dry desert regions. Some Peregrine Falcons have adapted well to cities where they nest on the ledges of buildings and have an abundant source of pigeons for prey.

MIGRATION:

Peregrines located furthest north in the arctic tundra migrate down to the tropical regions in winter. The rest are mostly year-round residents.

DIET:

The diet of Peregrine Falcons consists largely of birds ranging in size from finches to large ducks.

HUNTING METHOD:

Like other falcons, Peregrines will go into a fast dive after their prey, shape their long toes to look like a fist, and punch their prey. If the prey is not dead after this tremendous blow, they will use their “killing tooth” to sever the spinal cord.

Most birds of prey swoop, but none can attain the speed of the Peregrine Falcon. Peregrines have been reliably clocked at speeds of 200 m.p.h. in a dive. Because of these high speeds, their prey has very little chance when it is struck by such a force. This is why the Peregrine is one of the most efficient hunters.

BREEDING INFORMATION:

The male tends to arrive at the nesting territory ahead of the female and makes himself conspicuous by perching in prominent places, and by making loud calls and aerial acrobatics. Once a female arrives, she joins the male in his aerial acrobatics and the two may lock talons or touch beaks during the maneuvers. During the courtship, the male will feed the female. Courtship behaviors begin with the coming of spring.

The Peregrine’s nest usually consists of a shallow scrape in the soil of a rocky cliff to a low-lying bog. They will also nest in the abandoned nests of other birds. Man-made nesting platforms are also used, as are ledges of tall office buildings. Females lay 2-6 that are creamy buff with red and red-brown markings. The incubation period lasts between 28-29 days, and the young are able to begin flying at 35-42 days.

STATUS:

Man is the worst enemy although scavenger birds do wipe out a number of eggs. Because of the use of DDT, the Peregrine was almost erased from existence in the 1960’s. The chemical thinned the egg shells so they were easily crushed while being incubated. DDT was banned in the 1970’s and, with the help of captive breeding programs, the Peregrines are now making a comeback and were removed from the Endangered Species List in 1999.

BIBLIOGRAPHY:

“Eagles, Hawks, and Falcons of the World,” by Brown, Leslie, and Dean.
Vol. 2. New York: McGraw-Hill Book Company, 1968.
“The Falcons of the World,” Cade, Tom. New York: Cornell University Press, 1982.
“Birds of Prey,” Cuisin, Michel. New Jersey: Silver Burnett Company, 1980.
Nongame Wildlife Leaflet: “Idaho’s Birds of Prey.”
“Snake River Birds of Prey Pamphlet” by the Bureau of Land Management.