The Peregrine Falcon is one of the most remarkable birds of prey in North America, or maybe even the world. It feeds mostly off of birds it catches in the air, taking advantage of its awesome diving ability. They have one of the fastest diving speeds in the world, reaching 220 miles per hour.
The falcon, or female Peregrine, is about 1/3 bigger than the tiercel, or male falcon. A Peregrine Falcon is a large falcon, with a wingspan of about 3' 4" and a length of 1' 1" to 1' 9". A male Peregrine weighs about 1.3 lbs while a female weighs 1.8 lbs. Notes- Reverse Sexual Dimorphism
The Peregrines have a dark blue back and tail that is faintly barred; the head is dark on top with dark stripes that run down the face. Their wings are typical of a falcon, long and pointed, barred dark blue on the undersides. The legs and feet are bright yellow, while the underside is light colored with vertical stripes across the breast, stomach and legs. The Peregrine Falcon is an example of Gloger's Rule and many theories about color phases. Immature Peregrine Falcons are mostly brown with a lighter colored underneath with dark brown stripes. Notes- Color Phases
Peregrine Falcons are found everywhere in the world except for Antarctica, which causes them to have several variations and sub-species (one estimate is 22). Found on the Arctic tundra and throughout Europe, Africa, North America, South America, the Pacific Islands, and Australia. 3 subspecies of the Peregrine Falcon exist in North America- the American, the Arctic, and Peale's.
The Peregrine Falcon can kill a bird on impact; a notch on their beak aids them in quickly snapping the spine of its prey. Prefers open terrain in order to obtain good dives, usually found on high cliffs on rivers and coasts. Also found in the city on high buildings, some Peregrine Falcons have actually become migratory, depending on whether or not their prey migrates.
Nests are usually depressions on the bare rocks of cliffs; there have also been reports of Peregrines nesting in trees in the Eastern U.S., as well as on skyscrapers and bridges. Peregrine Falcons prefer sheer cliffs of 150 feet or more elevation. They will also take over abandon eagle, hawk, and raven nests. They are territorial, defending the land around the eyrie (nest) aggresively within a 110 yard radius (they may abandon a nest, however, if they are harassed constantly). Home ranges are usually about 32.3 square miles in area, and nesting spots are 3 miles apart, at a minimum.
Peregrine Falcons are mostly monogamous, and often remain with their breeding partner throughout the non-breeding season. Breeding territories are established by males in March, usually near a lake, river or marsh, and try to attract females by doing aerial acrobatic displays. 2-4 slightly red, rust blotched eggs are laid in May at intervals of about 2-3 days between eggs. Both parents incubate the eggs, but the female does most of the incubation. The eggs hatch in 28-34 days, and fledging occurs about a week afterward. By August the young are learning flight maneuvers and how to catch pray in midair. The Peregrines may reach maturity in 2 years, but breeding does not usually occur until they are 3 years old.
Peregrines may catch their food in midair using their stupendous diving power to catch their prey, or by sitting on a perch and attacking the prey as it flies by (also known as still-hunting). Hunting occurs in early morning or late afternoon. Juveniles usually take to the skies earlier than the adults. Peregrines usually dine on rock doves, mourning doves, crested and least auklets, songbirds, waterfowl, and other small birds. They will occaisionally attack small mammals. Females, with their larger size, usually take on larger prey than the males, but the pairs often hunt together. The Peregrine Falcon is listed as "endangered" in the United States (from pesticides and other poisons), but are being bred in captivity in the U.S. By 1994, 283 young peregrine falcons were released in 16 different sites in Idaho alone. 14 pairs were reported to be nesting in the state and hatched 112 young since 1988. Also common in falconry.