The Peregrine falcon, Falco peregrinus, is a bird of prey (or raptor) which has captured the attention and imagination of ornithologists and bird-watchers alike for several thousand years. With a body length of 15-20 inches and a body weight of 1.25-3.75 lbs, the falcon is built specifically for traveling at high speeds (up to 180 mph) in order to catch its prey. The name Falco peregrinus is derived from the Latin falx, or sickle-shaped, and peregrinus, meaning wandering. It is unclear whether the former is derived from the shape of the bird's silhouette in the sky or from the shape of its beak, but the latter name comes undoubtedly from its propensity to migrate great distances. The Peregrine belongs to a genus made up of 37 species.
Predation
Two sequences of pictures from Race Rocks above have been taken by Pam Birley showing the peregrine eating a shorebird.and a sea gull. Though peregrine falcons, like other birds of prey, are considered to be near the top of the food web, they are not completely free from predators. Great horned owls and golden eagles have been known to attack them. Humans have also been known to take their eggs in hopes to raise the falcons for hunting purposes.
As top predators, peregrine falcons play an important ecosystem role in regulating the populations of their prey.
Habitat
Peregrine Falcons prefer open habitats such as grasslands, tundra, and meadows. They nest on cliff faces and crevices. They have recently begun to colonize urban areas because tall buildings are suitable for nesting in this species, and because of the abundance of pigeons as prey items.
Peregrine falcons prey almost exclusively on birds, including mourning doves, pigeons, shorebirds,(see slide shows above) waterfowl, and smaller songbirds. They will also eat small reptiles and mammals. Although peregrine falcons capture their prey with their claws, they generally kill prey with their beak.
Conservation Status
Peregrine falcons have suffered due to their dangerous position atop the food chain. Pesticides accumulate in small (not lethal) quantities in the tissues of small birds and mammals, but become concentrated enough in predatory birds, such as falcons, to kill them or render them incapable of producing offspring. Organochlorine pesticides (DDT and dieldrin) have been proven to reduce the birds' ability to produce eggshells with sufficient calcium content, making the egg shells thin and more likely to break. Peregrine falcon populations dropped greatly in the middle of the 20th century, they were threatened worldwide by the increasing use of pesticides. All breeding pairs vanished in the Eastern United States. A successful captive breeding/reintroduction program, combined with restrictions in pesticide use, has been the basis of an amazing recovery by peregrine falcons. Now the use of many of the chemicals most harmful to these birds is restricted. It is not yet restricted in the areas of Central and South American where many subspecies spend the winter. After having been on the endangered list since 1969, the incredible recovery of Peregrine Falcons has become a perfect example of how effective human conservation can be. In the 1990's they were taken off the lists of endangered species in the United States.