The peregrine falcon (Falco peregrinus) is a majestic bird of prey, with slate blue upper parts and cream-coloured under parts. It's underparts are distinguished by horizontal black barring and spotting. The peregrine's elegant head pattern makes this species very distinctive, even from a distance. Male peregrines weigh an average of 611 grams and females 952 grams. The peregrine falcon once bred throughout Canada, however its range has become much more restricted in recent years as populations have undergone declines. North American peregrines from areas in the northern United States, southwestern British Columbia, and southern Ontario winter in such places as -- the coast of the Gulf of Mexico, Latin America & South America.
There are three subspecies of the peregrine falcon in Canada. The Arctic peregrine falcon (Falco Peregrinus tundrius) occurs across the wide arc of tundra from the Mackenzie Delta to Hudson Bay and Ungava, and north to Baffin Island. This subspecies is listed as vulnerable. The Pealie peregrine falcon (F. p. pealei) is non-migratory, and inhabits the Queen Charlotte Islands and Moore Island, British Columbia. The Pealei peregrine is listed as vulnerable within Canada. Most of the southern Canadian breeding populations are of the anatum subspecies (F.p. anatum), which is a Canadian endangered species.
Peregrines are powerful, streamlined birds, capable of soaring to heights of 600m and are among the world's swiftest birds, flying at speeds of more than 200km/h. Peregrine falcons are expert hunters feeding on songbirds, shore birds, waterfowl, sea birds and pigeons, all of which are caught in flight. The peregrine is anatomically specialized for hunting by direct pursuit in open areas. The prey often tries to escape by gaining altitude but the peregrine uses its speed to stay above the prey, and then dives, killing the prey by a direct blow of the closed fist.
In addition to speed the peregrine may use the element of surprise -- swooping from the direction of the sun or suddenly appearing from behind a cliff, or around the corner of one of our sky scrapers.
Pairs are sometimes cooperative when hunting during the breeding season. Peregrines, and particularly the Arctic peregrines, occasionally prey on small mammals such as lemmings. On the wintering grounds, peregrines predominantly prey on migratory shore birds.
In the breeding season, falcons nest on a cliff ledge, cliff top, a ledge or top of the tallest building is also preferred, preying on pigeons in nearby parks. Occasionally peregrines may nest on the ground. Females lay two to five eggs in the "scrape" or nesting site, which is usually just a shallow depression. Eggs are incubated for 32 days, mainly by the female, while the male hunts for food. Young are able to fly at about 35-40 days after hatching, but remain dependent on the adults for several weeks after they leave the nest. Young may stay together for a short time after they become independent of the adults. Peregrines rarely breed before three years of age. The average life span is four to five years but individuals have been known to live much longer.
The anatum subspecies is the race of Peregrine Falcon breeding in Alberta. According to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) , the anatum subspecies is currently considered to be endangered in Canada. An endangered species is any indigenous species of fauna or flora that is threatened with imminent extirpation or extinction throughout all or a significant portion of its Canadian range
Birds - Waterfowl, Pigeons, Doves, shore birds, Songbirds
Tundra, Savannah, Seacoasts, Mountains, Cities with high buildings
Ledges on cliffs, ledges on high buildings in cities (including Regina City Hall)
Disturbance of cliff nesting sites, shooting, egg collecting, and the taking of young for falconry have reduced peregrine falcon populations. However the largest present day threat to the peregrine is pesticides. Peregrines are predators at the top of the food chain, and accumulate high levels from their prey, since pesticide residue becomes more and more concentrated as it works its way up the food chain. This phenomenon is known as bio accumulation.
DDT, an organochlorine compound used as a crop pesticide, was banned throughout North America in the last decade. Organochlorines are not only toxic but highly persistent in living tissues, resisting breakdown and resulting in accumulation, particularly in long-lived predator species such as the peregrine falcon. DDE, the major breakdown compound of DDT, is still found in the tissues and eggs of peregrine falcons. These pesticide residues result in females laying very thin-shelled eggs which cannot sustain the weight of incubation, thus causing reproductive failure.
While many South and Central American countries have banned the use of DDT, its use still persists in parts of Latin America, the wintering grounds of many peregrine populations. This use alone, causes major problems for the peregrine. Blood samples taken from southern U.S. populations of peregrines during fall and spring migration showed that most of the pesticide burden was accumulated in wintering areas in Latin America. Young birds accumulated levels of DDE as high as those in adult birds after just one winter in the south.
The ban on DDT in North America came too late to rescue the anatum subspecies, and they were virtually extirpated from much of southeastern Canada and the prairie provinces in the 1970s. Fortunately, a number of falcons had been taken into captivity as stock for a captive breeding program in the hopes of re-establishing peregrines in areas where they had disappeared. The anatum is listed as endangered, however there are some still surviving in the wild. The sub-species tundrius, was down listed to vulnerable in 1972.For more information, check out these references:
Radar observations of the stoop of the Peregrine Falcon Falco peregrinus and the Goshawk Accipiter gentilis
Article in: Ibis; vol. 129 (1987); pp. 267-273
Baker, J. A.
1967, London; New York
Brown, Leslie /Amadon, Dean
Eagles, Hawks and Falcons of the World I-II
1968, New York (McGraw-Hill)
Brown, L. H.
Birds of Prey: their Biology and Ecology
(No Publishing Information)
Dunne, Pete / Sibley, David / Sutton, Clay
Hawks in flight
Grossman,Mary L. / Hamlet,John
Birds of Prey of the world
1960, New York (Potter)
Flight strategies of migrating hawks
1989 (University of Chicago Press)
How Birds Migrate
Publ.: Stackpole Books
A Colour Atlas of Avian Anatomy
1990, New York (Wolfe Publishing)
Understanding Gliding: the principles of soaring flight
1977 (A. & C. Black)
The Peregrine Falcon
Publ.: T. & A. D. Poyser
Year and place: 1980 London
Squires, John R. / Ruggiero, Leonard F.
Winter movements of adult northern goshawks that nested in Southcentral Wyoming
Letter in: Journal of Raptor Research; vol. 29 (1995); iss. 1; pp. 5-9
Northern goshawk calling tapes
20 min. Alarm call and wailing call.
Tucker, Vance A. / Parrott, C. G.
Aerodynamics of gliding flight in a falcon and other birds
Article in: Journal of experimental Biology; vol. 52 (1970); pp. 345-367
Tucker, Vance A.
Gliding birds: the effect of variable wing span
Article in: Journal of experimental Biology; vol. 133 (1988); pp. 33-58