Prefer open areas like wetlands, tundra, savanna, seacoasts and mountain meadows, but will also hunt over open forest; hunting territories extend up to 27 km (17 miles) from the nest.
Peregrine Falcons have the broadest natural distribution of any bird in the world, and are found on every continent except Antarctica; anatum is the most widespread of the three subspecies in Canada.
Mostly birds such as pigeons, medium to large songbirds, shorebirds, and occasionally larger birds like ducks. They may also eat small mammals, reptiles and even insects.
Peregrines catch their prey on the fly, killing it on impact or using their uniquely notched beaks to sever the spinal column. They often hunt in tandem, alternately diving at their prey until they catch it.
Peregrines become sexually mature at one year of age. They keep the same mate and territory for life, unless one of them dies or is chased off by a stronger individual.
Peregrines typically nest on cliff ledges, but will also nest on tall structures such as office towers, smokestacks and high bridges. They lay their eggs in “scrapes”, which are shallow depressions scratched in gravel or other debris. They may also use old nests that were built by other birds. For example, one of the Ottawa pairs uses an abandoned raven’s nest.
Females lay two or four mottled, brown eggs in the spring and incubate them for 30 to 35 days, with some help from the male.
Chicks take their first flight about 40 days after hatching. They are dependent on their parents for food until they learn to hunt at about 9 to 12 weeks. The young falcons disperse or migrate at the end of the summer, and eventually establish their own territories.
Canada’s Peregrines vary in their migration patterns. Some winter as far away as South America, while others do not migrate.
Averages 4 or 5 years in the wild. Mortality among juveniles is very high, but Peregrines can live 15 years or longer. Connor, Ottawa’s longtime resident male, was at least 15 when he disappeared in 2012.
Threat of Extinction
North American populations were decimated in the 1940s, ’50s and ’60s by the widespread use of chlorinated hydrocarbon pesticides such as DDT. These compounds travelled up the food chain, so Peregrines accumulated the combined residues not only of their own prey, but also of their prey’s prey. This caused thinning of eggshells, egg breakage, and reproductive failure.
They have also been affected by the destruction of breeding sites and breeding areas, and by human intrusion near nest sites.
DDT use was restricted in Canada in 1969, and in 1972 in the U.S. Recovery efforts, including captive breeding and release programs, monitoring and nest site protection, have improved their status. As of 2005, there were about 800 nesting pairs in Canada. They are currently listed as a species of special concern in Canada.
Current Environmental Threats
Toxins continue to be a problem*, and a bird-control compound called Avitrol (4-Aminopyridine) has been identified as a threat. It is described as a frightening agent and is often used on pigeons. It affects the brain, and birds under its influence behave erratically and emit alarm calls, causing the flock to disperse.
Although not intended to be lethal when used as directed, Avitrol may cause disorientation resulting in accidents and death. There are concerns that predators like Peregrines are exposed by eating Avitrol-intoxicated birds. Even slight disorientation due to trace amounts of Avitrol may be fatal when flying at high speed**.
* Toxicological Profile: for DDT, DDE, and DDE. Agency for Toxic Substances and Disease Registry, September 2002
** Avitrol. Canadian Cooperative Wildlife Health Centre Newsletter, Volume 12, Number 1, Spring-Summer 2006