Description

Peregrine falcons are among the most famous birds of prey in North America. They have a long association with humans and have been prized by falconers since ancient times.  Peregrines can reach speeds of more than 320 kph when diving or 'stooping' at their prey. These swift birds are about the same size as a crow.  Their long pointed wings allow them to maneuver quickly. Peregrines have slate gray upper-parts and white undersides with black bars across the chest, thighs and undersides of the wings. Some have a distinctive blackish bar, called a malar stripe, that extends down each check from under the eye.  Others have a complete cap. Young peregrines have dark brown upper-parts.  There are large colour and size variations in peregrine falcons; up to 19 subspecies are recognized in the world, with three in North America.  As more genetic studies are performed, however, some subspecies can be reconsidered. For example, a recent study on North American peregrine falcons has shown that the two subspecies present in the NWT, anatum and tundrius, are actually genetically the same.   

Distribution

Peregrines are found throughout the world.  The NWT is home to two of the three subspecies found in Canada.  The anatum subspecies is found below the treeline, with a large population located along the Mackenzie River Valley.  Anatum also live in southern Canada and the U.S.  The tundrius subspecies is found from the treeline to the arctic coast and Arctic Islands. Canadian peregrines migrate to Central America or northern South America in the winter.

NOTE: Click on map for full view. Distributions are approximate and not intended for legal use. (JPG = 2031 KB)

Population Size and Trends

The historical population estimate of peregrine falcons in North America is about 5,000 birds.  Local populations in Canada suffered a massive reduction between the 1950s and 1970s.  However, since the mid-70s, the peregrine population in Canada has increased dramatically.  From 1995 to 2005, the number of nesting pairs with eggs in a study area along the Mackenzie River Valley increased from 58 to 78.  There were only 16 pairs in 1975. 

Peregrines have three main habitat requirements.  They need proper nesting sites, usually on cliff ledges near water.  They also need nesting ranges.  These ranges are actively guarded and can extend up to one kilometre from the nest.  The third requirement is a home range.  The birds don't defend this range but they do hunt within it.  The home range overlaps the nesting range and can extend up to 27 kilometres from the nest.  Peregrines mainly hunt other birds in the air, so open tundra, savanna, prairies and waterways are important habitats.

Wild peregrines live an average of five years.  They begin breeding in their second year.  Peregrines perform an elaborate courtship ritual that lasts a few weeks. In the NWT, two to four eggs are laid between May and early June.  Eggs are incubated by both parents for an average of 36 days.  After hatching, the female cares for the chicks while the male brings her food. The female resumes hunting once the chicks are about 15 days old.  Peregrine chicks begin to fly about 35 to 40 days after hatching.  Adults continue to feed the chicks for five to six weeks after they fledge.  Peregrines feed on many types of birds including perching birds, waterfowl and shorebirds.  They are opportunistic feeders and will take small mammals when they can.

Pesticides were the major contributors to the drop in Peregrine Falcon numbers between the 1950s and 1970s.  Because they are at the top of the food chain, chemicals ingested by their prey become concentrated in peregrines.  This is especially true for organochloride compounds such as DDT, which are stored in the falcon’s fat.  These chemicals inhibit eggshell production leading to thin-walled eggs and higher egg mortality.  Because of their short lifespan and high adult mortality, females need to produce an average of 2.2 chicks a year if the population is to remain stable.  The effects of DDT tend to reduce the number of chicks per year to below this number.

Peregrines are protected in Canada by provincial and territorial legislation.  It is illegal in the NWT to hunt or possess live peregrines.  It is also illegal to possess whole or parts of dead peregrines.  Exporting peregrines or peregrine parts is prohibited by the Convention in International Trade of Endangered Species (CITES).  The anatum peregrine falcon was designated as Endangered by COSEWIC in 1978 due to declining populations.  It was downlisted to Threatened in 1999 after a population increase.  COSEWIC designated the tundrius peregrine falcon as Threatened in 1978.  It was downlisted to Vulnerable in 1992 as populations stabilized or increased. In 2007, COSEWIC re-assessed the status of all peregrine falcons in Canada, and merged anatum and tundrius into one entity that was downlisted to Special Concern.  

Peregrine numbers have been (deleted word) increasing since the mid-1970s due to the North American ban on organochloride pesticides.  The Canadian Wildlife Service, provincial agencies and the Government of the Northwest Territories (GNWT) are active participants in the Anatum Peregrine Falcon Recovery Plan implemented in 1988.  Under this plan, peregrine nesting grounds across North America, including the Mackenzie River Valley, have been surveyed every five years since 1975.  The GNWT is committed to preserving peregrine nesting habitat and protecting all birds of prey from human disturbances.  

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       Site last updated Tuesday, February 19, 2008