Peregrine Falcon
Endangered???
In 1994, the Arctic Peregrine Falcon was removed from the list of threatened
and Endangered Species by the US Fish and Wildlife Service, having been on the
list since 1970. (2)
Description
-Arctic peregrine falcons are medium-sized falcons, about 14-18 inches long,
-Adults have blue-gray backs with white chests and heavily-barred bellies.
-Both adults and immatures have dark heads with a distinct mustache mark below
the eye.
Habitats and Habits
- arctic peregrine falcon mostly eats birds that are caught in mid-air chases
of breath-taking speed.
- Nests are on cliffs or bluffs and are usually near rivers or lakes that
provide habitat for the shorebirds, songbirds, and waterfowl upon which the
falcons prey.
- Arctic peregrine falcons nest in the treeless tundra areas of Alaska,
Canada, and Greenland, and migrate south through Canada and the United States.
They spend the winter in warmer climates from the southern United States to
southern Argentina and Chile. In Alaska, arctic peregrine falcons are found
nesting mostly along rivers in northern and western Alaska.
Causes of Decline
The use of DDT and other toxic pesticides was the primary cause of the decline
of peregrine falcons. Pesticides which are used to control insect populations
accumulate in tissues of insect-eating fish and birds. These poisonous
chemicals are further concentrated by raptors that catch or consume insect
eaters. They affect peregrine falcons by directly killing them, altering their
behavior (such as nest defense), and causing females to lay eggs with such
thin shells that the eggs often break before hatching. Restrictions on the use
of these pesticides since 1972 have allowed arctic peregrine falcons to
recover. Currently, about 250 pairs nest in Alaska and thousands nest
throughout arctic North America.
Research and Recovery
Research on arctic peregrine falcons has focused on monitoring changes in
pesticide levels, breeding success, and population size. Although populations
declined due to exposure to environmental contaminants, the recovery of arctic
peregrine falcons has been enhanced through the careful protection of nesting
sites. Cooperative efforts between land management agencies and resource
exploration and development interests have allowed arctic peregrine falcons to
reproduce without disturbance at their remote nesting areas.
Reference
(1)Peregrine Falcon; by Ted Swem
http://www.wildlife.alaska.gov/aawildlife/endangered/concern/ar_falc.cfm
(2) http://earthday.wilderness.org/backyard/amazing/arcticperegrinefalcon.pdf
costiner"at"mit
Last updated: Dec 1,
03