The Peregrine is a crow-sized falcon. A blackish “moustache” (black stripe below the eye) and bluish-grey or slate-coloured upper parts characterize both sexes. The under parts are white to buff with brown bars on the sides and thighs, and spots on the abdomen; the underside of the wings is white with black bars. The young peregrine falcon has a blackish moustache; brownish upper parts; a dark brown tail with buff colored bars and white tips; and buff-colored under parts with blackish-brown streaks.

There are three subspecies of the Peregrine Falcon in North America. The Peregrine Falcon is the most widely-distributed bird of prey species in the world, with races nesting on every continent except Antarctica. Here in North America we have three races of Peregrine. Tundra Peregrines nest in Greenland and across the arctic and subarctic regions of Canada and Alaska. In the winter, individuals of this highly migratory race travel south to the Caribbean, Mexico, Central America and South America, as far south as Argentina and Chile, with many passing along the Maine coast in their journeys back and forth. Darkly-plumaged Peale’s Peregrines are sedentary inhabitants of the wet Pacific Coast of British Columbia and southeastern Alaska.

The pesticide DDT and its by-product DDE accumulated in this falcon’s prey species, causing it to produce thin-shelled eggs. The eggs broke easily during incubation, and few chicks hatched. By 1970, just 90 anatum peregrines remained in Canada, and for more than twenty years no pairs were known to nest on prairie cliffs. Today, however, due to restrictions on DDT use in Canada and the United States, to intensive reintroduction programs across Canada, and to successful captive-breeding programs at Wainwright, Alberta and Saskatoon, Saskatchewan, the anatum Peregrine Falcon is coming back. Its numbers have improved because of recovery efforts and it is now considered nationally threatened rather than nationally endangered.

The peregrine falcon has been removed from the federal Endangered Species list, but it is still protected by state and federal laws.