Peregrine Falcons

With a wingspan of about 40 inches, the peregrine falcon is among the world’s fastest birds, flying at 40–55 mph and diving at more than 200 mph when striking avian prey in mid-air. Of the three North American subspecies, the American peregrine falcon (Falco peregrinus anatum) has the broadest distribution and a range that included the Greater Yellowstone Ecosystem (GYE). Peregrine populations began to decline rapidly in the late 1940s because of pesticide contamination. The American peregrine falcon was considered extirpated in the GYE by the 1960s and listed as endangered in 1970. As part of a national reintroduction program, peregrines were released in Bighorn Canyon, Grand Teton, and Yellowstone during the 1980s. They usually nest on cliff ledges and may reuse the same eyrie for many years. They typically reside in the GYE only from March through October to nest when their favored prey—songbirds and waterfowl—are most abundant. During winter they may migrate as far south as Mexico. American peregrine falcons were removed from the list of endangered species in 1999 and post-delisting monitoring continues.

 
Updated 4/30/08