A peregrine falcon often watches for prey from a high perch, such as a cliff or a tall tree. Then it hunts by diving down from high above. About 450 species of birds in North America have been documented as peregrine falcon prey. Worldwide, the number may be as many as 2,000. Peregrines hunt birds as large as sandhill cranes and as small as hummingbirds. People have trained peregrine falcons for falconry for many centuries. Trained peregrine falcons are sometimes flown by their trainers at airports to scare off birds that could collide with a plane.

In North America a peregrine falcon is roughly crow sized. Males are 36 to 49 centimeters long. Females are 45 to 58 centimeters long, with a wingspan of 91 to 112 centimeters. North American peregrines weigh an average of 907 grams. Females are typically 40 to 50 percent heavier than males. There are 19 regional variants, called subspecies, and they vary considerably in size and color. In cities, peregrine falcons nest on ledges of tall buildings and eat pigeons.

In the middle of the 1900s the pesticide DDT made peregrine falcon eggshells thin, and the eggs broke while the parents sat on them. In 1970 there were 39 known pairs of peregrine falcons in the lower 48 states. The species was gone east of the Mississippi River. The United States banned the use of DDT in 1972. By August 1999 The Peregrine Fund and others had released over 4,000 captive-raised peregrine falcons in 28 states, after 28 years of effort. In 1999 the peregrine falcon was taken off the United States list of endangered species.

Peregrine falcons form pairs that often last through many breeding seasons, and both sexes have a strong attachment to previous nesting sites. Some nest sites are used again and again for many years. A peregrine falcon does not build a nest. It lays its eggs in a scrape, a small dip in the soil or gravel of a ledge. It lays one egg every 48 hours, for a total of 2 to 6 eggs. The eggs hatch in 33 to 35 days. A male brings food to the female and to the young at the nest. Young peregrine falcons are ready to fly about five to six weeks after they hatch.

Peregrine falcons live on every continent except Antarctica. They like open country. Some peregrine falcons migrate and some stay in one place all year. Peregrines that nest on Arctic tundra and winter in South America can fly more than 15,000 miles in a year. In a typical year, most peregrine falcons do not live to be 1 year old. A healthy falcon that survives lives an average of 13 years.

Words to know

• subspecies: regional variant
• falconry: training falcons
• scrape: small dip
• perch: high seat
• species: kind of animal