The Nature Conservancy. Protecting nature. Preserving life.™

Journey with Nature logo TNC

American Peregrine Falcon Quick Facts

Scientific name: Falco peregrinus anatum
Size: 15 - 20 inches long
Wingspan: 38 - 44 inches wide
Weight: 1.25 - 2.75 pounds
Plumage: dark blue-grey, black mustache mark, black bars on chest, long pointed wings
Habitat: found throughout the U.S.
Nesting: varies; mostly on cliffs but also found in cities, using tall structures
Behavior: forager, bird of prey
Diet: carnivorous -  other birds like songbirds and waterfowl; sometimes bats and small mammals
Threats: larger birds of prey are known to eat young peregrines; man

The American peregrine falcon is a stunning creature in flight. Wings span at an average of 40 inches, are pointed and sleek with a swept-back look. The body and crown is a dark blue-grey with a contrasting white or buff underside marked with short, black bars. A mustache-like marking and a sharply hooked beak distinguishes this elegant bird of prey from others.

The plumage of the peregrine falcon isn't the only way it distinguishes itself from other birds; the bird is breathtakingly fast. At normal flight the falcon can reach an average speed of 40 mph and when in the chase, it can reach as high as 65 mph. Even more impressive is when it's on the hunt; it can dive towards its prey at speeds over 200 mph making it the fastest bird in the world.

Threats to the Peregrine Falcon

Peregrines are fast, aggressive creatures and are on top of their food chain. While young peregrines are preyed upon by golden eagle and great-horned owls there are few threats towards the adults other than man.

By the mid 1960's, there were no peregrines in the eastern United States and the decline spread westwards so that by the mid-70's western populations had declined by up to 90 percent. It was estimated that 3,875 nesting pairs were found in North America prior to the 40's; by 1975, only 324 pair existed in the US. Loss of habitat, shootings, egg collecting and other human disturbances had weakened North American populations for decades but drastic declines didn't occur until after the widespread use of a popular insecticide - DDT. Like the canary in the coalmine, the peregrine falcon provided humans a warning as how chemical pollution can disrupt the environment and the life around it.

DDT & Peregrine Falcon Population Decline 

The use of dichlorodiphenyltrichloroethane, or DDT, began during World War II as an extremely effective pesticide. Its use continued after the war as a way to control agricultural pests and in killing malaria-carrying mosquitoes. Unfortunately it would be years later before it was understood that DDT would have adverse effects on a variety of ecologically important insects, birds and the environment. Bats, fireflies and peregrine falcons were just a few species that were greatly affected.

For the peregrine falcon, DDT poisoning was due to its being on top of the food chain. After consuming other birds that fed on seeds, insects and fish contaminated with DDT, the poison eventually accumulated in its system. High concentrations of a DDT metabolite called DDE prevented normal calcium production causing thin, frail eggshells that would break under the weight of the parent during incubation. Because of the toxic contaminant, many eggs did not hatch and the populations precipitously dropped until a mere 12% of normal peregrine falcon populations remained in the United States.

Saved from the Brink of Extinction

In 1970, the American peregrine falcon was listed as endangered under the Endangered Species Conservation Act of 1969 (and then again in 1973 when the Endangered Species Act passed). Encouraged by the EPA's banning of DDT in 1972, recovery projects began to take shape. Beginning in 1974, The Peregrine Fund, along with various national and state agencies in both the United States and Canada, embarked on a reintroduction program for the peregrine falcon.

Thanks to the scientists and researchers at Cornell University, adult birds were successfully bred in captivity. After the eggs hatched, they were raised in the labs until three weeks old. They were then placed in hack sites (artificial nesting sites) where they were fed and cared for by unseen benefactors until flight and hunting skills were developed enough for them to become independent. More than 6,000 American peregrine falcons have been released in North America since 1974 due to the cooperative efforts among federal and state Fish & Wildlife Services, The Peregrine Fund, Midwestern Peregrine Falcon Restoration Project and the Santa Cruz Predatory Bird Research Group. 

The success of these recovery programs allowed the declassification of the peregrine falcon as a federally endangered species in 1999. Although the bird of prey remains federally protected under the Migratory Bird Treaty Act and will be monitored until 2015, the survival of the peregrine falcon marked the most dramatic success of the Endangered Species Act.

Indiana's Peregrine Falcon Reintroduction Program

In 1991, Indiana began peregrine falcon reintroductions with the release of 15 young birds in Indianapolis. Over the next three years, additional releases occurred in the Fort Wayne, South Bend and Evansville areas. The towns were chosen because of the availability of food and tall buildings for the falcon to nest. The reintroduction program has been successful with a total of 60 falcons released between 1991and 2005.

According to DNR's Peregrine Falcon Reintroduction Program, a record of 13 active pairs was found in Indiana in the past year. Active pairs allude to the fact the peregrine falcons were mating, increasing the chances of better population numbers in Indiana. Statistics look promising with 12 out of 13 couples successful in reproduction and 23 out of the 30 fledglings banded for identification. Banding is necessary in order to monitor the movements and determine of the origins of the birds. According to the report, four of the falcons were originally from Indiana while the remaining came from the surrounding Midwestern states. Eight other peregrines from Indiana were found nesting in Wisconsin, Illinois, Iowa and Ohio.

Between 1989 and 2006, almost 300 peregrine falcon fledglings were born in Indiana. While off the federal endangered list for more than seven years now, the peregrine is still protected under Indiana endangered species legislation until local population goals are met.

Did You Know?

• Peregrine comes from peregrin, meaning "traveler" in Latin. Quite a fitting name for a bird with one of the longest migrations in North America with some trips up to 15,550 miles roundtrip.
• Peregrine falcons are found all over the world with the exception on Antarctica.
• The female is known as the “falcon” while the male is called the “tiercel.” This is due to the fact that males tend to be a third smaller than his mate which is common in birds of prey.
• Pairs mate for life and will usually return to the same nesting site.
• Peregrine falcons do not build stick nests, but instead scrape out depressions on high cliffs. They will use deserted stick nests of other species though. Their nesting sites are called an aerie or eyrie.
• According to the Midwest Peregrine Society, 48% of peregrine nesting sites are located on high-rise buildings and other tall structures in the Midwestern states.
• Falcons have a system of baffles in the nostrils to enable them to breathe during incredibly fast dives.
• Even though DDT has been banned in the U.S. since 1972, other countries which peregrine falcons migrate to still use it as a pesticide.
• DDT can take more than 15 years to break down in our environment. Fish consumption advisories are in effect for DDT in many waterways including the Great Lakes ecosystem.