Tiercel – Male Peregrine Falcon

The female peregrine 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 the females, which is common in birds of prey.

What Makes Peregrine Falcons Special?

The peregrine falcon is breathtakingly fast, when it’s on the hunt it can dive towards prey at speeds over 200 mph making it the fastest creature in the world.

The peregrine falcon is a stunning creature in flight. Its pointed, sleek wings have an average span of 40 inches. Its body and crown is dark blue-grey with a contrasting white or buff underside marked with short, black bars. A moustache-like marking and a sharply hooked beak distinguish this elegant bird of prey.

Peregrines are fast, aggressive creatures at the top of their food chain. Humans are the only significant threat to adult peregrines.

DDT and Peregrine Falcon Population Decline

Dichlorodiphenyltrichloroethane, or DDT, came into wide use during World War II as an extremely effective pesticide. Its use continued after the war to control agricultural pests and malaria-carrying mosquitoes. Unfortunately, it took years for people to realize that DDT had adverse effects on a variety of ecologically important insects and birds and other animals.  DDT poisoning was especially harmful to the peregrine falcon that sit at the top of the food chain. The poison accumulated in the peregrine’s system after they consumed other birds that fed on seeds, insects and fish contaminated with DDT. 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. Many eggs did not hatch and the populations precipitously dropped until a mere 12 percent of the previous peregrine falcon populations remained.

The Great Survivor 

In 1970, the American peregrine falcon was listed as endangered. under the Endangered Species Conservation Act of 1969 (and it was listed again in 1973 when the Endangered Species Act passed). After DDT was banned in 1972, recovery projects began to take shape. Reintroduction programs for the peregrine falcon began to successfully breed in captivity. After the eggs hatched, they were raised in the lab until they were three weeks old. They were then placed in artificial nesting sites where they were fed and cared for by unseen humans until their flight and hunting skills were developed enough for them to become independent.

The success of these recovery programs allowed the declassification of the peregrine falcon as an endangered species in 1999. Peregrine comes from peregrin, meaning traveler in Latin. Quite a fitting name for a bird with one of the longest migrations with some trips up to 15,550 miles round-trip. Peregrine falcons are found all over the world with the exception of Antarctica. 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. However, they will use deserted stick nests of other species. Their nesting sites are called aeries or eyries. According to the Midwest Peregrine Society, 48 percent of peregrine nesting sites in the midwestern states are located on high-rise buildings and other tall structures. 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, peregrine falcons migrate to other countries where it is still in use as a pesticide.

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 the chest, long pointed wings
Nesting and habitat: 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: humans