For much of the 20th century, peregrine falcons were at risk of being extirpated (locally extinct) in the U.S. and Canada. Falcons were dying off and breeding pairs were unsuccessful. What was happening to the peregrine falcons?
The cause of the peregrine falcon disappearance was pesticides, specifically DDT. In the middle of the century, DDT was sprayed on farmland and the chemical made its way into the food chain. Peregrine falcons are top predators and thus absorbed large amounts of DDT from their prey like fish and other birds.
DDT poisons adult falcons and also causes thinning of their egg shells, preventing the offspring from developing. Not only do the adults die, but their offspring cannot develop in the egg. Since the banning of DDT in the 1970’s, peregrine falcons have steadily increased to the level that they are no longer on the Endangered Species List.
Description: Peregrine falcons are large, quick predatory raptors. They are about 1 ½ feet tall with a wingspan of 3 ½ feet. Their strong, sharp yellow talons allow peregrine falcons to capture other birds, even in flight.
Peregrine falcons can be hard to identify because of their quick flight and camouflage coloring. The wings and tail are bluish-gray, while the back is a darker brown.
The easiest way to identify a peregrine falcon is to look for these markings:
- A yellow circle surrounding each eye.
- Dark brown bars across the white chest.
- The chin and neck are white, but the cheeks and top of the head are brown. Sometimes the cheeks can have a dark brown tear-shaped mark.
- If the wings are open, you can see the dark brown barring across the wings.
Habitat and Range: With their global range, peregrine falcons can be found in a variety of habitats, including mountains, forests, cities, valleys, deserts, and coastlines. North American peregrine falcons can be migratory or non-migratory. Some live year-round in Alaska, the Midwest, the Northeast, the Southwest and along the western coastline. Other peregrine falcons migrate from South America and the Gulf Coast to the Alaskan tundra each year.
Peregrine falcons are global birds. They are found on every continent except Antarctica. Peregrine falcons can travel long distance, sometimes between continents, to get from their wintering grounds to their breeding grounds.