Bald Eagle

Bald Eagle

[ Haliaeetus leucocephalus ]

Quick Facts

BODY LENGTH: 32 inches
WEIGHT: 10 to 12 pounds for females, slightly less for males
WINGSPAN: close to 7 feet (sometimes as large as 10 feet)
WILD DIET: fish, small mammals, birds, and carrion
ZOO DIET: carnivore and bird of prey diet, fish, and small rodents
DISTRIBUTION: throughout North America, from the edge of the tundra/forest line in Alaska and Canada, south to the Gulf of Mexico, and into northern Mexico
HABITAT: wooded areas along large streams, rivers, and lakes where fish are abundant

A Symbol with a Story

Big bird

Bald eagles are large birds of prey (called raptors) that patrol the skies of North America, from Alaska to Northern Mexico. They have a wingspan of nearly seven feet, though some birds have wingspans of more than 10 feet! This makes the bald eagle the second largest raptor in North America, after the California condor. Females are slightly larger than males, a common characteristic in raptors. Bald eagles have a distinctive white feather pattern on the head and neck. From a distance, this gives them a "bald" appearance, and led to their name.

Fishing on the wing
Fish are the favored food of bald eagles, but they also eat ducks, rabbits, squirrels, opossums, and deer fawns. Whatever the prey, they use their incredible eyesight to spot a potential meal from high in the sky. Then they swoop down at high speed and grasp the victim in their strong talons. It's a spectacular sight to see a bald eagle pluck a fish from a lake's surface. Bald eagles eat carrion (or dead animals) found along roads or the banks of bodies of water. Sometimes they steal prey caught by other predators. 

Big nest
Bald eagles are big birds, but their nests are completely off the chart! One nest weighed well over a ton. The nest is called an "eyrie" and is usually built in the tallest tree along streams, rivers, or lakes. Bald eagles use the same nest year after year, and keep it in good condition by continually adding new branches for support---that's how the nests reach such tremendous size.

The female bald eagle lays a pair of white to bluish eggs in the nest. She and her mate share incubation duties, which last up to 35 days, when the eggs hatch. When the nestlings hatch, both the male and female take care of the tiny birds for the three months or so before they are ready to fly.

On the brink
The story of the symbol of our country has become famous. Fortunately, the story has a happy ending. By the 1960s, bald eagles were in serious trouble. Their numbers had declined so severely that there was a good chance the symbol of the U.S. could become extinct.

The problem began in the 1800s, as people moved west and the natural habitat declined. But the biggest cause of the decline was the use of DDT, a pesticide that was sprayed on plants. The plants were eaten by small animals, which were eaten by eagles and other raptors. The chemical also ran into the waterways, where it was stored up in the fat tissue of fish eaten by the eagles. As a predator at the top of the food chain, the pesticide reached its highest concentrations in bald eagle populations. DDT poisoned the birds themselves, but it also made their eggs' shells too thin. When the parents tried to incubate the eggs, the shells broke.

People were concerned about bald eagles, and the birds were declared an endangered species. Once DDT was found to be the culprit, the pesticide was banned. Bald eagles began the slow road to recovery. By 1995 populations had increased enough to remove bald eagles from the Endangered Species List.

Bald eagles at Brookfield Zoo
Bald eagles can be found at Great Bear Wilderness.

Get Involved

Conservation Fund of the Chicago Zoological Society