Bird Species Spotlight: The Bald Eagle

The bald eagle has been the national emblem of the United States since June 20, 1782 when the Continental Congress adopted the design for the Great Seal of the United States depicting a bald eagle grasping 13 arrows and an olive branch with its talons. The bald eagle has been a spiritual symbol for native people for far longer than that. Had Benjamin Franklin prevailed, the U.S. emblem might have been the wild turkey. In 1784, Franklin belittled the national bird’s thieving tendencies and its vulnerability to harassment by small birds. He stated that the bald eagle was a bird of bad moral character and does not get his living honestly. He felt this way because bald eagles will often go after other bird’s catches rather than catch their own prey. For instance, they will routinely harass an osprey until the smaller raptor drops its prey in midair before swooping it up.

Bald eagle perches on a branch.

Bald eagle ready to take flight.

The bald eagle isn’t really bald, but their white-feathered heads gleam in contrast to their chocolate brown body and wings. While both male and female are identical in plumage, the female is about 25% larger than the male. Their eyes are almost as large as a human’s, but their sharpness is at least four times that of a person with perfect vision. If you swapped your eyes for an eagle’s, you could see an ant crawling on the ground from the roof of a ten story building. Objects in your line of sight would appear magnified, and everything would be brilliantly colored and rendered in an inconceivable array of shades including ultraviolet light!

While fish of many kinds are the main diet of the eagle, they will eat a wide variety of foods depending on what is available including birds, reptiles, amphibians, invertebrates such as crabs, and even mammals including rabbits, squirrels, and raccoons. They will take their prey live, fresh, or as carrion.

Bald eagle catches fish for dinner.

Bald eagles typically nest in forested areas adjacent to large bodies of water, staying away from heavily developed areas when possible. The largest bald eagle nest on record was located near me in St. Petersburg, Florida at over nine-feet in diameter and twenty-feet tall. Another famous nest in Vermillion, Ohio was shaped like a wine glass and weighed over 4,000 pounds. This nest was used annually for 34 years until the tree was blown down in a storm.

Both the male and female eagle will bring materials to build the nest, but the female will do most of the placement. They weave together sticks and fill in the cracks with softer material such as moss. Nests can take up to three months to build and may be reused year after year.

Two bald eagles working on their nest.

Bald eagles are sexually mature at four or five years of age. It also takes this long for juveniles to develop adult plumage. When they are old enough to breed, they often return to the area where they were born. While other raptors usually nest in April or May, bald eagles are earlier breeders. They build and reinforce their nests usually by February and lay a clutch of one or two eggs the same month. Incubation is 30–35 days and the eaglets will fledge in another two months or so. Both parents take turns incubating the eggs but the female does most of the sitting.

Bald eagle in flight with nesting material.

Immature bald eagles spend the first four years of their lives in nomadic exploration of vast territories and can fly hundreds of miles per day. Some young birds from Florida have wandered north as far as Michigan, while birds from California have shown up in Alaska.

The average lifespan of bald eagles is around twenty years in the wild, but they can live much longer in captivity. A captive eagle in West Stephentown, New York lived to be at least 48 years old!