- 28–37.8 in
- 80.3 in
- 105.8–222.2 oz
- Relative Size: One of the largest birds in North America, wingspan slightly greater than Great Blue Heron.
- Pygargue à tête blanche (French)
- Águila cabeza blanca (Spanish)
- Rather than do their own fishing, Bald Eagles often go after other creatures’ catches. A Bald Eagle will harass a hunting Osprey until the smaller raptor drops its prey in midair, where the eagle swoops it up. A Bald Eagle may even snatch a fish directly out of an Osprey’s talons. Fishing mammals (even people sometimes) can also lose prey to Bald Eagle piracy. See an example here.
- Had Benjamin Franklin prevailed, the U.S. emblem might have been the Wild Turkey. In 1784, Franklin disparaged the national bird’s thieving tendencies and its vulnerability to harassment by small birds. "For my own part,” he wrote, “I wish the Bald Eagle had not been chosen the Representative of our Country. He is a Bird of bad moral Character. He does not get his Living honestly. … Besides he is a rank Coward: The little King Bird not bigger than a Sparrow attacks him boldly and drives him out of the District.”
- Sometimes even the national bird has to cut loose. Bald Eagles have been known to play with plastic bottles and other objects pressed into service as toys. One observer witnessed six Bald Eagles passing sticks to each other in midair.
- The largest Bald Eagle nest on record, in St. Petersburg, Florida, was 2.9 meters in diameter and 6.1 meters tall. Another famous nest—in Vermilion, Ohio—was shaped like a wine glass and weighed almost two metric tons. It was used for 34 years until the tree blew down.
- 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, and birds from California have reached Alaska.
- Bald Eagles can live a long time, with a longevity record of 28 years in the wild and 36 years in captivity.
- Bald Eagles occasionally hunt cooperatively, with one individual flushing prey towards another.
Bald Eagles typically nest in forested areas adjacent to large bodies of water, staying away from heavily developed areas when possible. Bald Eagles are tolerant of human activity when feeding, and may congregate around fish processing plants, dumps, and below dams where fish concentrate. For perching, Bald Eagles prefer tall, mature coniferous or deciduous trees that afford a wide view of the surroundings. In winter, Bald Eagles can also be seen in dry, open uplands if there is access to open water for fishing.
Fish of many kinds constitute the centerpiece of the Bald Eagle diet (common examples include salmon, herring, shad, and catfish), but these birds eat a wide variety of foods depending on what’s available. They eat birds, reptiles, amphibians, invertebrates such as crabs, and mammals including rabbits and muskrats. They take their prey live, fresh, or as carrion. Bald Eagles sometimes gorge, ingesting a large amount of food and digesting it over several days. They can also survive fasting for many days, even weeks.
- Clutch Size
- 1–3 eggs
- Number of Broods
- 1 broods
- Egg Length
- 2.3–3.3 in
- Egg Width
- 1.9–2.5 in
- Incubation Period
- 34–36 days
- Nestling Period
- 56–98 days
- Egg Description
- Dull white, usually without markings.
- Condition at Hatching
- Covered with light-gray down; eyes brown; gape, legs, and skin pink.
Bald Eagles build some of the largest of all bird nests—typically 5 to 6 feet in diameter and 2 to 4 feet tall, and ranging in shape from cylindrical to conical to flat, depending on the supporting tree. Both sexes bring materials to the nest, but the female does most of the placement. They weave together sticks and fill in the cracks with softer material such as grass, moss, or cornstalks. The inside of the nest is lined first with lichen or other fine woody material, then with downy feathers and sometimes sprigs of greenery. Ground nests are built of whatever’s available, such as kelp and driftwood near coastal shorelines. Nests can take up to three months to build, and may be reused (and added to) year after year.
Bald Eagles nest in trees except in regions where only cliff faces or ground sites are available. They tend to use tall, sturdy conifers that protrude above the forest canopy, providing easy flight access and good visibility. In southern parts of their range, Bald Eagles may nest in deciduous trees, mangroves, and cactus. It’s unknown whether the male or the female takes the lead in selecting a nest site. Nests are typically built near the trunk, high up in the tree but below the crown (unlike Osprey nests).
Bald Eagles are powerful fliers—soaring, gliding, and flapping over long distances. In one of several spectacular courtship displays, a male and female fly high into the sky, lock talons, and cartwheel downward together, breaking off at the last instant to avoid crashing to earth. Bald Eagles frequently harass birds including Ospreys and other eagles to steal their food, and occasionally do the same to mammals such as river or sea otters. On the ground, Bald Eagles walk in an awkward, rocking gait. Capable of floating, a Bald Eagle may use its wings to “row” over water too deep for wading. Though often solitary, Bald Eagles congregate by the scores or even the hundreds at communal roosts and feeding sites, particularly in winter. These groups can be boisterous, with birds jostling for position and bickering over prey. During breeding season you may see Bald Eagles defending their territories from a variety of intruders, including raptors and ravens, coyotes and foxes. When feeding at carcasses, Bald Eagles may push Black and Turkey Vultures out of the way; other species including ravens, coyotes, bobcats, and dogs sometimes hold their own. Bald Eagles are often harassed or chased by their fellow raptors and by songbirds including blackbirds, crows, and flycatchers.
The Bald Eagle’s recovery is a spectacular conservation success story. Once abundant in North America, the species became rare in the mid-to-late 1900s—the victim of trapping, shooting, and poisoning as well as pesticide-caused reproductive failures. In 1978 the bird was listed for protection under the Endangered Species Act. Since 1980, gentler treatment by humans along with the banning of DDT (the bird’s main pesticide threat) have led to a dramatic resurgence. By the late 1990s, breeding populations of Bald Eagles could be found throughout most of North America. In June 2007, the bird’s recovery prompted its removal from the Endangered Species list. Continuing threats to Bald Eagle populations include lead poisoning from ammunition in hunter-shot prey, collisions with motor vehicles and stationary structures, and development-related destruction of shoreline nesting, perching, roosting and foraging habitats. They are still vulnerable to environmental pollution, as evidenced by the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska. An estimated 247 Bald Eagles died from oil exposure. Population levels in the Sound decreased by almost four percent the following year. The local population returned to pre-spill levels by 1995. Today there are about 250,000 Bald Eagles, according to estimates by Partners in Flight, with 88 percent spending part of the year in the U.S., 31 percent in Canada, and 8 percent in Mexico. They are not on the 2012 Watch List.
- Buehler, D. A. 2000. Bald Eagle (Haliaeetus leucocephalus). In The Birds of North America, No. 564 (A. Poole and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.
- Dunne, P. 2006. Pete Dunne’s Essential Field Guide Companion. Houghton Mifflin, New York.
Resident to long-distance migrant. Complex migration patterns depend on age, breeding location, and food availability. Northern adults begin fall migration when lakes and rivers freeze, usually migrating coastward or to open water. They return to breeding grounds when weather and food permit, usually January–March.
Find This Bird
To find Bald Eagles, head for water, where the birds are likely to be looking for fish. Nationwide, Bald Eagles are most widespread during winter, where they can be found along coasts, rivers, lakes, and reservoirs in many states. They winter in large numbers at some lakes and national wildlife refuges—this list from the National Wildlife Federation is a good place to start.