What Do Bald Eagles Eat? Fish, Waterbirds and Carrion

Fish: the bald eagle’s main food

The bald eagle is a sea eagle, and fish are at the heart of its diet. In a review of 20 diet studies across North America, fish made up about 56% of prey items at nests, birds about 28%, mammals about 14% and other animals about 2%. In some places the share of fish is much higher: around 78% of nest prey in southeast Alaska and about 90% of the diet along Oregon’s Columbia River estuary.

More than 100 fish species have been recorded. Common ones include:

• Salmon and trout along the Pacific coast and in Alaska.
• Herring, sand lance and other schooling fish in coastal bays.
• Shad, suckers, carp and catfish in rivers, lakes and reservoirs.
• Mullet and catfish in Florida.

Bald eagles take bigger fish than most other fish-eating birds in North America. Most prey fish are 20–75 cm (8–30 in) long, and eagles seem to prefer fish around 35 cm (14 in). Heavier fish can be grabbed but not lifted, so the eagle may drag them across the water to shore.

How bald eagles catch fish

A bald eagle usually hunts from a high perch overlooking the water, or by soaring and scanning from above. When it spots a fish near the surface, it glides down at a shallow angle, swings its feet forward and grabs the fish without stopping, then flies off with it.

Unlike an osprey, which plunges feet-first and may go completely underwater, a bald eagle rarely submerges. It takes fish that are swimming near the surface, stunned, dying or already dead and floating. Spiky scales called spicules on the soles of its feet, and long curved talons, help it grip slippery prey. For comparison, see how do ospreys catch fish?.

Bald eagles are also flexible. They wade into shallow water to catch spawning fish, pick fish from shallow pools, and gather below dams and spillways where turbines stun or kill fish. In one study on the Columbia River, about 58% of fish were caught alive, 24% were scavenged and 18% were stolen from other animals.

Food piracy: stealing from ospreys and others

Bald eagles are famous for kleptoparasitism, which means stealing food that another animal has caught. Their favorite victims are ospreys. When an osprey rises from the water with a fish, an eagle may chase it, swooping and harassing until the osprey drops its catch, which the eagle then grabs, sometimes in midair.

Eagles also steal from gulls, herons, otters and other eagles, and in winter they may pirate prey from hawks and falcons. Adults are more skilled hunters, while young eagles rely more on scavenging and theft. This habit is why Benjamin Franklin called the bald eagle a bird of poor character, but for the eagle it is a sensible way to save energy.

Birds, mammals and other prey

When fish are scarce or hard to reach, bald eagles switch to other prey:

• Birds: mainly medium-sized waterbirds such as ducks, coots, grebes and gulls. At seabird colonies, eagles take adults, chicks and eggs. Occasionally they kill geese, herons or other birds of prey.
• Mammals: rabbits, hares, muskrats, squirrels and prairie dogs, especially inland in winter. Bald eagles sometimes hunt in pairs, with one bird distracting the prey while the other attacks.
• Reptiles: turtles are a regular food in some areas. In coastal New Jersey, turtle remains were found in 14 of 20 eagle nests studied. Snakes and lizards are taken less often.
• Invertebrates: in Alaska, eagles pick up crabs, mussels, sea urchins and other shellfish along the shore.

Bald eagles do sometimes take very young lambs or small pets, but such cases are rare. They are far less likely to attack live livestock than golden eagles, which hunt more mammals; see what do golden eagles eat?.

Salmon runs and winter feeding

Food availability shapes where bald eagles spend the winter. In the Pacific Northwest and Alaska, eagles gather in large numbers along rivers where salmon die after spawning. On British Columbia’s Squamish River, one to two thousand eagles may gather between November and February, and the Chilkat River near Haines, Alaska, hosts one of the largest gatherings in the world each fall.

Most salmon taken at these rivers are already dead or dying, so the eagles are mainly scavenging. In the interior of the continent, where lakes freeze, eagles concentrate below dams and along stretches of open water, or move away from water to feed on rabbits, prairie dogs and carcasses of deer and livestock.

When food is plentiful, an eagle can eat a large meal and store up to about 1 kg (2.2 lb) of food in its crop, a pouch in the throat. This lets it go several days without feeding if the weather turns bad.

How much can a bald eagle carry?

Bald eagles can kill prey heavier than they can lift. In normal flight, large eagles can usually carry only around half their body weight, which for a bald eagle means about 2–3 kg (4–7 lb). Heavier fish or birds are eaten on the spot, dragged to shore or abandoned. For more on lifting limits and myths, see how much weight can an eagle carry?.