Once an eagle spots a fish swimming or floating near the water surface, it approaches its prey in a shallow glide and then snatches the fish out of the water with a quick swipe of its talons. Eagles can open and close their talons at will; although, a hungry eagle can be dragged into the water when refusing to release a heavy fish. Unfortunately, the eagle might drown during the encounter with the fish; eagles are strong swimmers, but if the water is very cold, the bird might be overcome by hypothermia.
If an eagle falls into the water during an aerial fight over food with another eagle or accidentally falls into the water, they are able to take flight from the water surface.
The hunting area or home range patrolled by a bald eagle varies from 1,700 to 10,000 acres, though can be smaller where food is prevalent larger quantities.
For a scavenger like the bald eagle, a seal or deer carcass would be an unexpected large food supply. Rich in protein, the bodies will feed a group of eagles for days. Though many calories will be obtained, they will be lost in fighting over the food.
Because of the energy expended during hunting, an eagle has to spend a lot of time resting quietly. It's estimated that only one out of eighteen attempts at attacking its prey is successful.
Though not as fast as falcons, bald eagles are fast fliers; when diving, where lift is less important than reducing drag, the eagle pulls in its wings to minimize their surface area.
Bald eagles have been seen hunting in pairs.
An eagle protects its food by partially opening its wings or tenting.
An eagle can consume one pound of fish in about four minutes; the eagle holds its prey with one talon, holds onto its perch with the other, then tears off each bite with its beak.
Being opportunists, a bald eagle will steal food from other bald eagles as well as other species. Chasing another raptor is usually enough to persuade it to drop its kill, but occasionally a bald eagle will attack. Bald eagles do not have to eat every day, but if the bird goes too long without food, it may not be able to hunt effectively enough to survive.
Eagles have an out pouching of the esophagus, called a crop, where they can store food when the stomach is full. The crop also separates indigestible substances, such as feathers, fur, and scales from the meat. The indigestible substance is mixed with mucus and formed into a mass. After the meal, the eagle eventually regurgitates the mass as a casting.