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Eagle Survival - Diet

In the wild, and depending on its availabilty, the bald eagle's diet consists of 70-90% fish. Just as humans require a varied and balanced diet, bald eagles do not exist on fish alone. The remaining 10-30% of the eagle diet varies from small mammals to waterfowl to varied forms of aquatic life. This variety contributes to the eagle's health. For instance, occasionally the bald eagle may feed on a rabbit or other small mammal. The bald eagle consumes the bones of fish without problem. However, the bones and fur of the rabbit or other small mammal must be stored in a special section of the bald eagle's throat called the crop. Eventually the fur and bones are semi-digested and form a small pellet which the eagle spits or casts out of its mouth. The dietary change which requires the use of the crop may perform a necessary health function for the bald eagle.

Bald eagles are known as opportunistic feeders. Coming from a family that includes the vulture, bald eagles share the familial tendency to feed on carrion, or dead animals such as road kill when it is necessary or available. In the past, bald eagles have been disparaged by such notable figures as Benjamin Franklin for their habit of stealing food literally from the mouths of the osprey. Scientists believe that these opportunistic feeding behaviors may be indications of a time when the bald eagle did not reign at the top of its food chain. Scientists think that the bald eagles that were able to fend for themselves and find food by whatever means necessary survived through the ages by acquiring these feeding behaviors.

The dietary needs of the bald eagle motivate other behaviors such as its winter migration. Bald eagles that live in the warmer areas of Florida stay in the same territory year round. But bald eagles in northern, colder climates migrate south to locate more accessible food sources when rivers and lakes freeze in northern areas.