The Bald Eagle

The bald eagle is the only eagle which is found exclusively in North America. It lives from Alaska all the way south to northern Mexico. The bald eagle really is not bald. The word used to mean 'white'. Its head is white. About seventy thousand bald eagles exist in the world today. One-half of them are in Alaska. Another twenty thousand live in British Columbia which is on the western coast of Canada. They survive well in those areas mainly due to the salmon. Their best food source is dead or dying fish.

Bald eagles are a part of a family which includes hawks, kites, and old-world vultures. Based on physical character and behavior, scientists divide eagles into four types. The bald eagle is in the group of sea or fish eagles.

Both male and female bald eagles have the same coloring. They have yellow eyes. Their feet, legs, and beak are yellow also. Their heads, necks, and tails are white. Their breasts and back are blackish-brown. Young bald eagles have different coloring. Their beaks are black. Their eyes are brown. Their feathers are a mixture of brown and white.

Bald eagles change over the course of five years until they develop the white head and tail feathers. A leucistic bald eagle has a genetic mutation which displays white patches on its body and wings. It could also have faded or pale feathers. No other large birds in North America have blackish-brown feathers and a white head and tail.

A bald eagle's bones and therefore skeleton is very lightweight. Its skeleton may weigh five ounces. The bones are hollow. The feathers weigh twice as much as the skeleton. Its talon, feathers, and beak are made of keratin, the same substance as the fingernails of a human. Because they eat mainly fish, bald eagles live along the coasts or on lakes and rivers. The average lifespan of a bald eagle is fifteen to twenty years.

Bald eagles are at the top of the food chain. They have no predators. They are more apt to get chemicals built up in their bodies because each step of the food chain before them ingests a little more of the chemical. When it reaches the eagle, the amount of chemical is very strong.

A bald eagle can lift a weight up to four pounds. Therefore, their prey is mainly small animals. Sometimes, like vultures, they eat carrion, dead animals which they find on the ground. An eagle's eye is about the same size as that of a human. Its vision, however, is four times as sharp.

Since eagles don't have vocal cords, they do not make sounds in the same way other animals do. The sound comes from a place where the eagle's trachea (throat) divides to go to the lungs. The sound comes from a structure called a syrinx. Its call may be a mating call or a warning call.

An eagle's body temperature is higher than the 98.6 degrees F of a human. It is 106 degrees. Since eagles do not sweat, they must go into a cool place or lift their wings away from their bodies or pant to get cooled off. Because many bald eagles live in cold climates, they must have the means to tolerate the cold. Their skin is protected by feathers which are lined with down. The outside of their beaks has no blood supply so cannot feel cold. Their feet are cold resistant and consist mainly of tendons.

The hook on their beak is used for tearing flesh from their prey. Their talons dig into their prey and kill them.