You may be thinking of a vulture, which only has skin on its head. The bald eagle, however, has white feathers on its head.
a bald eagle
One bird described as "bald" because of the white feathers on its head is the American Bald Eagle, a protected species that is the official bird of the nation as a whole.
The bald eagle, because it's head is bald.
eagles
The answer you are looking for is probably a "bald eagle", however the bald eagle does not have a bald head. [See related link for a picture of a "bald" eagle.
vulture
vultures.
The Bald Eagle
Bald Eagle.
vulture
vulture
Bald Eagle.