Birds are vertebrates. They belong to the group of animals that have .
Like mammals, birds are -blooded.
A bird's body is covered with .
Woodpeckers have a pointed so that they can cut into trees and look for insects.
Birds have a very good sense of .
Penguins, ducks and geese belong to the group of birds.
Birds of eat the flesh of other animals.
The smallest bird is the
An Arctic can travel thousands of kilometers between breeding grounds.
The fastest running bird is the
In the course of time the wings of penguins have turned into .
In America there are only a few thousand bald left.