Hair is another feature separating mammals from other animals. Hair comes in many forms, from the barbed quills of porcupines to the soft fur of a lemur. Birds All birds have feathers, making them different from all other animals. Birds have several types of feathers, from stiff contour feathers, which cover the wings and body, to fluffy down, which helps keep birds warm. Special contour feathers on the wings, called flight feathers, help to lift and maneuver birds in the air.
All birds have wings - even ostriches and other flightless birds.
The type of flying a bird does depends on the size and shape of its wings. Soaring birds, such as eagles and vultures, have long and broad wings. Forest birds such as song birds have short broad wings for flying in thick vegetation. And fast fliers like falcons and swallows, have long pointed wings. Other characteristics of birds include hollow or partially hollow bones with very thin braces for extra strength, keen eyesight with the ability to focus each eye independently, a keen sense of hearing, and a beak.