Underneath the feathers, a bird looks like a plucked chicken. Note that it's knee is actually hidden up under its feathers and the joint you sometimes see below the body is actually its ankle! The wing feathers attach to the hand and forearm.

Studying bird anatomy will help you draw birds more accurately. Feathers grow from specific regions on the bird's body with bare skin between them. These feather groups define the shape and contours of a bird and the patterns on the feathers relate directly to the underlying feather group. This animation shifts between a drawing of a Song Sparrow,its shape without feather patterns, and a diagram emphasizing the feather groups.

The feather groups are under individual muscular control and can be fluffed up or moved together. Birds fluff themselves up when they are cold and smooth their feathers when they warm up. Birds also fluff their feathers a part of displays. Watch carefully as the bird's shape changes as different feather groups are puffed out or relaxed.