Like humans, birds have both forelimbs and hindlimbs. Unlike us, however, their forelimbs have evolved into wings, leaving their legs and feet to perform a remarkable variety of tasks. Birds use their legs and feet for scratching and digging, clinging to surfaces, walking, preening, holding prey, swimming, steering during flight, building nests, and much more. Let’s take a closer look at the fascinating anatomy of bird legs.

Leg or Foot?

Much of a bird’s leg is hidden beneath its flank feathers. The part we usually see—and think of as the leg—is actually much of the bird’s foot.

What may appear to be a backward-bending knee is actually the bird’s ankle. Everything below that joint is part of the foot structure, including the long section that many people mistakenly identify as the lower leg.

A Familiar Skeletal Structure

Birds share the same basic skeletal blueprint as humans, but many of the bones in their legs and feet are fused together.

For example, humans have separate ankle and foot bones called tarsals and metatarsals. In birds, some of these bones are fused into a single bone known as the tarsometatarsus. Other ankle bones are fused with the shin bone (tibia) to form the tibiotarsus.

These fused bones provide strength while reducing weight—an important adaptation for flight.

Walking on Tiptoes

Most birds walk on their toes, making them what scientists call digitigrade animals.

In a sense, birds are always walking on tiptoes. If humans moved in the same way, our heels would remain elevated off the ground while we walked.

Not all birds fit this pattern. The Common Loon, for example, places its entire foot on the ground when walking. Its feet are specially adapted for powerful swimming rather than efficient movement on land.

Legs and Flight

Birds position their legs differently during flight depending on their size and body shape.

Many perching birds draw their legs tightly against their bodies. Birds with longer legs, such as herons and egrets, typically extend them behind the body and tuck them beneath the tail. Only a few species regularly fly with their legs dangling beneath them. One example is the American Woodcock.

Leg Fun Facts

Standing on One Leg
Many long-legged birds stand on one leg while resting in water. This behavior helps reduce heat loss by keeping one leg tucked into their warm feathers.

Built for Clinging
Swifts have extremely short legs and spend very little time on the ground. Their feet are specially adapted for clinging to vertical surfaces such as cliffs, chimneys, and walls.