33 Waders Wading birds have long toes to prevent them sinking into soft mud. Lily-trotter Jacanas can walk over floating plants on their long, thin toes. Flanged feet The coot has double flanges of scaly skin that extend from the toe bones. During swimming, the flanges open out as the foot moves backwards, and closes as it moves forwards. Canada goose foot Moorhen foot Elongated, widely spread toes Scaly flange aids swimming Coot foot Coot Webbed feet Ducks, geese, swans, gulls, and many seabirds have webbed feet for efficient swimming. Petrels can almost “walk” on water by pattering with their webbed feet and flapping their wings, while waterfowl use their feet as waterbrakes when landing. Webbed toes for swimming Legs for perching Perching birds have a special mechanism to prevent them falling off perches. When a perching bird lands on a branch, its weight makes its leg tendons tighten and clamp its toes tightly shut. To take off, the bird contracts its toe muscles, the foot springs open, and it can then fly away. Nuthatch landing Perching bird’s leg Toes clamp to perch when bird rests its weight on the foot Walking tracks Instead of hopping, large birds transfer their weight from foot to foot by walking. Hopping tracks Small birds, particularly those that live in woodland, hop on the ground. Bird tracks Birds move on the ground in one of two ways. Many smaller birds hop, as they can easily lift their body weight by flexing their feet. Larger birds cannot hop, and so walk instead. Tracks in mud Bird tracks are best seen in wet mud and fresh snow. Goose tracks Finch tracks Thigh bone Ankle joint