The Turkey Vulture is often seen soaring just above the trees in search of carrion, sometimes in large circling groups. In flight, it holds its wings in a slight dihedral (V-shape) and rocks slightly from side to side. Seen from below, the front of the wings are dark, and the flight feathers are gray. It has a hairless red head and hooked white bill, both specially evolved for its diet of mostly carrion. It searches by sight and smell, while the only other eastern vulture, the more aggressive Black Vulture, hunts by vision alone. The Black Vulture is completely black above, including its head. In flight, it has a much shorter tail, white outer primaries, and flaps its wings more than the Turkey Vulture. Both often roost communally at night. Turkey Vultures migrate, but are found year-round in much of their range, including Maryland and California.