Parasitic JaegerStercorarius parasiticus
21" (53 cm). A fast-flying, gull-like seabird. Typical adults are brown above, white or light dusky below, with an incomplete gray-brown band across the breast; a dark, almost black, crown; and short (up to 3-4") pointed central tail feathers. Dark-phase birds are uniform dusky brown with a darker cap; intermediates between the two color phases occur. Often seen harrying gulls and terns.