Black Terns nest in New York State in only a few marshes along the south and east shores of Lake Ontario, at the southern edge of their breeding range. They are more abundant in the upper Midwest, but the habitat managed here suits their needs and gives visitors a chance to see an uncommon bird. They build nests on mats of floating vegetation or mud mounds barely above water level, and several nests may be built in the same area. Adult Black Terns have a wingspan of 24 inches and a length of 9.75 inches. Their metallic kek or kyip call can be heard while they are in flight, and they can be seen flying low over the marsh, dipping and banking from side to side as they search for insects and small fish. Black Terns mob intruders that come too close to their nests, and muskrat huts and push-ups make good nesting platforms. In breeding plumage from March through August, adults have gray wings and tail, a white undertail, dark red legs, and a black head and breast. In non-breeding plumage from August through February, adults have a black cap, cool gray wings and back, a white face and body, and red legs. Juveniles from July through November have a dark gray cap, warm gray wings and back, a white body, and orange legs.