American Coot is the only species of coot that occurs in North and Central America, in the Caribbean, and in northernmost South America. American Coot is blackish gray, darker on the head and neck, with a white bill. The bill extends back onto the forecrown as a "shield". In most of its range, the shield is white with a reddish brown patch at the apex. The shield is entirely white in some individuals, however, and the white shield predominates in parts of the Caribbean; these white-shielded tropical coots formerly were considered to be a separate species, "Caribbean Coot" (Fulica caribaea). Like most species of coot, American Coot can be very pugnacious both in the breeding season as well as in wintering flocks. It appears that certain individuals in the wintering flock are consistently the most aggressive. American Coot is much more common in western North America than it is in the east, and in winter it forms dense wintering groups, even in small ponds such as those in golf courses. During the breeding season American Coot occupies marshes with a mix of open water as well as dense emergent vegetation. The nest is placed in a vegetated area, even a rather small one, and foraging takes place in the more open areas of the marsh. American Coot is an adept diver and feeds on aquatic matter from the marsh bottom. American Coot is migratory, with northernmost populations retreating considerably while southern ones are reinforced by birds from the north. All migration takes place at night, American Coot seldom is seen in flight; in flight, it shows a bold whitish trailing edge on the secondaries.