Black-crowned night-heron adult underparts and head are gray-white, the back and crown are black, and the wings gray. Bill is heavy and black; legs are yellow. Eyes red. Whitish head plumes develop in breeding season. Immatures are brown streaked and spotted with white; they are more streaked and spotted than immature yellow-crowned night-herons, and the bill is slimmer, with a light-colored base. Legs are shorter than the yellow-crowned’s, with only the feet extending beyond the tail in flight. A deep guttural quoc or qwoock can be heard as they move about in the dark and twilight; it is lower-pitched than the yellow-crowned’s call.
Similar species: Adult yellow-crowned night-herons have a creamy-white cheek patch and crown; back with dark markings. Immatures of that species are less streaked and spotted, have heavier, solid-dark bills, and longer legs (in flight, the feet plus the lower legs can be seen beyond the tail). American bitterns in flight have slimmer, pointier wings whose upper surfaces have a chocolate brown outer half and lighter brown inner half. In night-herons, the upper wings look solid dark brown.
Length: 25 inches (tip of bill to tip of tail).
Habitat and Conservation
A wetland bird, foraging in marshy areas and nesting in trees or cattails near water. In Missouri, it occurs in breeding colonies in summer, mainly in the Mississippi Lowlands. It forages in marshes and along edges of flooded fields, ponds, and lakes. Uncommon migrants, they are also observed in late summer after the breeding season after they disperse from nesting colonies.
Like other herons, this species hunts a wide variety of animal foods, ranging from insects, clams, and worms to fish, amphibians, reptiles, rodents, and other birds. They sometimes eat dead animals, human garbage, and even some plants. Although active in the daytime and not technically nocturnal, night-herons get their name from their habit of foraging primarily in the evening. Apparently, the behavior of feeding at night is an adaptation preventing competition with other types of herons.
Uncommon transient and summer visitor. As summer resident (breeder), locally uncommon in southeast Missouri, casual elsewhere. As winter visitor, casual in southern Missouri. It is not easy to determine numbers and population trends, but they may be declining. If they are, the causes undoubtedly include loss of habitat (draining and development of wetlands) and chemical pollutants, to which they are sensitive.
Nests are in trees or cattails, usually on islands or other places inaccessible to ground predators. The platform nests are about a foot high and at least a foot wide, made of sticks and twigs. These social birds nest in colonies, reusing the same site year after year for decades. A clutch contains 3–5 eggs. Incubation lasts about 25 days. Upon hatching, the young are fairly helpless. They stay in the nest about a month and learn to fly about two weeks later. There is one brood a year.
Herons and other wetland animals are not often seen by people, since few of us spend much time in marshes. But it’s a fact that we need clean water to live, and that healthy wetlands are needed for clean water. All the plants and animals of wetlands contribute to the health of those habitats.
Predators help keep in balance the populations of the animals they eat. As top predators, adult night-herons are rarely preyed upon. But snakes, raccoons, and other animals will eat their eggs and young, if they can get to them. Nesting in colonies and in remote areas helps prevent predation.