Nycticorax nycticorax
(Black-crowned Night-heron)


Order: Ciconiiformes
Order Description: Bitterns, Herons, Egrets,and Ibises
Family: Ardeidae
Family Description: Herons, Bitterns, and Egrets

Physical Description:
Size 23-28" (58-71 cm). A medium sized heron with stocky build and thick, black, slightly down-turned bill. Glossy black-green crown, gray wings and, underparts white. Three large white plumesClick word for definition on the back of the neck. Short neck. Usually stands hunched, inactive. Immatures are mottled brown with buffClick word for definition spots or streaks.

Similar Species- Immature Black-Crowned Night-Herons can resemble American Bitterns. The Bittern has a black neck stripe and black primaries.

Song:
A flat, barking Quock!

Distribution:
Breeds from Washington and southern Idaho, east through parts of Canada and Great Lakes to Nova Scotia, and south to southern South America. Winters from Oregon, Utah, lower Ohio Valley, and New England, south to South America.

Habitat:
Found in brackishClick word for definition, saltwater, or freshwater situations in marshes, swamps, and wooded streams, and on shores of lakes, ponds, and lagoons.

Diet:
Feeds opportunistically on fishes, amphibians, and invertebrates; may also eat small mammals and young birds.

Ecology:
NocturnalClick word for definition/crepuscularClick word for definition, but may sometimes feed by day. Builds nest in trees or bushes. In Idaho, prefers to nest in trees and bushes such as alders, cottonwood, chokecherry, and willows. Nests in small to large colonies. Forages in shallow water for food; may also forage on land. In Idaho, predators include various gulls, Black-billed Magpies, and American Crows. Reproduction has been depressed by pesticide contamination. Some Idaho birds winter in Mexico.

Reproduction:
clutchClick word for definition size varies from 3-5 eggs in northern range, 2-4 eggs in south (southeastern Idaho study reported 3.6 average clutch size). Both sexes incubateClick word for definition eggs; incubation apparently lasts 24-26 days. Young fly at about 42 days, and usually breed at 2-3 yr.

Conservation:
Element Code: ABNGA11010
Status: Protected nongame species
Global Rank: G5
State Rank: S3
National Rank: N5B,N5N

Important State References:
Findholt, S. and C.H. Trost. 1985. Organochlorine pollutants, eggshell thickness, and reproductive success of Black-crowned Hight-Herons in Idaho, 1979. Colonial Waterbirds 8:32-41.


Photo by George Jameson, ©2002
Design by Ean Harker©1999, 2000.
Written by Jason Karl, 2000.