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Black-crowned Night-Heron (Nycticorax nycticorax)

2010; Linguagem: Inglês

10.2173/bna.bcnher.02

1061-5466

Roger L. Hothem, Brianne E. Brussee, William E. Davis,

Animal Ecology and Behavior Studies

The black-crowned night-heron is a stocky, medium sized, black, gray and white wading bird.In comparison to other egrets and herons, the legs and neck of the night-heron are relatively short.Adult blackcrowned night-herons are distinct, with a black back and crown, gray hind neck and wings, and a white cheek and underparts.In breeding plumage, long white streamers extend from the crown down the back beyond the neck.The bill, which is black in adults, is thick, stout, and spear-shaped.The legs are greenish-yellow, but turn pink in breeding adults.Eye color changes from yellow in juveniles to red in adults.In flight, the toes extend beyond the tail.The call of the black-crowned night-heron is a loud, guttural woc!Although their body shape is similar, the plumage of juvenile black-crowned night-herons is quite different from that of adults.Juveniles are buff below with brown streaking and brown above with buff-white markings.The bill is grayish-yellow at the base with a dark tip.Adult plumage is acquired by two years of age.Black-crowned night-herons are similar in appearance to yellow-crowned nightherons (Nyctanassa violacea), especially in juvenile plumage.The yellow-crowned has a longer neck and more slender body than the stocky black-crowned night-heron.The adult yellow-crowned lacks the black back of the black-crowned and has a black head with a white cap and cheek patch.The juvenile yellow-crowned is darker brown above, with smaller buffy markings on the back and more brown below.The bill of the yellowcrowned is shorter, yet heavier, than that of the black-crowned, and does not have a light base on juveniles.In flight, the legs and feet extend beyond the tail in the yellowcrowned, while only the toes extend beyond the tail in the black-crowned night-heron.Juvenile black-crowned night-herons may also be confused with American bitterns (Botaurus lentiginosus).In flight, the night heron shows a solid brown upperwing, while that of the bittern is two-toned.The bill of the bittern is also longer, thinner, and lighter colored.The back of the bittern is chestnut brown and lacks buffy spotting.