They are medium-sized herons in the genera Nycticorax,
Nyctanassa and Gorsachius. The genus name Nycticorax derives from the Greek for
“night raven” and refers to the largely nocturnal feeding habits of this group
of birds, and the croaking crow-like call of the best known species, the
Black-crowned Night Heron. In Europe, Night Heron is often used to refer to the
Black-crowned Night Heron, since it is the only member of the genus in that
continent. Adults are short-necked, short-legged and stout herons with a
primarily brown or grey plumage, and, in most, a black crown. Young birds are
brown, flecked with white.
At least some of the extinct Mascarenes taxa appear to have
retained this juvenile plumage in adult birds. Night herons nest alone or in
colonies on platforms of sticks in a group of trees, or on the ground in
protected locations such as islands or reedbeds. 3-8 eggs are laid. Night
herons stand still at the water's edge, and wait to ambush prey, mainly at
night. They primarily eat small fish, crustaceans, frogs, aquatic insects, and
small mammals. During the day they rest in trees or bushes. There are seven
extant species. The genus Nycticorax has suffered more than any other
ciconiiform genus from extinction, mainly because of their capability to
colonize small, predator-free oceanic islands, and a tendency to evolve towards
flightlessness.
