Superficially resembling night-herons in the genus Nycticorax, the Boat-billed Heron differs in its extremely wide, flat bill whose maxilla looks like the upturned keel of a boat, giving this species its common name. The only member of the genus Cochlearius, the Boat-billed Heron used to be in its own family before being grouped back into the family Ardeidae with the other herons. A crepuscular species, it uses its unique bill to hunt amphibians, small fish, crustaceans, insects, and small vertebrates, while wading through shallow water. The courtship display of this species is quite ritualized and includes carefully coordinated bill-touching and false fighting. It has been known to nest individually or in mixed species colonies of other herons and ibises. Unlike other species of herons, the Boat-billed Heron is very aggressive when defending its nest and young against potential predators, scaring away other species of birds, and vocalizing loudly, even lunging, at approaching humans.