boat-billed heron or boatbill, a tropical New World heron, Chochlearius chochlearius. With shorter legs and a squatter appearance than most herons, this bird is remarkable chiefly for its broad bill, which is shaped like an overturned boat. Its coloring is dull brown, gray, and black and is similar in both the male and female. It is a nocturnal, shallow-water feeder, living on a diet of fishes and insects; it roosts and nests in trees. The boat-billed heron inhabits mangrove swamps from Mexico to S Brazil. It is classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Ciconiiformes, family Ardeidae.