Allied to the night herons is the boat-billed heron, Cochlearius cochlearius, which is also a nocturnal bird. The plumage is black, grey and white, but its most outstanding features are the broad bill, 3 inches long and 2 inches wide, and the long, wide black crest. The comparatively large eyes indicate its nocturnal habits. It ranges from the coastal lowlands of north-west and north-east Mexico south generally, to southern Brazil. It is a solitary feeder, preying on fish, crabs, mice, worms and other small animals.

During the breeding season it claps and rattles its bill to accompany the loud, harsh sound of its voice. The clutch comprises 2-4 white, brown speckled eggs. The boat-billed heron nests alone or in colonies with other herons. Some ornithologists place this species in a family of its own, Cochlearidae, others group it with the true herons.