Avise's Birds of the World

Hoatzin
Opisthocomus hoazin

Native Range: South America

Notes: a medium-sized long-tailed bird with a bluish face patch and spikey head feathers; its phylogenetic relationships have long puzzled ornithologists; some researchers think it is allied to cuckoos and their allies (Cuculiformes), whereas others think its relatives are pheasants and other gamebirds (Galliformes); inhabits tropical riparian habitats; a herbivore that feeds mainly on leaves, with digestion occurring in a large crop and foregut by microbial fermentation; young birds have two claws on each wing, which they use when climbing near the nest before fledging; when alarmed, the young may drop into the water and then climb back to the nest after the danger has passed; no sexual dimorphism; [This photograph was kindly provided by Steve Weller.]