Oscar Dewhurst / Hoatzin (Ophisthocomus hoazin) perched on wooden bar overlooking oxbow lake. Manu National Park, Madre de Dios, Peru. September

Staffan Widstrand / Hoatzin birds (Opisthocomus hoazin) perched on branch, Napo wildlife lodge, Amazonas, Ecuador, South America, April.

Konrad Wothe / Hoatzins (Opisthocomus hoazin) perched in rainforest, Tambopata Reserve, Peru, South America.

Oscar Dewhurst / Hoatzin (Ophisthocomus hoazin) perched on fallen tree branch. Manu National Park, Madre de Dios, Peru. September

Oscar Dewhurst / Hoatzin (Ophisthocomus hoazin) perched on wooden bar overlooking oxbow lake. Manu National Park, Madre de Dios, Peru. September

Bernard Castelein / Hoatzin, (Opisthocomus hoazin), perched by water, Municipal protected area of Pampas del Yacuma, Bolivia

Bernard Castelein / Hoatzin ( Opisthocomus hoazin) at water's edge Pampas del Yacuma Protected Area, Bolivia

Bernard Castelein / Hoatzin ( Opisthocomus hoazin) group , Pampas del Yacuma Protected Area, Bolivia

Bernard Castelein / Hoatzin (Opisthocomus hoazin), climing on a vine, Madidi NP, Bolivia

Alex Hyde / Hoatzin (Opisthocomus hoazin) Cocha Salvador ox-bow lake. Manu Biosphere Reserve, lowland Amazon rainforest, Peru.

Alex Hyde / Two Hoatzin (Opisthocomus hoazin) on Cocha Salvador ox-bow lake. Manu Biosphere Reserve, lowland Amazon rainforest, Peru.

Nick Garbutt / Hoatzin (Opisthocomus hoazin), pair on floating log in Cocha Salvador ox-bow lake. Manu Biosphere Reserve, Peru.