How does the hoatzin digest leaves?
The hoatzin is an unusual leaf-eating bird of wet forests in the Amazon and Orinoco basins.
Anatomy, feeding and habitat
Leaves are fermented by microbes in the crop and enlarged foregut. The system is not inherited from ruminant mammals but performs a comparable function. The large digestive chamber limits space for flight muscles, so the hoatzin is not a powerful long-distance flier. Fermentation can also produce a distinctive odor. A bird's bill, feet, wings and feathers offer clues to feeding and movement, although one structure can serve several functions. Flight depends on muscles, body proportions and weather as well as wing size. Season, age and molt may change appearance.
Behavior, reproduction and conservation
Chicks have wing claws that help them grip branches; when threatened they may drop into water, swim and climb back. These claws are greatly reduced in adults. Riverside vegetation provides nesting and food, so wetland damage directly affects the life cycle. Breeding timing relates to food and climate, and nest success from one year is not generalized. Light pollution, glass collisions, habitat loss and invasive species affect birds differently. Conservation includes feeding, resting and migration sites as well as nests.