Reclusive, rarely seen diving duck of tropical lowlands. Feeds mainly at night and spends much of the day sleeping quietly in marshy vegetation, often in small ponds and even in roadside ditches. Rarely seen in flight, but can spring into the air rather than run along the water. Male in breeding plumage has black face mask, bright blue bill, and dark rusty body. Female-plumaged birds are seen much more often: note buffy face with double dark face stripes.