- The black-bellied whistling-duck is a distinctive fowl with long pink legs and a long neck. Its face is gray and its bill is red. White coloring is located in a ring around the eye and on the wings which is visible during flight. Audubon describes the back, neck and cap as a rich chestnut brown. As its name indicates its belly is black. An adult weighs between 23 and 36 oz. and is 18.5 to 20.1 inches long.
- The year-round range of the species starts in southeast Texas and passes through Mexico and goes down through Central America and South America to northern Argentina. Besides its year-round presence in Texas, the black-bellied whistling-duck can be found seasonally in southern Arizona and Louisiana's Gulf Coast. Occasionally it will breed in Arkansas, South Carolina and Florida. Within the range, the ducks prefer bodies of water like freshwater ponds or lakes with trees for perching. These habitats also provide the ducks with an environment to satisfy their eating habits.
- Black-bellied whistling-ducks utilize their aquatic abilities as part of their eating habits. They wade into shallow water to eat underwater vegetation. Their diet also includes plant vegetation that is not submerged along with insects located around the ponds and lakes of their habitat.
- Black-bellied whistling-ducks tend to feed at night, according to Audubon, although they are not strictly a nocturnal animal and will feed at any time of the day.
- In Mexico, the black-bellied whistling-duck carries the name "pato maizal" which translates as cornfield duck. This refers to the practice of gleaning harvested fields for the leftover corn. Reports indicate that the ducks possess the ability to open husks of corn and eat the kernels.