The black-bellied whistling duck is a species of waterfowl that is distinctly different in behavior and appearance than most other types of duck. It has been described by one ornithologist as "un-duck-like" due to certain behaviors, such as monogamous pair-bonding, that more closely resemble that of swans or geese. This bird is also known by its scientific name Dendrocygna autumnalus. In some areas, it is colloquially called the black-bellied tree duck or whistling duck.
Female and male specimens of the black-bellied whistling duck are difficult to tell apart, as both sexes have pink legs, a patch of white on the wing, and a red bill. Their heads are gray, with a black tail and belly. Rich brown plumage covers the neck, head, and body, and the eyes feature a noticeable ring of white. The wide patch of white on the wings is more evident when the bird is flying than when it is at rest. This duck has a neck and legs that are unusually long compared to most ducks.
The black-bellied whistling duck can be found in breeding areas year-round in south Texas, as well as seasonally in parts of Arizona, Louisiana, and South America. This bird has also been spotted in parts of South Carolina, Florida, Georgia, and Arkansas. Only the most northern populations of black-bellied whistling duck are known to migrate in winter. The species is found in elevations ranging from sea level up to more than 4,900 feet (1.5 km).
These whistling ducks are approximately 19-21 inches (48-53 cm) in length and weigh up to 36 ounces (1,020 g), with a wingspan of about 37 inches (93.9 cm). The black-bellied whistling duck typically lives up to eight years in the wild. Its whistling vocalizations are variously described as "pe-che-che-ne," "waa-choo," or "pi-yih-pyi-pyi."
This unusual waterfowl lives near shallow water sources such as lakes, marshes, and ponds. The black-bellied whistling duck prefers water locations lined with woods because of its habit of perching or nesting in trees. It is sometimes also seen on grassy swaths of land, such as golf courses.
These omnivorous birds eat seeds, grasses, insects, and small invertebrates. They generally feed at night, sometimes in large flocks of hundreds at a time. These ducks also eat rice or corn crops, if available. In some Spanish-speaking areas, the black-bellied whistling duck might alternately be known as pato maizal or "cornfield duck" because of its preference for dining on corn crops.