Black-bellied Whistling Duck

The Black-bellied Whistling-duck is 19-21 in (48–53 cm) long. It has a long red bill, long head and longish legs, pale grey head and mostly grey-brown plumage. The belly and tail are black, and the body plumage, back of the neck and cap are a rich chestnut brown. The face and upper neck are grey, and they sport a thin but distinct white eye-ring. The extensive white in the wings is obvious in flight, less so on the ground; it is formed by the secondary remiges while the primaries are black; the wing-coverts are brown. Males and females look alike; juveniles are similar but have a grey bill and less contrasting belly.
Feeding often occurs nocturnally, but they can be encountered eating at any hour of the day. Black-bellied whistling-ducks ingest a wide variety of plant material, but also consume arthropods and aquatic invertebrates when available. They often feed on submerged vegetation by wading through shallow water. As its Mexican name implies, it is commonly seen gleaning recently-harvested fields for leftover seed and invertebrates brought up by the harvesters disturbing the soil.
The Black-bellied Whistling-duck is quite unique among ducks in their strong monogamous pair-bond. Its pairs often stay together for many years, a trait more often associated with geese and swans. Both parents share all tasks associated with the raising of young, from incubation to the rearing of ducklings.