Black-bellied Whistling Ducks nest in thickets or stands of mesquite, hackberry, willow, live oak, and other trees. They forage in fields, lawns, and shallow, freshwater ponds that often contain water hyacinth, water lilies, and cattails. In the tropics, they also use mangroves, rivers, and lagoons.Back to top
Black-bellied Whistling-Ducks eat mainly plants, including smartweed, grasses, swamp timothy, amaranth, sedges, bindweed, and nightshade. They also eat many agricultural crops including sorghum, millet, corn, rice, and wheat. They eat a smaller amount of aquatic animals such as snails, insects, and spiders. They typically forage at night, leaving roosts at sunset to fly to foraging areas. They feed in fields or by dabbling in shallow ponds.Back to top
Usually nests in tree hollows where a limb has broken or the trunk has rotted away. They also use nest boxes and sometimes nest on the ground. Both sexes help select the nest site.
Whether nesting in natural cavities or nest boxes, Black-bellied Whistling-Ducks typically don’t build a nest; they lay their eggs directly on whatever debris has collected there. Cavity openings range from 5–12 inches across. When nesting on the ground, they make a scrape or a shallow bowl of grasses, with thick vegetation overhead, such as willow, mesquite, or cactus.
|Clutch Size:||9-18 eggs|
|Number of Broods:||1-2 broods|
|Egg Length:||1.8-2.4 in (4.5-6.2 cm)|
|Egg Width:||1.2-1.6 in (3-4.2 cm)|
|Incubation Period:||25-30 days|
|Nestling Period:||10-13 days|
|Condition at Hatching:||Almost independent at hatching. Covered with black-and-yellow down, eyes open.|
Black-bellied Whistling-Ducks have long legs and spend more time than other ducks walking on land or perching in trees. You may see them perched on fences, telephone lines, or in Spanish moss. They are gregarious year-round, forming flocks of up to 1,000 birds. They form lifelong pair bonds and breed in their first year of life. Males spar by chasing or nipping at each other, or with a threat display that involves stretching their neck forward and opening their bill. Pairs form in winter; courtship includes birds stretching their necks out horizontally, dipping their bill, and flicking water over the back. Females often lay eggs in the nests of other whistling-ducks—a behavior known as egg-dumping. Individuals are attracted to areas where corn and rice are grown and can cause damage to crops. Nest predators include raccoons, rat snakes, and bull snakes; ducklings may be killed by fire ants, bass, catfish, and gar. Great Horned Owls sometimes take adults.Back to top
Black-bellied Whistling-Ducks have steadily expanded their range in the southern U.S. and their numbers have increased by approximately 6% per year from 1966–2019, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 1 million and rates them 8 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Although it’s legal to hunt whistling-ducks in season, they are only rarely targeted by hunters. Like all aquatic species, Black-bellied Whistling-Ducks are vulnerable to poor water quality. In the 1980s, birds in Mexico were reported with high levels of DDT, dieldrin, and other persistent organic compounds. Degradation or clearing of wetlands can reduce habitat availability; however, in general, Black-bellied Whistling-Ducks seem to be doing well around human development.Back to top
Bolen, E. G. (1967a). Nesting boxes for Black-bellied Tree Ducks. Journal of Wildlife Management 31:68-73.
Ehrlich, P. R., D. S. Dobkin, and D. Wheye (1988). The Birder's Handbook. A Field Guide to the Natural History of North American Birds, Including All Species That Regularly Breed North of Mexico. Simon and Schuster Inc., New York, NY, USA.
James, J. Dale and Jonathan E. Thompson. (2001). Black-bellied Whistling-Duck (Dendrocygna autumnalis), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
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Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
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