Black bellied Tree Duck (Dendrocygna autumnalis)

[order] Anseriformes | [family] Anatidae | [latin] Dendrocygna autumnalis | [UK] Black-bellied Tree-Duck | [FR] Dendrocygne à ventre noir | [DE] Rotschnabel-Pfeifgans | [ES] Suirirí Piquirrojo | [IT] Dendrocigna beccorosso | [NL] Zwartbuikfluiteend

Physical charateristics

This species, as other tree ducks, is more closely related to geese and swans than to ducks. They have long neck and legs, and broad wings, and both sexes are similar. When in flight, Black-bellied tree-Duck has training wings and rounded wings, making it bigger than it is. Its red bill and legs, and the large white wing patch help to identify the species, and make the difference with the Fulvous Tree-Duck which lacks red bill and black belly.
Black-bellied Tree-Duck has tawny-brown to brown-cinnamon upperparts, turning black on rump and uppertail coverts. Upper wings show a broad white stripe, conspicuous in flight. Flight feathers are black. Underparts are paler. Lower neck and chest are tawny-brown. It has black belly and flanks. Undertail coverts are mottled black and white. Underwings are blackish. Head and upper neck are grey. Crown is dark brown. We can see a dark vertical hind neck stripe. Bill is bright pink-red, often yellowish at base. Eyes are dark brown, with conspicuous white eye ring. Legs and webbed feet are bright pinkish-red.
Both sexes are similar. Juvenile is paler, with grey bill, legs and feet. It has duller plumage than adults, with sooty-brown belly and flanks. It reaches its adult plumage at 8 months of age. Very young birds have very paler belly, with indistinct transversal bars.

Distribution

The Black-bellied Tree-Duck is natural to the Americas. Its distribution to the north includes southern United States (in the states of Texas, Arizona and Louisiana) and northern Mexico (state of Sonora on the Pacific side), although it is usual to see it further north than these limits. Continues its distribution south on both sides of Mexico thru Central America. Some make it to the Antilles in the Caribbean, being considered occasional in Puerto Rico.
In South America this species is native to Colombia, Venezuela, the Amazon Basin, southern Brazil, Paraguay and northern Argentina. West of the Andes it goes as far south as Peru. It is documented in Los Lagos, Chile.
A population descendent of escaped captive birds established in the 1960’s in the state of Florida, United States. In 1931 it was introduced to Cuba in the Zapata Swamp, earlier it had been introduced in Pinar del Rio. Still found in Cuba, although the ones seen could proceed from other places. Also introduce to Jamaica unsuccessfully, although it is seen there in winter and spring.

No sound impression of Black-bellied Tree-Duck

Habitat

Shows preference for rice and corn fields, pastures where other grains are cultivated. It is found in fresh water lakes, with and without aquatic vegetation, with shallow shores. Also in places where there are trees, sometimes resting on the branches.

Foraging habits

The basic diet is made up of grains: corn, rice and other crops. It is complemented with insects and crustaceans.

copyright J. del Hoyo

Breeding habits

The pair bond appears to be strong, perhaps for life. Breeding is once a year. In North America it starts at the beginning of summer, June and July, but it varies according to location. Fidelity for the nesting site is strong, many nests in the same place as the previous year.
Normally nesting is in a hole in a tree, but the nest could be on the ground. The nesting tree can be growing in the water or as far as a kilometer away from the nearest water deposit. Many pairs nesting in holes do not add any material to the location, the female lays the eggs on the bottom of the hole. Of those nesting on the ground some just deposit the eggs on the ground, while others build a cup-shaped nest with grass. Down is not added to the nest.
The clutch is eight to eighteen eggs. Once laying stars an egg is deposited every day. Some females lay eggs in the nest of others, some even on other ducks and even gulls nests. Some clutches are suspected to be where females lay because they have to, but the clutch itself is not incubated nor taken care of. One of these excess clutches was recorded to have 101 eggs. If the clutch is lost, it is possible that the pair may try again.
Incubation takes from 26 to 31 days and it is done by both parents. When the chicks hatch they are yellow with dark marks. Normally next day after hatching they drop from the hole in the tree, which could be as high as three meters, landing on the ground or water. They stay with the parents for the next six months. At two months they are able to fly, at eight moths they change to adult plumage and at one year of age they can start breeding.

Conservation

This species has a large range, with an estimated global Extent of Occurrence of 9,300,000 km². It has a large global population estimated to be 1,100,000-2,000,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. (source Birdlife.org)

Migration

This Tree-duck lives in tropical zones. Most of the populations are sedentary, although they move according to food scarcity. Those at the limits of the distribution are migratory, but it is suspected that the wintering grounds are not too far from the nesting areas. The ones nesting in North America in southern United States and northern Mexico winter in southern Mexico.