Harteman Wildfowl, presented by Jan Harteman

American black duck

Anas rubripes

Amerikaanse zwarte eend / Dunkelente / Canard noitrâtre américain

 

The American black duck is a large dabbling duck. American black ducks are similar to mallards in size, and resemble the female mallard in coloration, although the black duck's plumage is darker. It is native to eastern North America and has shown reduction in numbers and increasing hybridization with the more common mallard as that species has spread with man-made habitat changes.

 

Their breeding habitat is alkaline marshes, acid bogs, lakes, ponds, rivers, marshes, brackish marshes, and the margins of estuaries and other aquatic environments in northern Saskatchewan,Manitoba, across Ontario and Quebec as well as the Atlantic Canadian Provinces, including theGreat Lakes, and the Adirondacks in the United States. Female black ducks lay an average of 9 eggs.

Black ducks interbreed regularly and extensively with mallard ducks, to which they are closely related. Some authorities even consider the black duck to be a subspecies of the mallard, not a separate species at all. Mank et al. (2004) argue that this is in error as the extent of hybridization alone is not a valid means to delimitate Anas species.

 

This species is partially migratory and many winter in the east-central United States, especially coastal areas; some remain year-round in the Great Lakes region. These birdsfeed by dabbling in shallow water, and grazing on land. They mainly eat plants, but also some molluscs and aquatic insects. The eggs are a greenish buff color. They lay from 6–14 eggs, and hatch in an average of 30 days.

 

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern (IUCN, 2012).

 

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Above: adult pair American black ducks, female in front

 

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Above: adult male American black duck

 

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Above: adult female American black duck

 

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Above: adult male American black duck

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