Blue-Winged Ducks of the World Seven "blue-winged ducks" occur worldwide, with at least one on every continent except Antarctica. This group includes three small-bodied teal (blue-winged teal, cinnamon teal and garganey) and four shovelers (northern shoveler, cape shoveler, red shoveler and Australasian shoveler).
The northern shoveler is the most widely distributed of these ducks, occurring throughout North America, Europe and Asia. Its southern relative, the cape shoveler, is the most restricted, occurring only in South Africa. The Australasian shoveler, as you can probably guess, is found in Australia and New Zealand. And if you are ever lucky enough to see a male Australasian shoveler in breeding plumage, with its spoon-shaped bill, iridescent green and slate blue head, rusty flanks and white facial crescent, there will be no denying its relationship to our blue-winged teal and northern shoveler. The red shoveler is a fairly common duck in South America, where it joins the cinnamon teal as the only two blue-winged ducks found on that continent.
Interestingly, despite its small population size and restricted range in North America, the cinnamon teal is the only native dabbling duck that breeds in temperate regions of both the northern and southern hemispheres. Blue-winged teal are largely restricted to North America, although individuals regularly venture into South America. Its Old World counterpart, the garganey, breeds in northern Europe and Asia and makes epic long-distance migrations to its wintering grounds in tropical Africa and Asia.
The blue-winged ducks share several interesting behaviors related to migration
, foraging, breeding and courtship that set them apart from other ducks. For example, social foraging, which is rare among other waterfowl, is common among these species. Northern shovelers, whose diet largely consists of tiny aquatic invertebrates, often feed by huddling with their heads down and swimming in a tight circle as they churn the water with their feet. This form of social foraging, known as "whirling," concentrates aquatic insects and plankton on which the birds feed.
Another hallmark of the blue-winged ducks is aggressive territorial behavior during the breeding season. Most ducks have a relaxed form of territoriality, in which they defend their mate or some portion of a wetland from intruding members of their own species, especially females. But the blue-winged ducks are aggressive toward both males and females of their own kind and blue-winged and cinnamon teal are aggressive toward one another on the breeding grounds. This unique behavior may be a consequence of the very close relatedness of these species.
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