The Ruddy duck is a diving duck native to the Americas. The male duck has a reddish body coloration during the summer months, but the female has duller coloration with no hint of red all year round. In the colder months, the duck lives in coastal areas and marshlands, but prefers freshwater for the warmer portion of the year. Ruddy ducks are able to interbreed with other species of duck such as the white-headed duck, and so can be a cause for ecological concern in countries where it is not considered a native.
Unusually for a duck that likes diving for food, the Ruddy duck has a tail that appears stiff and that the duck tends to hold up out of the water. Instead of diving under, the duck can also slip under the water easily, which may be helpful as a way of unobtrusively avoiding predators. As the birds are most comfortable in the water, they appear uncoordinated on land. A male Ruddy duck is generally more colorful than the female, with a red body, blue-colored bill and black and white head. The female is mostly brownish gray with a gray bill.
Both North and South America are home to the Ruddy duck, which has the scientific name of Oxyura jamaicensis. For the breeding season in the summer, the ducks live in Canada, the United States or even Mexico, but in winter, they move to a range between the southern states of the U.S and El Salvador. The female of the species chooses her nesting place, which is generally close to water. She constructs the nest and makes a roof over it from old vegetation to make it invisible to potential predators. Typically, the female puts most of the effort into guarding the eggs and looking after the chicks.
Predators of the Ruddy duck include hawks and foxes, and the young are vulnerable to mink, raccoons and predatory birds like herons. People also hunt the ducks for meat, as the populations of the birds are, as of 2011, at healthy levels. The Ruddy ducks themselves eat a mixture of plant and animal food, which they find in water, such as crustaceans, larvae and seeds.
In the 1940s, Ruddy ducks found their way to Europe, perhaps as an ornamental import. Some European countries where the bird is regarded as a threat to native ecology actively attempt to eradicate the ducks. For example, a cull began in 2003 in the U.K. of the birds, as they were interbreeding with white-headed ducks in Spain and reducing the natural population of those birds, which were under threat.