[order] Anseriformes | [family] Anatidae | [latin] Oxyura jamaicensis | [UK] Ruddy Duck | [FR] Érismature rousse | [DE] Schwarzkopf-Ruderente | [ES] Pato Malvasia de Cara Blanca | [IT] Gobbo rugginoso americano | [NL] Rosse Stekelstaart

Rosse Stekelstaart determination

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The Ruddy Duck known for holding their spiky tails up in the air. They have large, flat bills, small wings, and feet set far back on the body. The male Ruddy Duck is cinnamon in color overall with a black head, large, white cheek-patch, and bright blue bill. The male in non-breeding plumage has a mottled gray body and gray bill. The markings on the head are similar to those of breeding plumage. The female is mottled gray overall with black on the top of her head and a dark, horizontal line that bisects her white cheek. Her bill is gray. The juvenile is similar to the female, but the black on its face is less pronounced.
Ruddy Ducks are often found in tight flocks. They forage by diving under water and straining mud through their bills to find food. Like many small-winged ducks, Ruddy Ducks must get a running start across the water to become airborne.

In winter, Ruddy Ducks inhabit shallow, protected, saltwater bays and estuaries along the coast or ice-free, inland lakes and ponds. Breeding habitat is freshwater marshes and ponds with marshy borders mixed with open water.

In Britain, escaped captive birds began breeding regularly Somerset 1960 and Stafford 1961; have now reached Scotland and Wales. As range has expanded, records in continental Europe have increased, with first observation 1965 in Sweden (now almost annual) and from 1970s-80s elsewhere. Recorded from Iceland (bred 1990, 1993, 1994), Ireland (breeding since 1973), France (bred Pas-de-Calais 1988), Belgium (first breeding record 1991), Netherlands (occasional breeding since 1977, uncertain whether population self-sustaining), Germany, Denmark, Norway, Finland, Switzerland, Spain females have bred with males White-headed Duck in Andalucía), Portugal (bred 1995), Italy, and since December 1992 in Morocco. Beyond west Palearctic, breeds from western North America south through West Indies and western South America to Tierra del Fuego.

Seeds and tubers from aquatic vegetation are a main staple of the Ruddy Duck's diet. Aquatic insect larvae are especially favored during the breeding season. Mollusks, crustaceans, and some small fish are also eaten.

Oxyura jamaicensis has a large, discontinuous range in the Americas, occurring in Canada, the USA, Mexico, the West Indies, and along the Andes from Colombia to Tierra del Fuego (Chile). An introduced population is established and spreading in the United Kingdom. It is partly migratory; North American breeders tend to depart from breeding grounds to winter further south or near the coast, whereas other populations are sedentary or make only short-distance movements. Freshwater swamps, lakes, pools, and marshes with emergent vegetation and open water are preferred breeding habitats, although outside the breeding season the species can also be found on larger lakes, brackish lagoons and estuaries (Carboneras 1992). Its estimated global Extent of Occurrence is 8,670,000 km2, and it has a large global population estimated to be 510,000 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. [conservation status from birdlife.org]

Pairs form after the birds have arrived on the breeding grounds. Nests are situated in dense marsh vegetation. The female builds a platform of grasses and cattails, lines it with down, and anchors it to emergent vegetation a few inches above the water. Many nests are concealed by vegetation pulled over the nest, which gives them a basket-shaped appearance. Sometimes the nest is built on top of an old muskrat house or bird's nest. The female lays 5 to 10 eggs (usually 8), and commonly lays eggs in the nests of other Ruddy Ducks or another species. The female incubates the eggs for 22 to 26 days. Within a day after hatching, the young leave the nest and can swim and dive well. They are tended by the female, but feed themselves. They first fly at 42 to 49 days.

British population mainly resident, but with regular, short, seasonal movements, deserting small breeding pools and meres to winter on some large reservoirs. Flocks develop September-December and disperse March-April. Increasing records in continental Europe (see Distribution) show that some birds wander further afield. Migratory in North America, withdrawing from breeding range (except in California) to winter in Pacific, Atlantic and Gulf coastal states of USA and south into Mexico, Belize, and Guatemala.