Ruddy Duck, Oxyura jamaicensis

Ruddy Duck, Oxyura jamaicensis, Female. Photograph taken in the San José Estuary, San José Estuary, Baja California Sur, February 2016. Photograph courtesy of Carol Snow, Del Mar, California.

Ruddy Duck, Oxyura jamaicensis, Breeding Male, Juvenile Female and Female with Juvenile. Birds photographed in the greater Mexico City area, March 2021. Photographs and identification courtesy of Marina Sutormina, Stockholm, Sweden.

The Ruddy Duck, Oxyura jamaicensis, is a diving duck and a member of the Anatidae Family of Duck, Geese and Waterfowl, which has one hundred seventy-four members placed in fifty-three genera, and one of six global species of the Oxyura Genus. Thye are known in Mexico as malvasía canela.

The Ruddy Duck is small and stocky in stature. The sexes are slightly dimorphic and strongly dichormatic. The males are slightly larger than the females. The males are strongly seasonally dichromatic, but the females are not. The males have a bright, sky-blue bill, white cheeks, a glossy black cap and nape, a bright reddish-chestnut upper body, a silvery-white belly, and a gray back. Their tail is dark brown, their wings are blackish brown, and their underwing converts are whitish. They have a thick neck and fan shaped tail composed of stiff, pointed feathers. The females have a dark distinct stripe from the gape to the ear coverts and their body has more speckled with light and dark bars and their bills are slaty. Their iris is reddish brown in males and warm brown in females; their legs and feet are slaty gray.

The Ruddy Duck is found in a variety of habitats, with the majority found on large freshwater permanent wetlands, lakes, and reservoirs and in fresh to brackish coastal bays, marshes, and tidal estuaries. They are highly adapted for their aquatic lifestyle with their feet set far back on the body which are some of the largest feet relative to body size of all ducks. On land they are immobile having a great deal of difficulty in walking. They require a long run across water to gain flight and generally only fly at dawn, dusk and at night. Their diet consists primarily of aquatic insects, crustaceans, zooplankton, and other invertebrates, and occasionally small amounts of aquatic vegetation and seeds. They spend almost all their life on water rarely moving to land to rest or preen. Unlike most waterfowl they form pairs on the breeding grounds. The males perform a unique, comical, courtship display and establish seasonally monogamous pair bonds, but some males are polygynous. The females lay large, rough white eggs in nests over water that are the largest eggs relative to body weight of all waterfowl. They have lifespans of up to fourteen years.

Due their unique plumage color and structure the Ruddy Duck is a straightforward identification that cannot be confused with any other species.

In Mexico the Reddy Duck breed locally throughout Baja California and Baja California Sur and on the Pacific Slope from the United States border south to the central volcanic belt and southern Morales. They are year-round residents of western Mexico from Baja California south to Chiapas. They are absent from the Atlantic Slope from southern Veracruz to Belize including Yucatán Peninsula. Northern populations found in Canada and the United States are medium distance migrants.

From a conservation perspective the Ruddy Duck is currently considered to be of Least Concern with expanding, widely distributed populations. They are not heavily pursued by hunters and viewed with disdain; however, they are shot at a level of 50,000 individuals annually. Their long-term survival is dependent upon the retention of their wetland breeding territories.