The Chubut steamer duck or white-headed flightless steamer duck (Tachyeres leucocephalus) is a flightless duck endemic to Argentina. It is the most recently recognized species of steamer duck, being described only in 1981. This is because it is only found along a rather small and sparsely populated stretch of coast around the Golfo San Jorge in southern Chubut and northern Santa Cruz Provinces, and because steamer ducks in general look fairly similar in plumage. Description Adult male Chubut steamer ducks have white heads with a bright yellow/orange bill with a black nail. Their webs and feet are yellow/orange with black claws. The rest of their plumage includes mostly grey bodies and white bellies. While the male is molting his bill turns to a duller yellow/orange. Adult female Chubut steamer ducks have brown heads and necks with small white line going from the back of the eye to the fore-neck. Their bills have a greenish/yellow color. The Adult female Chubut steamer duck looks very similar to the juvenile. Range The Chubut steamer duck was originally thought to only be found strictly in the southern coast of the Chubut province in Argentina. However it is now known to have a larger range from the southern portion of the San Matías Gulf to Islote Chato. The crucial populations for this species are found in Bahía San Gregorio (Argentina) [1], Bahía Melo [2], and Caleta Malaspina[3]. These three crucial populations are all located in the San Jorge Gulf. Diet The Chubut steamer duck's diet consists of molluscs and crustaceans which it gets through diving, upending and dabbling like most other ducks. They also are known to look on land for food, but stay close to the coast. Breeding The breeding season goes from October to February with nests made out of grass, sticks and litter from the high tide. Their nests, typically containing 5-6 eggs, can be found densely clumped together or alone. This species breeds on 500 km of coastline from the Chubut River mouth to the Chubut and Santa Cruz province boundary. There are an estimated 3,700 breeding pairs of the duck species. In a study of 292 km of continental coastline and 59 km of island coastline from 2004 to 2006 (three breeding seasons) 170 nests were found and out of those found nests 169 were found to be on islands/islets and only one on continental coastline. All of the nests