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. There are an estimated 3,700 breeding pairs of the duck species.
The two species that are commonly observed preying on Chubut Steamer duck eggs are the Kelp gull (Larus dominicanus) and Crested caracara (Caracara plancus).