$Poliocephalus [poliocephalus] rufopectus Sibley & Monroe,1990,Distribution and Taxonomy of Birds of the World,p.295.
Occurs mainly in open water.Inlets fringed with vegetation in large lakes;low altitude lakes & sluggish rivers,esp.forested areas;estuarine marshes.Ouside breeding season,along coast,frequenting estuaries,bays & areas with kelp,where Non-breeders all yr
"Season fairly irregular,some populations apparently breeding at any time of year;most laying Oct-Jan,becoming steadily later towards S;Peruvian populations Sept/Oct..."(HBW,1,p.192)
Generally spends non-breeding period in coastal waters,sometimes gathering in flocks of several hundred birds. At onset of breeding, birds move back to fresh water.Strays onto open sea some distance from land: e.g. 1 bird at least 40Km off coast of northeast Argentina;at least 6 records from Falklands.