Emperor penguin (Aptenodytes forsteri) vocalising. It uses a frequency-modulated whistle when asking for food, and to locate its parents. This is the only penguin to breed during the Antarctic winter. Congregating at colonial nesting areas inland, each pair produces a single egg, which the males incubate on their feet. After the egg hatches in around mid-July, the male and female take it in turns to shelter the chick and feed it with regurgitated fish following foraging at sea. The chicks acquire their juvenile plumage in around November. Adults stop feeding them around this time, and by December or January the chick will travel to the sea with the colony and begin feeding there. Photographed in October, in Antarctica.