Emperor chicks with an adult at Snow Hill Island colony, Antarctica 5 Emperors incubate their eggs during the long dark southern winter months. Courtship displays are intricate but copulation is quick and the female lays a single egg in May or June. She then passes it over to her mate to incubate and she’s off. She spends the next nine weeks at sea, feeding. The male carefully balances the egg on his feet for between 65 to 75 days to keep it warm and off the snow surface in a specially adapted brood pouch before it hatches.

Photograph: Bryan and Cherry Alexander/WWF