It was easy to spot an emperor penguin with a hatching egg, says Stefan, because the father would frequently lift up his brood pouch to check on the chick’s progress. The problem was finding a bird facing the right direction at the crucial moment in the few minutes of good light available each day.

While his partner is away hunting at sea, the male endures the bitter Antarctic winter, without feeding, as he incubates their single egg. After a gruelling 65 to 75 days, the egg begins to hatch. Stefan watched the tiny chick struggle to crack the shell. ‘It kept closing its eyes and looked exhausted,’ he says.