A rare white penguin has been pictured in Antarctica. The Chinstrap penguin was photographed by naturalist David Stephens during an expedition to the Aitcho Islands. The penguins normally have black and white plumage but this one suffers from leucism, a condition that occurs in around one in every 146,000 penguins. It is different from albinism which is a complete lack of skin pigment. Instead it has pigmented eyes and a paler version of the normal penguins colouring.