Knut

The death of Knut, the world's most famous polar bear, has reopened the debate on the ethical minefield of man's relationship with wild animals. So should polar bears be kept in zoos, asks Tom de Castella.

Knut was born in Berlin Zoo in December 2006. Rejected by his mother, he was put in an incubator and brought up by humans.
His abandonment, cute looks and close relationship with the charismatic zookeeper Thomas Doerflein, turned him into a huge star. He became an environmental symbol, acting as a mascot for the German government's campaign against climate change and being superimposed into a photograph with Leonardo DiCaprio for Vanity Fair's Green Issue in May 2007.
But news of his premature death at the weekend has spurred on those who question both the way Knut was treated and the very fact polar bears are in zoos at all.