In December 2006, the polar bear Knut was born in the Berlin Zoo. Because Knut was rejected by his mother, he was raised by a caregiver. The media paid a lot of attention to the animal, even to the extent that the German government used him as a mascot against global warming. Polar bears have become an endangered species as a result of global warming and pollution.

Knut drowned in the water of his enclosure in 2011 as a result of meningitis that led to an epileptic seizure.