Overview:Antarctica's penguins are some of the most endearing animals on earth, but behind the comical behaviour is a continual struggle to survive the deadly cold. Each penguin has its own strategy - some rely on thick down coats and fat reserves, others migrate north for the winter or stay on volcano-heated islands. Life in the freezer is getting even tougher as Antarctica's climate starts to change. The ice-loving Emperor penguins may be the first to lose out, but their cousins, the King penguins, are waiting in the wings to take over. All penguins must draw on their ability to defy the odds if they are to survive their greatest challenge yet.