Ever looked at a bird & thought 'I wonder why birds sing'? Find the answer to this & many more intriguing questions about birds here How do ducks on frozen ponds stop their feet from freezing solid in winter? Do birds sleep standing up? Why do some species migrate yet others don't? And do birds have kneesstephen Moss answers 450 questions aimed at birdwatchers of all levels conveying a veritable feast of bird-related information in his friendly & accessible style Drawing on up-to-date research & illustrated with more than 200 colour photos Do Birds Have Knees? will enthral amuse & enlighten everyone with an interest in birds