Why do birds sing at dawn? What's the slowest a plane can fly without stalling and falling out of the sky? And how long can you keep a tiger cub as a pet? Will We Ever Speak Dolphin?, the eagerly-awaited new 'Last Word' collection, has the answers to these questions and many more. Seven years on from Does Anything Eat Wasps?, the New Scientist series still rides high in the bestseller lists, with well over two million copies sold. Popular science has never been more stimulating or more enjoyable.