These days the RSPB (the Royal Society for the Protection of Birds) has over a million active members. Watching birds is one of the most popular of all leisure pursuits. For many people it offers a tranquil day out at a picturesque nature reserve with a nice tea shop; for many more - the fabled twitchers beloved of media jokes - it is a fiercely competitive sport that requires a pager, a fast car and enormous stamina. It is a hobby that has spawned a big and lucrative industry, to supply anything from birding holidays in South America to state-of-the-art telescopes and even bird-call ringtones for a mobile phone. Kenneth Clarke is a birdwatcher; so, apparently, is Jarvis Cocker. Why, and how, have people watched birds through the ages? Stephen Moss's book traces the history and development of this singular pastime, on both sides of the Atlantic, all the way from Gilbert White, the country parson who wrote The Natural History of Selborne in the 18th century, through the British servicemen who studied Black Redstarts from their German prisoner-of-war camp, to today's driven life-listers and twisters who think nothing of hurtling the length of the UK by planes, automobiles and even boats in pursuit of a Grey-Tailed Tattler temporarily landfallen in the Shetland Isles.