Previously published in hardback and now made available in paperback, this ground-breaking book is a must for all interested in butterflies, whether as conservation biologist, amateur or professional entomologist or as a student studying the phenomenon of butterfly populations as part of a number of biology, ecology or conservation courses. Recently, many British butterflies have suffered severe declines whole others have flourished and expanded in range. This is the first book to describe the results from a British scheme to monitor butterflies during this period of change. The Monitoring Scheme, initiated in 1976 by the senior author is based on.