"Collins Wildlife Trust Guides" are field guides illustrated with photographs that can be used to identify butterflies in the wild. Every species is comprehensively illustrated with specially chosen photographs, so that no matter what part of the butterfly you see, or what sex, there is a photograph. The text also covers details needed to confirm the identification, plus information on the biology of each species. There is also a distribution map for every species, showing where it occurs in Europe. The guides are published in association with the Wildlife Trusts, who have over 250,000 members in the UK.