A review of butterfly conservation in central southern Britain: I. Protection, evaluation and extinction on prime sites

Abstract

A major review of butterfly conservation was conducted from 1985 to 1987 in central southern Britain where semi-natural habitats are higly fragmented. Of the 308 sites surveyed, 67% had been protected as statutory Sites of Special Scientific Interest, but three nationally and 20 regionally important sites were not notified. Over half the sites were privately owned and about 23% were owned or managed by conservation organisations. Of the 2248 definite colonies of key species identified, 384 had become extinct, mostly over the last 40 years. Two of the 29 key species had become totally extinct on the study sites and the documented (minimum) loss rate amongst Red Data Book or Scarce species had been 37%. Moreover, the losses had been just as great on protected as on unprotected land, and for many species this trend continued in the 1980s. The main conclusion of the study is that many of Britain's rarer species are not being conserved effectively under the present system of site protection and a comprehensive conservation strategy for butterflies is needed. The results have wider implications for the conservation of biodiversity in fragmented landscapes and suggest that greater emphasis should be placed on the management of habitat fragments and the better integration of protected areas into the surrounding landscape.