An inflated conservation load for European butterflies: increases in rarity and endemism accompany increases in species richness

Abstract

The addition of species to the European butterfly list since 1983 has resulted in a number of highly significant changes. Most important are the increases in the number and proportion of endemics and of rare species, and a regional excess of species and endemics for southern Europe compared to northern Europe. There is also a surplus of Lycaenidae and Satyridae compared to other families, and an increase in species per genus associated with the reduction in genera. These additions raise two issues. First, the potential conservation load for European butterflies is inflated at species level. This is especially the case for southern Europe, which has disproportionate increases in rare and endemic species, more particularly if rarity and endemism are found to equate with threat of extinction. Second, the inflation in rarity and endemism suggests that there is a trend to promote ever more local populations (races, subspecies) to species. The taxonomic status of species being added to the list, a quarter of which are regarded as doubtful, is increasingly difficult to determine. Consequently, there is a danger that this may call into question the validity and objectivity of taxonomic practices, and of databases dependent on them, used by conservation. Revision of higher and lower butterfly taxa is urgently required.