The greatest richness of butterflies epcies clearly coincides with mountainous areas: the Cantabrian Mountains, the Pyrenees, the Alps, the Apennines, the Dinaric Alps, the Carpathians and the mountains of the Balkans, which host numerous species of very restricted range. Looking at butterflies species richness from a national perspectives, the top five EU countries are: Italy, France, Spain, Greece and Bulgaria.
Particularly high numbers of endemic species are found in the Alps and the Pyrenees. Other important concentrations of endemics are found in mountainous areas in Spain (e.g. Sierra Nevada and Cantabrian Mountains) and in Italy (the Apennines), as well as in the Balkans.
The distribution of threatened butterflies in Europe shows different patterns from the picture of the overall species diversity. Some of the threatened species still occur widely in Russia, for example Coenonympha hero, C. tullia, Colias myrmidone, Euphydryas maturna, Lopinga achine, Lyaena helle, Phengaris arion and P. teleius. In Central Europe, most threatened species can be found in Eastern France, Eastern Austria, the Romanian Carpathians and Eastern Poland. The reasons for this pattern are likely to be complex and involve a combination of a wide range of factors. One factor is that these regions hold concentrations of habitats used by threatened species, notably mountain grasslands and wet meadows. Another is that they coincide to some extent with general butterfly diversity and regions where eastern and western faunas overlap. Another factor is that species in western Europe that have suffered major historical declines and loss rates have now slowed to just below IUCN thresholds, whereas species in eastern Europe appear to be suffering from a more recent loss of habitat and hence decline in populations.
A high proportion of threatened and Near Threatened butterfly species are endemic to either Europe or EU, highlighting the responsibility that European countries have to protect the entire global populations of these species.