Butterfly extinctions in European states: do socioeconomic conditions matter more than physical geography?

Aim To distinguish the effects of physical geography and socioeconomic conditions on the extinction of butterflies in European states, and to compare patterns influencing extinctions with patterns influencing species richness. Location Europe. Method Per-state species richness and extinctions were taken from the Red Data Book of European Butterflies, and their relationships with physical geography and socioeconomic predictors were analysed using regression analysis. Two hypothesis were explored: (1) extinctions are related primarily to identical physical geography factors that influence species richness; and (2) extinctions are influenced primarily by human pressure on natural biotopes and follow correlates of modern land use. Results Extinctions and richness are not correlated. Richness increased towards low latitudes and with biotope and topographic heterogeneity, and decreased in states affected by Quaternary glaciation and on islands. The only socioeconomic correlate was human density, exhibiting a weak negative effect. Extinctions were negatively correlated with area and with biotope and topographic heterogeneity. They peaked in regions with mild climate in central latitudes. The strongest socioeconomic correlate was high density of railways, interpreted as a proxy of early industrialization. Further correlates were human density and urban employment. Main conclusion Topographic and biotope heterogeneity predicts both high species richness and low extinction rates. Losses of butterflies result from a complex interplay of geography and relatively recent economic history, as low topographic heterogeneity and flat relief favoured the early advent of industrialization and intensive land use.