Long‐term land‐use changes and extinction of specialised butterflies

Abstract

Abstract. 1 Land-use change in 450 ha in southern Sweden between 1814 and 2004 was recorded. Butterflies and burnet moths were surveyed in 1904–1913 and 2001–2005. 2 We explore if local extinctions were related to land-use changes and species attributes. 3 Land use changed drastically over the 190-year period, and the largest relative change occurred for hay meadows with late harvest, which decreased from 28% to 0%. The area changed from grasslands and grazed forests to being dominated by timber forests. Previous open grazed mixed woodlands changed to spruce plantations with clear-cuts. 4 Of the 48 resident butterfly and burnet moths found a century ago, 44% have become extinct. The extinct Aporia cratægi, Colias palaeno, and Leptidea sinapis were abundant 100 years ago and had their highest densities in flower-rich glades in forest, a habitat which no longer exists. 5 The butterfly extinctions could be predicted from species-specific attributes as a short flight length period (P < 0.02), narrow habitat breadth (P < 0.02), small distribution area in Europe (P = 0.033) and possibly larvae food plant nitrogen class (P < 0.06). In a multiple logistic regression, the flight length period was the only significant variable because the independent variables were intercorrelated. 6 We conclude that the most important factor explaining the high extinction rate is that flower-rich habitats have disappeared from both woodlands as well as from open farmlands. The most sensitive species are specialised species with a short summer flight which have gone extinct. Only the most unspecialised species still persist in the current landscape.