Use of marshlands by Common Cranes in winter in south-western France

Abstract

The number of Common Cranes (Grus grus) wintering in the main wintering grounds in SW France increased from 25 in 1977 (first observation year) to 2500 in 1988. The annual variation observed around this general tendency can mainly be explained by autumn rainfall, which causes early flooding of the marshland used by the cranes . The night roosts are located in water basins and low heaths . During the day, the cranes prefer the low heaths, where they feed intensively. Five micro-habitats, defining an after-fire succession, are described in the low heaths . The regrowth of the vegetation after fires caused by military activities is rapid and the cranes seek out zones undergoing recolonization . The management of the heaths by fire seems to favour the cranes .