Habitat use of the mountain hare Lepus timidus in summer:: the importance of different vegetation layers

The aim of the present study was to examine how the vegretation Structure of the forest, shrub and field and ground layer affect the habitat use of mountain hareS Lepas timidus Linnaeus, 1759 in summer (May-September) in southern Finland. The Structure of each vegetation layer in woodlots throughout the entire study area of 20 km 2 was measured. We analysed the vegetation data using principal component analysis (PCA) that arranged the woodlots along a gradient within each vegetation layer. Data on habitat use was gathered between 1998 and 2000 from 11 radio-collared mountain hares. The core areas of the home ranges of hares were determined and the vegetation structure of these areas was compared with the mean of the entire Study area (core area, periphery area and control area). A similar shrub layer was identified by PCA for seven out of the 11 hares. Hares preferred thickets of willow Salix spp.. downy : birch Betula pubescens, and spruce Picea abies. The hares did not Show a consistent preference for the forest and ground levels. The results suggest that dense under-stories are important in the mountain hare's habitat use, probably because they, offer both food and shelter.