Roe deer Capreolus capreolus feeding on yew Taxus baccata in relation to bilberry Vaccinium myrtillus density and snow depth

The extent of roe deer Capreolus capreolus feeding on the highly toxic yew Taxus baccata during winter was quantified from 1989-1994 in areas with varying density of bilberry Vaccinium myrtillus. Yew was most heavily harvested by roe deer in areas with low densities of bilberry. In areas with high densities of bilberry shrub, roe deer started browsing on yew when snow depth increased and reduced access to the field layer. However, in areas with low densities of bilberry, roe deer browsed heavily on yew also when snow was absent. Our observations suggest that roe deer may be the main factor affecting yew survival in areas where other preferred feeding plants are not available.