FIGURE 20 in Amphibians and reptiles in North Sweden: distribution, habitat affinities, and abundance (Classes: Amphibia and Reptilia)

FIGURE 20. Talus slopes and screes provide communal hibernation sites for Vipera berus, offering frost-free conditions also in case of early winter weather with little insulating snow cover. Such sites invariably face SW–SE and have early snowmelt that permits earlier spring emergence than in surrounding areas. Mating usually takes place here, after which vipers disperse to summer habitats visible in the background. This picture is from one of the northernmost known hibernation sites in Sweden at 68oN. Etnoluhtinvaara, Torne lappmark, Northern Boreal region. Photo: Stefan Andersson.