WOLVERINES AND THEIR PREY IN SOUTHERN NORWAY

Wolverines (Gulo gulo) recolonized the Snohetta plateau in southern No rway in 1976-1979 after an absence of over 50 years. This is presently the southernmost part of the wolverine's distribution and the only ar ea where it coexists with wild reindeer (Rangifer tarandus) in western Europe. Other, larger predators in the Scandinavian ecosystem, the wo lf (Canis lupus), lynx (Lynx lynx), and brown bear (Ursus arctos), hav e been absent from the area since the beginning of this century. We mo nitored wolverine numbers, reproduction, and diet during the denning p eriod and studied the effects of abundance of different prey species o n wolverine reproduction. Although there were differences in productiv ity among maternity dens, the main factor influencing the number of wo lverine cubs surviving was the abundance of small rodents (p = 0.0002) . Although small rodents constituted the main factor explaining variat ion in cub numbers, the basic prey during the denning period was reind eer. Hares (Lepus timidus) accounted for a significant but stable part of the diet during the denning period. The wolverine was an important predator on sheep (Ovis aries), but we found no evidence that sheep a re an essential part of its diet.