Foraging strategies of wolverines within a predator guild

Within the predator guild, wolverines ( Gulo gulo (L., 1758)) have evolved as generalist predators and scavengers on prey killed by other predators. The recovery of wolves ( Canis lupus L., 1758) in the boreal forests of southern Norway during the late 1990s may have triggered consequent recolonization by wolverines through increased carcass availability. We investigated winter foraging behavior of wolverines in the boreal forest with regard to wolf, lynx ( Lynx lynx (L., 1758)), and red fox ( Vulpes vulpes (L., 1758)) presence. We followed 55 wolverine tracks in the snow from at least nine individuals for a total of 237 km during the winters of 2003–2004. We documented 19 moose ( Alces alces (L., 1758)) and 4 bird carcasses, and no successful hunts. Wolverines did not follow guild species trails directly to carcasses; however, they did change their movement patterns after red fox encounters. While wolverines were more active at higher elevations, the probability of encountering a wolf was higher at lower elevations, suggesting a spatial separation between wolverines and wolves. Although wolverines seem to depend on wolf for carrion during winter, they did not use wolf trails to find carcasses. This may indicate that wolverines reduce risk of intraguild predation by avoiding direct confrontation with wolves.