Gränsöverskridande älgförvaltning: ekologiska förutsättningar

Predator-prey interactions are shaped by several factors, including landscape features and hunting modes of predators. Within anthropogenic landscapes, humans can reshape predator-prey interactions by influencing the density, behaviour and survival of both predators and prey through activities such as hunting, forestry practices and land use. In Scandinavia, harvest has become the main mortality source for moose (Alces alces), and with the return of large carnivores, moose now face mortality risk from multiple sources.The objectives of this study were to: 1) assess the spatial attributes of hunter-killed and wolf (Canis lupus)-killed moose during and after the hunting season to determine if the risks generated by wolves and hunters were contrasting or overlapping; 2) investigate habitat selection of moose in relation to the spatiotemporal distribution of hunting and wolf predation risk; and 3) evaluate moose calf mortality during summer and winter in relation to risk from both humans and large carnivores (wolves and brown bears, [Ursus arctos]) and other variables.Spatiotemporal patterns of hunting and predation risk correlated to both environmental and anthropogenic features. When comparing the spatial characteristics of hunter-killed and wolf-killed moose, we found contrasting risk patterns generated by hunters and wolves. During the hunting season, moose avoided areas of high hunting risk during the day, while their habitat selection was not affected by hunting risk at night. After the hunting season, moose habitat selection was not influenced by hunting risk during the day or at night. Moose selected areas of high wolf predation risk both day and night during and after the hunting season.Moose calf mortality in summer varied significantly between years but was not related to predation, climatic or environmental variables. In winter, calf mortality correlated positively to snow depth and clearcuts/young forests in the presence of wolves and increased hunting risk. Overall, environmental and anthropogenic features were more important in explaining moose presence and browsing damage than wolf presence.These results indicate that while both hunting and wolf predation risks varied spatiotemporally, moose responded only to the stronger, more predictable mortality source, i.e. hunting. We conclude that hunting has functionally replaced predation by wolves and bears on moose during the last century in Scandinavia.