The pine marten’s Martes martes ecological niche and its relationships with other vertebrate predators in the transitional mixed forest ecosystems of northern Belarus.

The pine marten’s Martes martes ecological niche and its relationships with other vertebrate predators in transitional coniferous - small-leaved woodlands of northern Belarus were studied. Data on dietary composition and distribution patterns of pine martens were gathered under differing conditions of food supply and across a range of landscape types and seasons. Also, similar data were gathered from the following predator species: the weasel Mustela nivalis, the polecat Mustela putorius, the red fox Vulpes vulpes, the raccoon dog Nyctereutes procyonoides, the Ural owl Strix uralensis, the tawny owl Strix aluco, the Tengmalm’s owl Aegolius funereus, and the pygmy owl Glaucidium passerinum; these data were used in the calculation of ecological niche overlaps between the pine marten and these predatory species. Variations in the abundance of the main prey were monitored. The data showed that the pine marten acted both as an active predator, mostly taking many species of rodents and birds, and as a gatherer, feeding on fruits and scavenging for carrion. The winter density of bank voles drove pine marten numbers. Also, the biomass of carrion was a crucial factor determining predator density in late winter. The analysis undertaken of the two predatory guilds (generalist predators and rodent eaters) suggested that the species, being nearly equally adapted to survive in the available habitats, coexisted stably and competitively limited the population densities of each other. We revealed significant partioning in the habitats and/or food resources that promoted the species’ coexistence. However, the naturalised raccoon dog has negatively affected the pine marten population, and the particular cause seems to be competition for carrion in late winter