Manuscript / Niche separation between the weasel Mustela ...
Niche separation between the weasel Mustela nivalis and the stoat Mustela erminea in Belarus
Vadim E. Sidorovich, Alexey G. Polozov & Irina A. Solovej
Three main niche components (diet composition, habitat use and diel activity rhythms) were chosen to examine how the weasel and the stoat, both specialised predators of small rodents, could permanently coexist in Belarus. The research was carried out in temperate forests of Belarus, in two study areas with different environmental conditions: 1) continuous dry land forest interspersed by variety of swampy biotopes and aquatic ecosystems (Paazerre, northern Belarus); 2) extended wetland with large forest patches (Palesse, southern Belarus). The habitat use and diel activity rhythms of seven weasels and eight stoats were analysed by radiotracking over about 300 km2 in Paazerre. Also, snowtracking was applied to study the habitat use by the two mustelid species. Diet composition was examined by analysing 365 scats of weasels and 606 scats of stoats. Our results suggest that while the weasel and stoat occur in close proximity to each other, they use different micro-habitats, are most active at different times of the day, and prey primarily on different small rodent species. Most weasels selected forest and forest edge habitats, where they predominantly preyed on smaller rodent species (bank voles Clethrionomys glareolus and Apodemus mice); stoats selected wetlands, especially open grassy marshes, and preyed more frequently on larger rodents such as water voles Arvicola terrestris and Microtus voles. The weasel was mostly diurnal and adjusted its activity to the seasonally changing length of daylight, whereas the stoat was much more active in twilight and during the night.
Key words: Belarus, diet, diel activity rhythm, habitat selection, stoat, weasel