Winter home ranges and movements of polecats Mustela putorius in Bialowieza Primeval Forest, Poland

Polecats Mustela putorius Linnaeus, 1758 inhabiting a 4.5-km stretch of Orłówka stream in the Białowieża National Park, were studied by live-trapping in autumn and winter 1989 - 91. Ten polecats (6 males and 4 females) were captured. Every winter, from 1 to 3 polecats resided on the stream, and 1 to 3 transient polecats appeared on the river for short periods. None of the captured polecats persisted on the stream for three winters. The home ranges of resident males (estimated linearly along the stream) varied from 1 to 3.05 km, and those of females from 0.65 to 1.65 km. The home ranges of females were exclusive, but they could be completely overlapped by male home ranges. Radio-tracking of one resident male showed that its average daily movement distance was 1.1 km (range 0-2.1 km). During 19 days, it utilised 8 dens. Among polecats captured as pests by farmers in the village of Białowieża (n = 94) between 1960 and 1990, males predominated (sex ratio 1.7:1). Most individuals (54%) were captured in the cold season (November - February). The most likely cause of their appearance in the village was due to freezing of the rivers, which deprived the polecats of access to anurans and made them search for other food sources. From March till June, almost all the animals captured were males (of large body size). Their influx to the village might have resulted from their mating strategy: nomadism in search for receptive females. Polecats caught in autumn (males and females equally numerous) had low weights. They were the young dispersing from their natal ranges.