DWARF SHRUB BERRIES IN THE DIET OF THE BROWN BEAR (URSUS ARCTOS) IN SOUTHERN TAIGA: EXAMPLE OF THE CENTRAL FOREST STRICT NATURE RESERVE

Abstract

The paper examines some features of brown bears’ feeding on dwarf shrub berries (bilberry, cranberry, cowberry and black crowberry) in the southern taiga subzone, in spruce forests and on raised bogs of the Central Forest Nature Reserve and its protection zone. The most significant berries in the animals’ diet are bilberries and cranberries. According to the results from 279 sample plots, average consumption by bears per 1 m2 was 74.2 g of bilberries out of 114.5 g abundance (64.8 %) and 109.5 g of cranberries out of 183.3 g abundance (59.8 %). In the most productive years, the removal of bilberry can reach 76 %. We analyzed the rate of bilberry removal from three main types of spruce forests: bilberry-Sphagnum, Sphagnum and bilberry-horsetail-Sphagnum. The removal rate was the highest in the bilberry-horsetail-Sphagnum spruce forest, and amountedto 135.7 g/m². The analysis of 474 scats revealed a high significance of bilberry in the second half of the summer (EDEC = 58 %). The significance of cranberry was the highest in autumn (EDEC = 8.9 %) and early spring (EDEC = 4.0 %), while cowberry contributed to the diet significantly only in autumn (EDEC = 1.6 %). Black crowberries are very rare in the animals’ diet (EDEC = 0.5 %). Energy gains from feeding on bilberries are 42.3 (up to 72.7) kcal/m², while cranberries provide 50.4 kcal/m². The greatest factors for the rate of consumption of berries by bears are the dwarf shrubs’ general yield and nuisance from humans.