CASES OF MASS RUINING NEST-BOXES BY BROWN BEAR (URSUS ARCTOS)

摘要

At the beginning of summer the diet of brown bear (Ursus arctos) in northern boreal forests often contains bird eggs and nestlings. Usually, the bear feeds on nests located on the ground, but it is also able to ruin nests in tree hollows. The only case in Karelia, when the bear attacked a nest-box for secondary cavity-nesting birds was described for the territory of the Ladoga Ornithological Station "Mayachino". The first case of ruining nest-boxes by brown bear was registered in the territory of the "Kivach" Nature Reserve. In 2015, the bear destroyed eggs and nestlings of pied flycatcher (Ficedula hypoleuca). At the same time, the influence of natural predators of nests typical of Karelia, such as great spotted woodpecker (Dendrocopos major), weasel (Mustela nivalis), American mink (Neovison vison) and marten (Mustela erminea), on the success of breeding in secondary cavity-nesting birds was insignificant.