Brown Bear (Ursus Arctos) (Carnivora, Mammalia) Dens of the Kronotsky Nature Reserve

Abstract

Seventeen brown bear dens were studied in the Kronotsky Nature Reserve (Russian Far East). The majority of dens were excavated in the ground. The dens were located mainly in the upper part of slopes with southwest aspects in birch forests, dwarf Siberian pine and alder patches. The structure of the dens was typical for brown bear ground dens. There are places in the basin of Shumnaya River in Kamchatka where brown bears prefer to set up their dens.Key words: brown bear, Ursus arctos, den, Kronotsky Nature Reserve. DOI: 10.18500/1684DOI: 10.18500/ -7318-2018 Dens areas are critical habitat for brown bears, and the animals select locations for their dens based on both, human activities and presence of suitable natural habitat (Schoen et al., 1987;McLellan, Hovey, 2001).The studies were carried out in the framework of the research program of the brown bears Ursus arctos Linnaeus, 1758 in Kamchatka region at the territory of the Kronotsky Nature Reserve in the Shumnaya River basin in 2005 -2006. Bear dens were found by searching in the habitat potentially suitable for dens, in places where bears were observed in post-denning period and by visiting the locations of animals with GPS-collars (Paczkowski et al., 2005).

Locations of dens with respect to space use, pre- and post-denning movements of brown bears in the Russian Far East

“…This behaviour is possibly caused by the fact that in Kamchatka, denning sites are located far from foraging areas. In particular, in the River Shumnaya basin, we found a place where the dens were concentrated (Seryodkin et al, 2018b), including the den of female №17. However, the main home ranges of the females were in the vicinity of the valley of Geysers and geo-thermal zones, where there are favourable feeding conditions, especially in spring.…”

“…The factors determining the choice of such places are the characteristics of the relief, microclimate and protective properties of the study area. Concentrations of brown bear dens have been observed under the most optimal conditions (Van Daele et al, 1990;Huber & Roth, 1997;Seryodkin et al, 2018b). Mass purposeful movements of brown bears in the pre-denning period have been recorded to places with high den densities (Kostoglod, 1979;Zavatskiy, 1987;Yudin, 1993).…”

Microhabitat characteristics of brown bear den areas

“…In the area of Velebit Nature Park, the largest number of caves had a south-facing exposure. According to Vaisfeld and Chestin (1993) and Seryodkin et al (2018), preference for southern and western exposures is typical of northern regions of the Far East, Russia, Yakutia (Sakha), Volga-Kama regions and the Carpathians (Vaisfeld and Chestin 1993). The heights of trees were significantly lower in the cave den areas on Mt.…”