Vol. 75 (3) 2023

ARTICLES

Characteristics of Dens of Brown Bear Ursus arctos Linnaeus, 1758 (Carnivora: Ursidae) in Bulgaria

Vladimir R. Todorov1,*, Venislava V. Spasova2, Daniela M. Simeonovska-Nikolova2, Ivo S. Ihtimanski3, Katerina T. Zareva-Simeonova2, Nikolai Dolapchiev1 & Raycho Ganchev4

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*1Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria
2Department of Ecology and Environmental Protection, Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria
3Department of GIS and Cartography, Faculty of Geology and Geography, Sofia University “St. Kliment Ohridski”, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria
4Independent Researcher, 67 Metodi Kusev Blvd., 6000 Stara Zagora, Bulgaria

https://doi.org/10.71424/azb75.3.002717

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Abstract
The hibernation is a critical period for the survival and reproduction of the brown bear. By this reason, the knowledge of the dens’ location and characteristics is crucial for planning management actions to reduce disturbance in these areas. In order to locate bear dens, field trips were conducted in the two subpopulations of the brown bear in Bulgaria, i.e. in Starа Planina Mountain and Rila-Rhodopean massif in the period May – October 2022. Totally, 45 dens were studied. We measured the width, length of entrance and depth of the dens and considered the presence and type of bedding in each den. The elevation, aspect, slope, surrounding habitat and distance from roads, settlements and large rivers were analysed. The results showed that all located brown bear dens were in rock cavities, most often in high rocky terrain. Majority of dens were with a southern aspect and situated in forests close to large rivers. In Stara Planina, the dens were at higher altitudes while, in Rhodope Mts, they were at steeper slopes and were significantly closer to roads and settlements. These differences call for different management approaches in the regions of the two subpopulations in order to maximise the conservation efforts in each of them.

Key words
den preferences, Brown bear conservation, spatial characterization in GIS

How to Cite
Todorov V.R., Spasova V.V., Simeonovska-Nikolova D.M., Ihtimanski I.S., Zareva-Simeonova T.S., Dolapchiev N. & Ganchev R. 2023. Characteristics of Dens of Brown Bear Ursus arctos Linnaeus, 1758 (Carnivora: Ursidae) in Bulgaria. Acta zoologica bulgarica 75 (3) 331-341.

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