Nature Conservation Research: Заповедная наука (Nov 2020)
Home range, mobility and hibernation of brown bears (Ursus arctos, Ursidae) in areas with supplementary feeding
Abstract
Supplementary feeding, although a common practice, is seldom studied in terms of its effect on non-targeted species, such as the brown bear (Ursus arctos). We conducted a GPS-GSM telemetry study on nine individuals (out of about 100 supposedly inhabiting that area) with the aim to inspect how supplementary feeding stations affect home range size, mobility and hibernation. We formulated three hypothesis: 1) there is a correlation between the home range size and the density of feeding stations; 2) the influence of the artificial feeding stations is not changing during hyperphagia and outside the hyperphagia; 3) hibernation is affected by the density of feeding stations, regardless of the areas with trees in masting age present in the home range and forest age heterogeneity. Our analyses showed that the total home range averaged at 148.9 km2 (range: 24.6–605.1 km2) with 190.1 km2 for males and 76.9 km2 for females. Five out of nine brown bears never visited feeding stations and the density of feeding stations did not explain the home range size variability, thus not receiving evidence to support our first hypothesis. No evidence was found to reject the second hypothesis, while the third hypothesis was rejected for now with the proviso that our sample is not big enough for robust conclusions. The comparison of the home range size, as well as the average displacement distance during and outside the hyperphagia season showed no significant difference, contrary to the outcome of other published studies. Despite the variability of the masting areas proportions and age class heterogeneity, the lack of significant difference between the core area and the total home range for these two factors implied that these resources were not concentrated in the core area of the species, but were rather uniformly distributed throughout the whole territory. Neither density of feeding stations nor masting area proportions were found to be solely responsible for the formation of the hyperphagia home range. Additionally, the similarity in the sizes of the home range size during and outside the hyperphagia season suggested a balance between the variables forming the home range during these periods. Most of the brown bears in our study hibernate in their core area, predominantly in its very centre (0.1 percentile), as earlier hibernation than reported for this region from other studies was recorded. Further studies with a larger sample size on the role of the forest age heterogeneity and mast production on the formation of the home range are needed.
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