Abstract

The marking activity of brown bears was studied in the Kronotsky Reserve (eastern shore of the Kamchatka Peninsula) between 2002 and 2005. The goal of this investigation was to document communication mechanisms within the species. We recorded descriptions of bears rubbing and marking trees, as well as individual marking behaviour of bears in the Valley of the Geysers. We recorded 203 marked trees in an area of 2.5 km2 . Bears marked mostly stone birches (Betula ermanii ) with a mean diameter at breast height of 24 cm. Most trees were freshly marked with scratches or teeth marks and also exhibited scarring from previous years. Well-worn tracks were often recorded approaching marked trees. Regarding tree markings, 10.3% of trees were marked intensively, and 32% of trees were clustered. In addition, 88.9% of marked trees were located on ridges, and 79.3% were located on bear trails. The most intensive marking period was between May and June, which corresponded to bear mating season. The most commonly observed behaviour prior to marking was a rigid walking approach, rubbing on the trunk, and biting and removing tree bark. The high density and diversity of rubbed trees in the reserve should be considered a model for monitoring. The conservation of the Valley of the Geysers is intricately related to the wellbeing of the regions bears. Monitoring human impact on bears in the Valley of the Geysers, specifically tourism traffic, should include monitoring of the intensity and frequency of bear marking activity.