The decline of a brown bear Ursus arctos L. population in central South Norway

Abstract

The brown bear Ursus arctos L. was studied in the Vassfaret area of Norway for the 40-year period 1949–1988. More than 800 bear reports, mostly from untrained observers, were analysed, critically evaluated and 35 verified as true. During the whole period there was a clear concentration of observations in a core area of about 1300 km2 and a less dense and more patchy occurrence in the surrounding area of about 25 000 km2. Reproduction was unconfirmed, as no observations of females with cubs or young could be verified. Results from tracking and other special studies suggested that the population consisted of only a few individuals. A tracking study during 1970–1972 showed at least one bear to be present, but a similar study in 1991 found none. There was a clear tendency of a decline, probably caused by heavy hunting before the study, and habitat deterioration by human intrusion during the study period.