Behaviour of brown bears (Ursus arctos) when repeatedly approached by humans on foot

• Main Author: Stenset, Nina Emilie
• Format: Dissertation
• Language: English
• Subjects: Brunbjørn

Knowledge about encounters between humans and wildlife is important for conservation, management and policymaking, as well as for reducing conflict and negative interactions. There is general concern that an increased number of encounters might reduce wildlife flight responses. I investigated the responses of GPS-collared brown bears (Ursus arctos) in southcentral Sweden when repeatedly encountering humans on foot. Brown bears are generally wary of humans, and I therefore hypothesized that their behavioural response would not change with the number of experimental encounters. Bears were approached by observers 2 – 3 times per week for 2 – 4 weeks. The observers simulated recreational forest users during the approach and passed the bear’s initial location on an average distance of 29 m. A total of 11 solitary females (7 subadults and 4 adults) and 14 solitary males (6 subadults and 8 adults) were subject to an average of 6.6 approaches (SD = 1.19). I analysed flight response as distance between bear and observer when bear flight initiation (FID) occurred, the distance fled and time spent active after disturbance, combined with measurements of horizontal cover at the bear’s initial location. Data was analysed using generalized linear mixed-effect models with bear individual as random effect. No significant relationships were found between the number of approaches conducted on an individual and flight response. FID could best be explained by horizontal cover, age of the bear, activity and the interaction between age and activity. No significant relationships were found for flight distance nor duration. My findings support the hypothesis that brown bears are wary of people and does not alter their flight responses when repeatedly disturbed by humans on foot. SAMMENDRAG Kunnskap om møter mellom mennesker og vilt er viktig for forvaltning, vern og utforming av retningslinjer, samtidig som økt kunnskap kan redusere konflikt og negative interaksjoner. Flere har utrykt bekymring for at et økende antall møter mellom mennesker og vilt kan redusere viltets fluktresponser. Jeg har eksperimentelt undersøkt hvordan GPS-utstyrte brunbjørner (Ursus arctos) i sentrale deler av Sverige responderer når de gjentatte ganger møter mennesker til fots. Brunbjørner er generelt sky og unngår konfrontasjoner, og min hypotese var derfor at deres adferds ikke ville endre seg med antallet eksperimentelle møter. Observatører nærmet seg bjørnene til fots 2 – 3 ganger per uke over en perio