Behavioral reactions of brown bears to approaching humans in Fennoscandia

Abstract

Human disturbance causes behavioral responses in wildlife, including large carnivores.Previous research in Scandinavia has documented that brown bears (Ursus arctos) show a variety of behavioral reactions to different human activities. We investigated how proximity to human settlements and roads, as proxies of human influence, affected brown bears' reactions to encountering humans. We analyzed experimental approaches to GPS collared bears, 18 males and 23 single females, in Sweden (n = 148 approaches) and Finland (n = 33), conducted between 2004 and 2012. The bears in Finland inhabited areas with higher human density compared to Sweden. However, the proportion of bears staying or moving when approached and the flight initiation distances were similar in both countries. In Sweden, the flight responses were not dependent on human densities or roads inside the bears' home ranges or the distances from the bears to roads and settlements. Brown bears in Fennoscandia live in areas with relatively low human population densities, but in many areas with high forestry road densities. Our results show that bears' flight reactions were consistent between areas, which is an important message for management, reinforcing previous studies that have documented human avoidance by bears at very different spatial and temporal scales.

A Standardized Method for Experimental Human Approach Trials on Wild Wolves

“…Overall, both changepoint analysis and UCL performed similarly well for detecting flight initiation. Hence, as previous studies have shown, both can be used successfully to detect flight initiation (Moen et al, 2012(Moen et al, , 2018Ordiz et al, 2019;Viljanen, 2019). However, both methods have limitations, and neither performed flawlessly in our study.…”

“…In this study, UCL detected all flights which were also confirmed by visual inspection. However, Moen et al (2012Moen et al ( , 2018 reported cases in which visual inspection indicated a flight, but speed did not exceed the UCL. Changepoint analysis does not require control data, and it requires less data preparation, as it can handle various data distributions.…”

“…Experiments in which human observers approach marked wolves can increase the knowledge about how wolves can be expected to respond to interactions with humans (Karlsson et al, 2007). Experimental human approaches have been done previously on species such as common buzzards (Buteo buteo) (Sunde et al, 2009a), reindeer (Rangifer tarandus) (Colman et al, 2012), red deer (Cervus elaphus) (Sunde et al, 2009b), moose (Alces alces) (Viljanen, 2019), polar bears (Ursus maritimus) (Andersen and Aars, 2008), brown bears (Ursus arctos) (Moen et al, 2012(Moen et al, , 2018Ordiz et al, 2013Ordiz et al, , 2019, lynx (Lynx lynx) (Sunde et al, 1998), and wolves (Karlsson et al, 2007;Wam et al, 2012Wam et al, , 2014. However, previous studies on wolves used VHF collars (Karlsson et al, 2007;Wam et al, 2012Wam et al, , 2014, limiting the level of detail at which the wolf response could be recorded without subsequent snow tracking (Karlsson et al, 2007).…”

Wolf Responses to Experimental Human Approaches Using High-Resolution Positioning Data

“…With this paper, we aimed to describe the flight response of seven wild GPS-collared wolves in Norway and Sweden by conducting experimental human approach trials. This is, to our knowledge, the first study assessing wolf flight responses toward humans with the use of high-resolution GPS data, which gives much more detailed and accurate information about flight intensity and flight patterns compared to VHF studies (Moen et al, 2012(Moen et al, , 2018Ordiz et al, 2019). High resolution GPS data makes it possible to re-construct details of the flight path without the need of snow tracking (Moen et al, 2012;Wam et al, 2012Wam et al, , 2014.…”

“…Responses to approaching humans have been studied previously in wolves using information from VHF-collars (Karlsson et al, 2007;Wam et al, 2012Wam et al, , 2014, and more recently in brown bears using high-frequency GPS data (Moen et al, 2012(Moen et al, , 2018Ordiz et al, 2019). In wolves, flight initiation distance (FID, i.e., the distance at which an animal flees from an approaching threat) was affected by wind conditions, with shorter FID when the wind was blowing away from the wolf, but not by horizontal visibility at the wolf 's location (Karlsson et al, 2007).…”