Behavioral and Physiological Responses of Scandinavian Brown Bears (Ursus arctos) to Dog Hunts and Human Encounters

Abstract

Innovations in biologging have offered new possibilities to better understand animals in their natural environment. Biologgers can be used by researchers to measure the impact of human disturbances on wildlife and guide conservation decisions. In this study, the behavioral and physiological responses of brown bears (Ursus arctos) to hunts using dogs (Canis lupus familiaris) and human encounters were assessed to better understand the impact of human outdoor activities on brown bears. In Scandinavia, brown bear hunting and the use of dogs during hunts is increasing in popularity. Nonetheless, not every hunt leads to a killed bear. This means that for each bear that is shot, multiple bears may be chased but not killed. In addition, bears can also be disturbed when encountering non-hunting humans. Heart rates, body temperatures, GPS coordinates and dual-axis activity data were collected from 52 simulated hunts (a simulated hunt using dogs with the bear allowed to flee at the end) and 70 human encounters (humans intentionally approaching the bear) that were carried out on 28 free-ranging female brown bears in two study areas in Sweden. The results showed that: (1) simulated hunts had a greater impact and induced a greater energy cost than human encounters; (2) the amount of time bears rested the day after the simulated hunts increased linearly with the duration of the simulated hunts, implying a lasting behavioral impact relative to the intensity of the disturbance. Although not tested in this study, brown bears that are repeatedly disturbed by dog hunts and human encounters may be unable to compensate the disturbances' energy cost, and their fitness may, therefore, be altered. If it is the case, this effect should be accounted for by managers.

Physiological and behavioural responses of moose to hunting with dogs

“…As a result, Swedish female moose might be more prone to flee compared to their North American conspecifics. Our results support previous research that hunting disturbances increase travel distance and higher maximum speed on the day of the approach compared to the day after disturbance in moose ( Ericsson et al, 2015b ; Sand et al, 2016 ), red deer ( Jarnemo and Wikenros, 2014 , Sunde et al, 2009 ) and brown bear ( Le Grand et al, 2019 ). In red deer, it is documented that escape strategies are linked to habitat type: red deer in fragmented and more open landscapes fled more often for longer distances, and at a higher speed, than red deer in homogenous forest landscape ( Jarnemo and Wikenros, 2014 , Sunde et al, 2009 ).…”

“…Moose might compensate for the increased energy consumption from hunting by increasing the resting time the day after, as we demonstrated. Another reason for the increased resting time is likely to be recovery from exhaustion as suggested in bears ( Le Grand et al, 2019 ). We recommend further studies to determine the effect of these events on the moose’s time spent foraging the day after a hunting situation.…”

“…How individuals respond varies among habitat characteristics, hunting pressure and hunting method ( Jarnemo and Wikenros, 2014 ). Hunting disturbance can result in increased resting time to compensate for increased energy consumption or to recover from the exhaustion ( Le Grand et al, 2019 ).…”

“…Sand et al (2016) found differences in the flight patterns between females with and without calves, as well as differences in flight patterns and reactions of moose in response to different dogs. Behavioural impacts, together with physiological responses, have been assessed in simulated hunts with baying dogs in brown bears ( Le Grand et al, 2019 ). During experimental days, compared to control periods, the authors noted higher HRs and T b , with the bears also travelling longer distances and at higher speeds.…”

Observing the unwatchable: Integrating automated sensing, naturalistic observations and animal social network analysis in the age of big data

“…foraging, grooming, etc. ), heart rates and body temperatures of recognizable individuals over time (Le Grand et al., 2019; Wassmer & Refinetti, 2019). The value of this added information is especially evident when combined with tracking technology that offers high‐resolution spatial data (Kays et al., 2015; Krause et al., 2013).…”