Staying cool or staying safe in a human-dominated landscape: which is more relevant for brown bears?

Abstract

Pigeon et al. (2016) Staying cool in a changing landscape: the influence of maximum daily ambient temperature on grizzly bear habitat selection. Oecologia 181:1101. doi:10.1007/s00442-016-3630-5 analyzed the effect of ambient temperature on the habitat selection of grizzly bears (Ursus arctos) in Alberta, Canada. They concluded that temperature played a significant role in bear habitat selection and that it was unlikely that human activity introduced biases to the habitat selection of bears. However, Pigeon et al. did not consider variables related to human activities in their analyses. They also misinterpreted previous research that has accounted for temperature in the habitat selection of brown bears. There is much literature published on the negative effects of human disturbance on wildlife in general and on bears in particular. Downplaying the role of human disturbance could have important negative consequences if, in fact, human disturbance were a more important factor than thermoregulation. Indeed, dismissing the importance of human influence, in the face of contradictory evidence, could tempt managers to disregard an important factor that is difficult and often unpopular to deal with in their conservation plans.

Habitat Selection by Brown Bears with Varying Levels of Predation Rates on Ungulate Neonates

“…In this season, bears also avoided areas close to human disturbance and selected habitats closer to deciduous forests, which are also preferred by moose [45], despite deciduous forests only representing 3.92% of the study area. In the post-calving period, habitat selection of bears further from gravel roads likely reflects human avoidance, as documented in several earlier studies for the Scandinavian bear population (e.g., Ordiz et al [30,54]), in a season when bears rely on berries and several recreational human activities are more common than in spring.…”

Fluctuating mast production does not drive Scandinavian brown bear behavior

“…Conversely, Pigeon et al (2016) reported that brown bears in Alberta, Canada, where temperatures are similar to Sweden, adjusted their habitat selection and avoided clearcuts, a habitat with potentially high food availability, during the hottest part of the days. For our study area, Ordiz et al (2017) suggested that bears primarily adjust their habitat use to avoid humans, rather than in response to warm temperatures. We did not control for the effects of habitat composition or road density on behavior.…”

Testing the influence of habitat experienced during the natal phase on habitat selection later in life in Scandinavian wolves

“…Such patterns have not been documented earlier, to our knowledge, yet it might be expected in an animal with cognitive abilities, such as the wolf. It has been shown that brown bears Ursus arctos display human avoidance at all spatial and temporal scales 24 , sometimes in clear response to specific human activities. For instance, bears become more nocturnal when annual hunting seasons start 58 and right after encountering humans in the forest 59 .…”

“…For example, humans can be an important source of disturbance and pose a mortality risk for large carnivores 22,23 , which generally results in the avoidance of humans, anthropogenic infrastructures and areas of high human activity e.g. 24 . Therefore, experiences with humans during the natal phase may be a stimulus that reflects on carnivore behavior and habitat selection throughout the whole life of an individual.…”