Behavioral and physiological stress responses of barren-ground caribou (Rangifer tarandus groenlandicus) to industrial ice roads

Recent and dramatic declines of barren-ground caribou (Rangifer tarandus groenlandicus) in northern Canada have been associated with the effects of climate change, natural population fluctuations, and human disturbance. Past research has revealed that caribou were displaced by industrial activities. These broad-scale distributional changes imply fine-scale behavioral and stress responses. In the central Northwest Territories, Canada, diamond mines and their supporting infrastructure, including winter roads, lie across much of the winter range of a number of populations of caribou. We investigated the fine-scale, mechanistic effect of these disturbance features on the behavior and stress physiology of caribou adjacent to an ice road used to transport industrial materials. We modeled the relationship between the prevalence of observed behavioral category as well as glucocorticoids extracted from fecal pellets and a variety of environmental and disturbance variables, including the distance to the ice road. Proximity to the road was associated with a decrease in time spent foraging and an increase in walking behavior. We did not find a relationship between levels of glucocorticoids in fecal pellets and proximity to the road. These results contribute to efforts to understand and manage the effect of industrial disturbance, including ice roads, on barren-ground caribou.