Mapping interactions between winter recreationists and an endangered ungulate

Southern mountain caribou (Rangifer tarandus caribou) inhabit the interior mountain ranges of British Columbia, Canada. This population of woodland caribou is federally designated as threatened owing primarily to predation and habitat loss, but other compounding factors may impede their recovery. Of note are potential impacts from heli-skiing, a form of winter recreation that uses helicopters to transport skiers in wilderness areas. During late-winter, southern mountain caribou become range resident in high-elevation, old-growth forests and subalpine parklands. The deep snow characteristic of late-winter habitat offers reduced encounters with predators, and abundant arboreal lichens on which to feed; however, heli-skiing also occurs in these areas. Whether heli-skiing has any demographic impacts on caribou is unknown, but previous work has shown that heli-skiing can elicit short-term flight responses and longer-term reductions in space use and elevated stress levels. Furthermore, little is known about where skiing occurs or where helicopters transport skiers between lodges and ski areas, leaving regulating bodies with little information to guide management recommendations. We paired anonymized fitness tracker user data from the rasterized Strava global heatmap with 4 years of caribou global positioning system (GPS) location data to identify hotspots of potential interactions between heli-skiers and caribou. There were approximately 400 km² where the potential for conflict appeared high out of 3,116 km² suitable for heli-skiing. The majority of heli-ski operators have the capacity to reduce their interactions with caribou to almost zero through avoidance of key habitats and timing of use of that terrain. We recommend that heli-ski operators work with governmental managers towards the optimal use of tenures through rolling closures or the permanent diversion of ski runs away from high potential conflict areas.