Assessing cumulative human impacts on northern woodland caribou with traditional ecological knowledge and resource selection functions

Woodland caribou (Rangifer tarandus caribou) are federally listed and declining across Canada because of the cumulative impacts of human infrastructure development. The Atlin northern mountain herd, in the territory of the Taku River Tlingit First Nation (TRTFN), British Columbia, is less affected by development than southern herds. However, recent low productivity in this herd suggests that the impacts of development (i.e., roads, mines, cabins and towns) may be accumulating. To predict the cumulative impact of human development on the Atlin herd, we developed seasonal resource selection functions (RSF) at 2 spatial scales with data from 10 global positioning system collared caribou. We modeled habitat selection and assessed cumulative effects by estimating the zone of influence (ZOI) around several types of human development. At the landscape and home range scale caribou avoided the ZOI and selected pine-lichen forests in winter and alpine habitats in summer. Approximately 8 and 2% of high quality habitat was lost due to avoidance of current development at the landscape scale in winter and summer, respectively. Future development of access roads to 2 mines would cause a further loss of 1% of high quality habitat. Negotiating the complex political dynamics that surround caribou conservation often requires new approaches to management and recovery planning. The incorporation of traditional ecological knowledge (TEK) with Western science could improve efficiency of management decisions and enhance the validity and robustness of ecological inferences. Therefore, we evaluated how well RSF and TEK habitat models predicted current woodland caribou observations and compared the spatial predictions of both modeling approaches. Habitat suitability index models were generated from TEK interviews with TRTFN members. Though comparison of habitat ranks between the 2 models showed spatial discrepancies in some cases, overall, both approaches had high model performance and successfully predicted caribou occurrence. Our results suggest TEK can be used to identify caribou habitat and is a useful approach in northern ecosystems that frequently lack long-term ecological data that are needed to inform management decisions. Combining TEK-based habitat suitability index models with cumulative effects assessments will facilitate recovery goals for woodland caribou across northern Canada