Assessing the health-fitness dynamics of endangered mountain caribou and the influence of maternal penning

The health of wildlife plays a crucial role in population demography by connecting habitat and physiology. Southern mountain caribou, a population of woodland caribou ( Rangifer tarandus caribou (Gmelin, 1978)) found in the mountains of southwest Canada, are facing significant threats. We evaluated the health of the Klinse-Za subpopulation within the central group of southern mountain caribou, which is part of an Indigenous-led conservation initiative aimed at enhancing caribou population growth through seasonal maternal penning. We collected health metrics from 46 female Klinse-Za caribou between 2014 and 2021. The health metrics included trace minerals, cortisol, biomarkers for inflammation, and pathogen prevalence. We compared these health metrics between penned and non-penned animals, reproductive and non-reproductive females, and nearby subpopulations. We provide correlative evidence linking reproductive success to trace nutrients but find no evidence for relationships with stress, exposure to pathogens, or biomarkers of inflammation. Based on the health metrics considered, Klinse-Za caribou were generally healthy relative to neighboring subpopulations and repeat capture for penning did not appear to create accumulated health issues. Penned caribou had lower fecal cortisol levels and inflammation markers compared to free-ranging animals. This work provides a baseline assessment of southern mountain caribou health and provides guidance on maternal penning activities in support of caribou recovery.