Genetic monitoring of Scandinavian brown bear effective population size and immigration
Résumé
We used microsatellite marker data taken from Scandinavian brown bear (Ursus arctos) tissue samples collected by hunters and biologists to estimate population genetic parameters important for bear management. Specifically, we show evidence of a small effective population size (N-e=44.8; 95% CI: 30.9 to 73.2) and low rates of immigration ((m) over cap = 0.01; 95% CI: 0.00 to 0.05) into the brown bear population along the southern edge of their range in Scandinavia. The ratio of genetic effective size to population size is approximately 0.06-0.14, which falls within the range of values found in previous studies of brown bears. The large confidence intervals around the immigration estimate reflect considerable uncertainty. Nonetheless, these values deserve attention because they are near thresholds of short-term management concern and worthy of long-term monitoring. If the genetic effective size remains this small and immigration remains low, then this population could be subject to the loss of fitness as a consequence of inbreeding effects.