Sean C P Coogan, University of Alberta
The first provincial DNA population survey of grizzly bears (Ursus arctos) was undertaken in 2004 in Bear Management Area (BMA) 3 (“Yellowhead” study area). Spatial mark recapture (SECR) analysis of the 2004 genetic data produced a population estimate of 36 grizzly bears (95% CI: 28.6-45.3). Ten years later, a second DNA population survey in 2014 produced a population estimate using the same methods of 71.3 grizzly bears (CI: 53.9-94.2). The change in population over the 10-year period equates to an annual rate of increase of 7%, which is higher than typically seen in North American interior grizzly bear populations. The reasons for the increase are unclear, and require further analysis to determine whether current and past management practices contributed. Specifically, road density threshold approaches to landscape management in combination with changing landscape conditions (both natural and anthropogenic disturbance) are factors hypothesized to have contributed to the increase. These factors could have affected the BMA 3 grizzly bear population through both top-down (i.e. mortality) and bottom-up (i.e. nutritional resources contributing to population growth) regulation. Furthermore, recent research suggests that grizzly bears translocated from other BMAs (i.e. “problem” bears) have contributed to this increase. Thus, the factors contributing to the grizzly bear population increase in BMA 3 are complex. This provides an unprecedented opportunity to examine how such factors influence local grizzly bear population dynamics and highlights the power and necessity of long-term grizzly bear population monitoring.