You are here

Re-Estimating the Abundance of the Davis Strait Polar Bear Sub-Population via Genetic Mark-Recapture Sampling

The Davis Strait (DS) polar bear subpopulation is shared by Nunavut, Quebec (Nunavik), and Newfoundland and Labrador (Nunatsiavut). The population was first inventoried in the 1970s but likely underestimated because of poor aerial coverage. A comprehensive population study was conducted between 2005-2007 which found the abundance to be approximately 2,158 bears. In recent years, Inuit have indicated that large numbers of bears are creating public safety concerns especially for people going out on the land. Inuit believe that the bears are negatively impacting other wildlife by eating large numbers of young seals, and eggs in bird colonies. There is some uncertainty surrounding the current status of the DS population, in part of known changes to the sea-ice habitat, but it is believed that the population is either stable or has likely been increasing since the last inventory was completed in 2007. Given these factors, the co-management partners were all supporting a new research study between 2017 and 2018. A new 2-year research project was initiated in 2017 to provide updated information on the abundance of bears in DS. This mark-recapture study differs from the previous studies that relied on chemical immobilization of all bears for capture and marking. This study does not involve capture of bears but instead utilizes DNA extracted from tissue samples obtained using biopsy darts to uniquely identify individuals. The sub-population abundance estimate and status will be assessed by means of genetic mark-recapture.

Between 4 August and 11 October, a total of 350 hours between 2 aircraft was spent searching for polar bears in the study area. We encountered 639 bears of various sex and age classes, of which 530 were successfully biopsied. The rate of sampling averaged 2.2 bears per hour of search time. The number of bears encountered during the fall of 2017 was equivalent to approximately 29.2% of the previous 2005-2007 mark-recapture population estimate currently used for harvest management. Litter sizes for cubs of the year and yearlings were similar with 1.5 for each. Until genetic results are available it is impossible to discern how many different individual bears were encountered, or how many recaptures occurred.