Demographic assessment using physical and genetic sampling finds stable polar bear subpopulation in Gulf of Boothia, Canada

Abstract

AbstractKnowledge of long‐term demographic trends is important for managing large carnivore populations under changing environmental conditions, management objectives, and human values. From 2015 to 2017, we biopsy‐sampled polar bears (Ursus maritimus) in the Gulf of Boothia (GB) subpopulation to genetically identify individuals. This less‐invasive sampling method was more compatible with stakeholder values than chemical immobilization. We analyzed the biopsy data together with live‐capture study data (1998–2000), opportunistically collected live‐capture data (1976–1997), and harvest recovery data (1976–2017). From 2015 to 2017, the mean model‐averaged abundance estimate was 1,525 bears (SE = 294), similar to both the 1998–2000 estimate from the current analysis (1,610 ± 266) and previously published estimate (1,592 ± 361). Total survival from 2015–2017 varied by sex and age class, with higher estimates for adult females (0.95, 95% CI [0.81, 0.99]) than adult males (0.85, 95% CI [0.74, 0.92]). Mean number of yearlings per adult female was 0.36, 95% CI [0.26, 0.47], suggesting healthy reproduction. Body condition improved between 1998–2000 and 2015–2017. Our findings suggest the GB subpopulation is currently productive and stable. Forecasts of continued sea‐ice loss and environmental change due to climate warming emphasize the need for ongoing monitoring of this subpopulation.