Biological and environmental correlates of cougar (Puma concolor) survival in west central Alberta

Managing large carnivores benefits from understanding their vital rates, including survival. For cougars (Puma concolor), the hazards relevant to survival across the landscape are poorly understood. The risks that landscape features present can change temporally, increasing survival in one season while creating mortality risk in another. Between 2016 and 2021, 80 cougars were radio-collared and tracked in west central Alberta, Canada, for a total of 1082 cougar months with a mean monitoring time of 13.5 months/individual. We documented 37 deaths, determined causes of mortality, generated survival estimates using Kaplan-Meier models by sex and age class annually and for two seasons (i.e., warm and cold), and investigated factors affecting survival using Cox proportional hazard models. Humans were responsible for 29 of the 37 documented mortalities, including harvest, removal of problem individuals, landowner removals, incidental trapping, and vehicle collisions, with harvest representing the largest single source of mortality (16/37 deaths) for both sexes. However, we were unable to detect a difference in survival estimates between sexes or age classes and found no evidence of a male-biased harvest. Mean annual survival was 0.60 (95% CI: 0.50-0.72) and varied seasonally with lower survival in the cold season (0.62, 95% CI: 0.52-0.74) than the warm season (0.96, 95% CI: 0.92-1.00). Using Cox proportional hazards models (Andersen-Gill), model selection identified a best-supported mixed model combining biological, environmental, and anthropogenic features: season, proximity to residences, proximity to secondary roads, linear-feature crossing rate, and step length.