An improved understanding of ungulate population dynamics using count data: Insights from western Montana.

摘要: Understanding the dynamics of ungulate populations is critical given their ecological and economic importance. In particular, ability to evaluate evidence for potential drivers variation in population trajectories important informed management. However, use age ratio data (e.g., juveniles:adult females) as an index hindered by a lack statistical power difficult interpretation. Here, we show that model based on count, classification harvest can dramatically improve understanding by: 1) providing estimates vital rates per capita recruitment growth) are easier interpret more useful managers than ratios 2) increasing assess sources key rates. We used time series elk (Cervus canadensis) spring count (2004 2016) fall from hunting districts western Montana construct estimate association between environmental covariates indices predator abundance calves. Our results suggest were negatively associated with cold wet springs, severe winters, positively summer precipitation. contrast, analysis raw failed detect these relationships. approach provided region-wide mean rate (mean = 0.25, 90% CI 0.21, 0.29), temporal hunting-district-specific (minimum 0.09; [0.07, 0.11], maximum 0.43; [0.38, 0.48]), annual growth 0.83; [0.78, 0.87], 1.20; [1.11, 1.29]). recommend using routinely collected modeling rather interpreting estimated substantial improvement dynamics.