Evaluation of a Cougar Population Estimator Based on Probability Sampling

We used probability sampling of snow tracks which were located from the air as a method of estimating cougar (Felis concolor) numbers. Computer-simulated surveys were conducted on empirical movement data from a known population of cougars to evaluate survey design and the influence of density on the estimator. Estimator precision increased when transects were oriented perpendicular to major drainages, flown 2 days rather than 1 day after a snowfall, and if additional transects were included in each systematic sample. Precision also increased as density of cougars increased. An actual survey flown in an area with 14 cougars estimated 14.2±6.3 (SE) cougars