Developing a management tool to estimate unmarked puma ( Puma concolor) populations with a remote camera array

Puma (Puma concolor) ecological research, puma management, and puma conservation require a technique to efficiently estimate puma populations. Adequate population estimates for pumas are difficult to produce due to natural history characteristics of the species. Remote camera arrays present a promising new tool for surveying cryptic mammals, but techniques for estimating population levels of unmarked animals or species that are difficult to individually identify in photographs are needed. Our goal was to develop techniques to (1) determine the camera effort needed to detect resident pumas with 95% certainty and (2) estimate puma population density for unmarked pumas with a remote camera array. An array of 25 cameras spread 2 km apart in a square grid covering an area of 100 km2 was used to detect 5 individually marked pumas. Photographic captures and GPS collar data for 1 male and 1 female puma were used to calculate the mean number of camera days required to reach a detection probability of 95% for a single resident puma within a camera array of one to 25 cameras. These photographic capture rates were used to calculate population density estimates based on how many cameras were used in the array, how many camera nights were included in the survey, and how many total puma photos were captured. Population estimates were calculated based on puma photos from 71 continuous running days of a 25 camera array from November 11, 2009 to January 20, 2010 and included a total of 1188 camera nights. A mark-resight population estimate yielded a puma density of 2.1 (1.7-4.4) puma/100 km2. Our population estimate based on photo capture rate yielded 1.8 (1.4-2.2) puma/100 km 2 and fell within the 95% confidence interval of the mark-resight estimate. These results suggest that remote camera arrays can be used to accurately estimate resident puma population density based on the number of unmarked puma photos captured.