Photo by Ben Masters

Estimating Abundance of Black Bears and Mountain Lions Using Camera Surveys in West Texas

Jamie Cooper, Patricia Moody Harveson, Dana Karelus, and Louis A. Harveson

Large carnivores act as keystone species as they play an essential role in maintaining the balance of ecosystems. Estimates of large carnivore population sizes are therefore useful not only for their management, but also for management of their prey species. Difficulties arise when studying these carnivores, as they are often elusive, few in number, and have large ranges, but ever-evolving methods using remote cameras and spatial data may provide practical options for obtaining population estimates.

Limited research on the population estimates of large carnivores in West Texas has been published; thus, our objective was to evaluate the use of camera surveys to estimate abundance of black bears (Ursus americanus) and mountain lions (Puma concolor) in the Davis Mountains. We established a 342-km2 grid with 36 remote cameras to survey for these species. We placed cameras at baited sites on likely travel corridors, such as mountain saddles and game trails. We surveyed for two 12-week periods (summer 2018 and spring 2019) and collected approximately 835,000 photographs. In summer 2018, we collected 9 independent photos of mountain lions and 25 independent photos of bears. In spring 2019, we collected 39 and 21 independent photos of mountain lions and black bears, respectively.

We will use these photos to estimate abundance and evaluate the use of camera surveys for monitoring large carnivore populations in West Texas. These results will be useful for conservation and management specialists interested in non-invasive techniques for acquiring population estimates.

Funding source: Welder Wildlife Foundation, Horizon Foundation, Summerlee Foundation, and study site access from The Nature Conservancy.