MOUNTAIN LION RESEARCH

MOUNTAIN LION HOME RANGES
Mountain lions are captured with foot-hold snares or treed using trained hounds.
Once captured, researchers use a tranquilizer gun to sedate the mountain lion, as shown here.
Mountain lions are captured with foot-hold snares or treed using trained hounds. Once captured, researchers use a tranquilizer gun to sedate the mountain lion, as shown here.

Mountain Lion Home Ranges

Individual mountain lions can occupy large areas of land, and on a private lands landscape this means making use of terrain across multiple ranches. Home range estimates are a way of quantifying the area of land that an animal uses. We estimated home range sizes for mountains lions in 2 ways: Minimum convex polygons (MCPs) and Utilization Distributions (UDs).

MOUNTAIN LION HOME RANGES
Home ranges of four mountain lions in the Davis Mountains.

An MCP incorporates all of the location data points that we have collected for a particular animal by drawing a convex polygon around the outermost points. This often overestimates the area that an animal will actually use, but is a good visual representation of the area that an individual could potentially impact.

MCPs averaged 245 mi2, but varied considerably between individuals. Average subadult MCPs were much larger than adult MCPs, likely because of the inclusion of dispersal or long-range movements that do not necessarily represent increases in actual use. Adult MCPs ranged from 9-400 mi2, and averaged 151 mi2. In general, the MCPs we observed were larger than have been previously recorded in west Texas.

The second way we estimated home range was with 50% and 95% UDs using a program called T-LoCoH. This method factors in both space and time, to determine which areas the animal spends the most time in and effectively describes a “core” area of use (50% UD) as well as an estimate of overall use of space (95% UD).

Adult female MCP and 95% and 50% UD averages were all smaller than the averages for adult males. TXM07, an adult male, had the largest 50% core area (98 mi2), the largest 95% UD (251 mi2), and the largest MCP (387 mi2) when excluding individuals who made long-range or dispersal movements.

Mountain lions use large areas and travel great distances. Our results show that on average a mountain lion may cross 25 or more private ranches. This accentuates the need for a landscape-level approach to management of mountain lions in Texas.