Proceedings of the Seventh Mountain Lion Workshop

IMPACT OF EDGE HABITAT ON HOME RANGE SIZE IN PUMAS
JOHN W. LAUNDRÉ, Instituto de Ecología, A.C. Apartado Postal 632, 34100 Durango, Dgo.,
México, email: launjohn@prodigy.net.mx
LUCINA HERNÁNDEZ, Instituto de Ecología, A.C. Apartado Postal 632, 34100 Durango,
Dgo., México, email: lucina@sequia.edu.mx
Abstract: In the previous workshop in San Antonio, researchers from Wyoming reported that
pumas from two areas with different amounts of fragmentation still had home range areas that
contained equal amounts of periphery (= edge). In the same workshop, we reported that edge
habitat was critical for successful hunting of deer by pumas. These two results indicate that the
amount of edge habitat in an area may be an important factor in determining home range size of
pumas. We tested this hypothesis with data we have on home ranges of pumas in southern
Idaho/northwestern Utah. The study area is highly fragmented into forest patches and sagebrush
open areas. We tested three predictions: 1) the amount of edge habitat in the home ranges of
pumas would be similar, regardless of the size of the home range, 2) the percent of edge would
be negatively related to home range size, and 3) there would be more edge habitat within home
range boundaries than in general areas of similar size. We tested these predictions by overlaying
telemetry locations on habitat maps of the area, determining the home range boundaries with the
minimum convex polygon method and then estimating the amount of forest edge (km 2 ) that
occurred in each home range. The analysis was conducted with standard GIS software and we
had 20 pumas where the home range was adequately determined (> 30 relocations). Home
range size varied from 38 to 120 km 2 . However, 14 (70%) of the home ranges were between 38
to 105 km 2 . The amount of edge habitat within all the home ranges varied from 13 to 35 km 2 .
Within the 14 smaller home ranges, the amount of edge varied from 13 to 20 km 2 . The percent
of edge within home ranges was negatively correlated with home range size. The amount of
edge within the home range boundaries was significantly greater (F = 15.05, P < 0.001) than
general areas of similar size. We concluded that the amount of edge within an area was
influencing the size of home ranges. We proposed that pumas needed a certain minimum
amount of edge (hunting habitat) to successfully hunt their prey and that the amount of
“catchable” prey was more important than just general prey abundance.
PROCEEDINGS OF THE SEVENTH MOUNTAIN LION WORKSHOP
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