Proceedings of the Seventh Mountain Lion Workshop

ECOLOGY OF SYMPATRIC PUMAS AND JAGUARS IN NORTHWESTERN
MEXICO
CARLOS A. LOPEZ GONZALEZ, Universidad Autonoma de Queretaro, Cerro de las
Campanas s/n, Mexico, email: Cats4mex@aol.com
SAMIA E. CARRILLO PERCASTEGUI, Northern Jaguar Project, 2114 W. Grant Rd. #121,
Tucson, AZ 85745, USA, email: Cats4mex@aol.com
Abstract: Pumas (Puma concolor) are usually considered subordinate species where jaguars
(Panthera onca) are present. Most of the current information on resource partitioning by these
two species comes from tropical sites. Out study area is located in the limits of the tropical realm
and consequently could be characterized as puma habitat. Our objectives were to describe the
ecology of both large felids in an area located 135 s. of the United States border, in the state of
Sonora, Mexico. From July 1999 to December 2002 using a suite of methodologies (cameratraps,
radio-telemetry, scat, track and prey surveys), we surveyed an area ≈1000 km². The study
area is a matrix of oak-woodland, tropical thornscrub, and upper sonoran desert; ranging in
elevation from 200 to 1200 m. The main economic activity within the region is ranching. We
determined through radio-telemetry a density of 3 pumas/100 km², and through camera-trap
surveys a density of 1.4±0.4 jaguars/100 km². Camera-trap capture rates are three times higher
for pumas than jaguars. Both species are feeding on white-tailed deer and to a lesser extent on
livestock. Pumas are a cathemeral species whereas jaguars are nocturnal-crepuscular. Jaguars are
using oak woodlands more than expected by chance, where pumas are using habitats according
to availability. The number of pumas present may be an artifact of less prosecution by cowboys
(only 1 puma killed since 1999), where jaguars are constantly prosecuted as they are perceived as
liable of most livestock depredations (22 jaguars killed since 1999). During 2002 we began a
program to help local ranchers on maintaining infrastructure, and apparent result has been less
pressure on the jaguar population within the area.
PROCEEDINGS OF THE SEVENTH MOUNTAIN LION WORKSHOP
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