|Rodrigo Nunez Perez|
|Jaguar (Panthera onca) and Mountain Lions (Puma concolor) censusing by camera trapping in the Chamela-Cuixmala Biosphere Reserve, Jalisco, Mexico|
|Location: Chamela-Cuixmala Biosphere Reserve, Mexico|
|Abstract: In January 1995, we initiated a project to investigate the ecology of jaguar and mountain lion in and around the Chamela-Cuixmala Biosphere Reserve at Jalisco coast, Mexico. While the Reserve measures 130 km2, telemetry covers an additional 200 km2 outside of the Reserve. Tropical dry forest is the main vegetation. We used radio-telemetry to analyze movements, home range, activity time, habitat selection, and food habits of both sympatric cats. On a larger scale, cameras can be used to census jaguars and pumas throughout their range, and is a non-invasive technique. Accurate estimates of carnivores are essential for their conservation. Cameras have shown great results for estimating numbers of jaguars in Belize and tigers in Asia, the use of camera traps and radio-telemetry have not been combined for a large carnivore. Combining an existing radio-telemetry study with estimates of populations by cameras could advance the camera-trap technique considerably. Telemetry could test the reliability of identifying a wild jaguar by its spots on a photo, or identifying a mountain lion by scars and inside legs spots. By continuous monitoring, we will learn how frequently cats are photographed when they enter the immediate area of a camera. Estimates of a population will be made through standard capture-recapture statistical methods through density calculations derived from camera trapping data, telemetry and through models that combine the two methods.|
Project Update: January 2006
The central objective of this study is to understand the interactions that exist between jaguars and pumas and the effect these have on the conservation of both species. Through this study, we have determined that the Chamela-Cuixmala Biosphere Reserve (CCBR), in spite of being small in extension (13,142 ha.), favors the conservation and reproduction of jaguars, pumas and other feline species in the region. Radio telemetry techniques have been fundamental in determining the behavior of felines. Nevertheless, new questions have arisen, and relatively new techniques such as automatic cameras (Karanth and Nichols 1998), have enabled us to determine other aspects of the ecology of jaguars pumas prey. In recent years, the jaguar has been importance high-priority species for conservation in Mexico, and the CCBR offered an opportunity to apply and evaluate techniques for estimating population size of jaguars and pumas.
In 2005, we identified 10 adult jaguars and 1 cub (about 2-4 months old) and 5 pumas. Two jaguars were radio monitored. Home range of the male radio-tagged jaguar was 58.8 km2 and the females was 16.4 m2. 16 automatic cameras were set-up at different sites in the reserve. Of the 16 camera sites, 2 sites photographed only jaguars and 3 sites photographed only pumas, while at 2 sites no large cats were photographed. Based on the capture rate of automatic cameras, Jaguar density was estimated at 8.3 ind. / km2 and puma density at 4.3 ind./km2.
Automatic cameras were set-up at 16 stations during the dry season. We conducted camera surveys on 12 occasions, each lasting 5 days. Cameras were placed along dry stream-beds, which the cats use as pathways, increasing the chances of photographing a large cat. A total of 320 photographs were taken, with 285 photographs of mammals. The most common mammal recorded was the White-tailed Deer followed by ocelots. There were 33 Jaguar photographs, and 12 Puma photographs. Overall, we identified 11 individual jaguars (including one cub) and 5 pumas.
A female with a cub was photographed in the main trapping sites, therefore capture of jaguars and pumas was suspended and no cats were captured during the study. Three previously radio collared jaguars, two males and one female were monitored via radio telemetry, but only two were available during the automatic camera survey. One jaguar transmitter failed and we lost the signal. This same jaguar was photographed by the automatic cameras. Due to the absence of radio collared felines, the comparisons of photographic recapture versus radio telemetry will be done next year.
The home ranges in our results confirm that male jaguars use a larger area than female, and in this case home range overlap is small, only 2% for the male and 7% for the female. Camera trapping results show that there are at least 8 adult large cats using partially the same territory, the center of the CCBR. Results show a high jaguar density. Little data exist on neotropical pumas, but density reported in this study is similar to the mean calculated by Gomes (1993), 1 puma per 25 km2. Our results reflect the positive effects of more than ten years of relative protection. The estimate of 22 jaguars and 9 pumas for the CCBR and surroundings is ideal. We expect that outside CCBR prey and cat abundance is 30-40% lower. CCBR is an important refuge for wildlife in the zone and may be playing role as a source spot to maintain the presence of cats and preys beyond CCBR.