Population trends of jaguars in a tropical forest in southern Mexico

Abstract

Jaguars are the largest carnivores in the Neotropics with high conservation priority. Population trends of top predators such as jaguars provide valuable information on demography, use of habitats, and individual interactions, which serve to establish conservation and management actions. We studied spatiotemporal population trends of jaguars in a tropical rainforest in the Calakmul Biosphere Reserve (CBR) located in southern Mexico. We used sex-structured open capture–recapture models (OSCR) to estimate jaguar population density related to environmental variables and overlap of individual activity centers to evaluate their spatial interactions. To measure the overlap in the circadian activity, a kernel estimator was used, and intervals of time among pairs of co-occurrences were analyzed to detect spatiotemporal associations between individuals. The population density of jaguars was 1.03 individuals/100 km² (0.59 and 0.44 individuals/100 km² for males and females, respectively). Capture probabilities differed between males and females probably due to differences in their use of human-made trails. Despite temporal variations in population density and individual activity centers, these appeared to have no effect on parameters. Instead, we observed a relationship between (1) distance to roads and detection, (2) net primary productivity and movement, and (3) distance to borders and population density. Temporal circadian overlap showed low values between sexes, although slightly higher values were observed in the rainy seasons. Overall, we found jaguars segregating in space and time. We highlight the importance of the CBR in maintaining continuous suitable habitat and reducing edge effects detrimental to jaguar population density.