By Víctor H. Luja, 24th May 2022
The jaguar Panthera onca is the largest felid in the Americas, found from northern Mexico to Argentina. However, its distribution is not continuous. Jaguar subpopulations are highly fragmented, and about 60% of their natural habitat has been lost as a result of human activities such as agricultural and infrastructure expansion. People are also responsible for hunting jaguars—in retaliation for attacks on livestock or for illegal sale of body parts—as well as their prey. This has led them to be categorized as Near Threatened on the IUCN Red List, and at risk of extinction under Mexican jurisdiction.
Jaguar in a mangrove forest in Nayarit, Mexico. Photo: Víctor H. Luja
Most jaguar subpopulations in Mexico face serious habitat fragmentation problems, except for the subpopulations of Calakmul in Campeche, and some areas of the Selva Lacandona in Chiapas, where there are still large tracts of continuous forests. It is necessary to understand the dynamics of jaguars and their prey in highly fragmented areas, to propose adequate measures for their conservation. We sought to analyse the population dynamics of jaguars, the diversity and abundance of their prey, and the patterns of habitat loss in Nayarit, western Mexico. The Mexican Pacific is considered an important zone for jaguar conservation. This area connects the populations of the central Pacific (Jalisco and Michoacán) with those of the North Pacific (Sinaloa and Sonora), including the individuals that cross the border into the United States.
Pictures of jaguar, white-tailed deer, collared peccari and coatimundi obtained by camera traps during this study. Photos: Víctor H. Luja
In 2019 and 2020 we used camera traps to determine the number of individuals, age classes and sex ratio, occupancy, relative abundance and density of jaguars. We also determined the relative abundance of their prey and estimated the rate of land-use change using a geographical information system. We involved local community members during the placement and monitoring of camera traps, to build capacity and encourage their active participation in conservation.
We found a subpopulation of resident jaguars (five adult females, two adult males and one cub). These density of this subpopulation is comparable with densities recorded in well-preserved areas of continuous forests such as El Edén in Quintana Roo. We also found substantial potential prey for the jaguar, including the white-tailed deer, collared peccary, coati, raccoo and birds, and reptiles.
Left: Aerial view of the landscape in the study area. Agricultural land and shrimp farms replace mangroves and jungles. Photos: Por el Planeta. Right: Diana Guzmán, María Zamudio and Alberto Ponce (local fishermen) deploying camera traps. Photo: Víctor H. Luja
However, the natural habitat of these jaguars is rapidly disappearing. In just 20 years, the coverage of agricultural land increased from 39 to 50%, and mangrove cover decreased from 35 to 26%. This implies an imminent risk for the permanence of jaguars and their prey. Transformation and loss of habitat has been identified as the main cause of biodiversity loss, and Mexican Pacific coastal region continues to be threatened by these pressures.
Our project has focused on working with the local community, to explain the importance of protecting and understanding mangrove systems and their relevance for the subsistence of both people and jaguars. We organized several environmental education activities such as talks and photographic exhibitions, and published a children’s book based on our findings. Throughout our work in each study area, we involve key stakeholders and community members. We also created the Facebook page Jaguares Sin Protección, which has become a communication channel about our results and generated interaction and engagement with people from all over the region.
Environmental education activities in Boca del Asadero, San Blas, Nayarit, Mexico. Photos: Victor H: Luja
The article Jaguars in the matrix: population data, relative abundance of prey, and land cover change changes of a fragmented landscape in western Mexico is available in Oryx—The International Journal of Conservation.
