CONICET | Buscador de Institutos y Recursos Humanos

The Upper Paraná Atlantic Forest (UPAF) is among the most endangered eco-regions of the world because of its high levels of fragmentation and degradation. In this area located in the border among Argentina, Brazil and Paraguay, persists the southernmost population of jaguars (Panthera onca) of the world. My aims were to explore the landscape level factors that are affecting jaguar persistence in this region and to develop a spatial model for predicting the conditions of its habitat from a management perspective in the UPAF. I used presence records of jaguars collected through a participatory network of volunteers distributed along the eco-region. I combined these records with pseudo-absences to be used in generalized linear models. I used the information-theoretic approach to test different hypotheses related with the conditions that determine jaguar presence. I selected two general models representing the two main evaluated hypotheses: 1) landscape-conditions model; and 2) direct human pressures model. These models were used independently to develop a two-dimensional spatial model of jaguar habitat suitability. Jaguar persistence was favored not only by the presence of native forest at present but also by the historical presence of forest (30 years ago), and negatively affected by human land uses. Direct human pressures also had an important effect on jaguars, with a positive effect of protection and negative effects of human accessibility and historical human population density. The two-dimensional model showed that less than 8% (~20,670 km2) of the analyzed landscape presented suitable conditions to be considered as potential core areas for jaguars. Barrier areas (unsuitable) represented 60.0% of the study area, 3.3% were potential refuges (areas that need restoration: low human pressures but poor landscape conditions), and 15.1% were potential sinks (poor landscape conditions and relatively high human pressures). From the management perspective, the most important areas detected by the model were the 32,563 km2 (11.8%) of potential attractive-sink areas that presented acceptable landscape conditions for jaguars but high direct human pressures (i.e. potential ecological traps for this species). This analysis allowed the description of the most important factors affecting jaguars at an eco-regional scale (e.g. the historical conditions of the landscape). Additionally, it constituted a useful management tool for validating conservation strategies developed for jaguars and the UPAF.

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