The loss of prey base may drive the jaguar (Panthera onca) toward extinction in the Atlantic Forest of South America

Jaguar ( Panthera onca ) is critically endangered in the Atlantic Forest hotspot. Concerned with its imminent extinction, this study combined information on jaguar diet and feeding habits with the most extensive standardized camera-trap survey of jaguar prey species ever conducted in the biome. We aimed to estimate local prey abundance and biomass in nine protected areas, comparing a high-abundance area in the Green Corridor to lower-abundance or jaguar-free areas in the Coastal Atlantic Forest. Additionally, we evaluated the influence of human pressures and environmental variables on prey availability. A systematic literature review was conducted to identify the prey items in the jaguar diet. Camera traps were deployed in a systematic grid. We estimated the local abundance of 14 key prey species using detection/non-detection data in a multi-region community modelling approach. Results showed that jaguar diets are dominated by large-bodied prey, particularly Tayassuidae and Cervidae. Estimated prey abundances (mean = 27.3 individuals) and biomass (mean = 638 kg) were highest in the Green Corridor - and lowest in Coastal regions (abundance mean ranging from 1.3 to 10 individuals and mean biomass ranging from 8.2 to 492 kg by PA) where jaguars are absent or occur at very low densities. The low abundance and biomass of prey species was explained by human presence, since prey was more abundant in areas with a high cost of human access and less abundant where human access was favored. Long-term conservation of jaguars in the Atlantic Forest depends on restoring prey populations through participatory governance and adaptive management that bridges ecological and social dimensions of conservation.