Authors: Romero-Muñoz, Alfredo; Bleyhl, Benjamin ;Camino, Micaela ;De Angelo, Carlos ;Decarre, Julieta;Giordano, Anthony J.;Maffei, Leonardo;Nanni, Sofía ;Noss, Andrew ;Nuñez-Regueiro, Mauricio M. ;

Large carnivore populations are declining globally due to the impacts of multiple threats, particularly habitat destruction and direct persecution. Understanding the relative contributions of different threats to population declines is important to set effective conservation interventions, but for most species, this remains poorly understood. Here, we assess the individual and combined impacts of habitat destruction and persecution on jaguar and puma populations across the 1.1 million km2 South American Gran Chaco. We reconstructed species-specific habitat suitability, as well as the spatial footprints of each threat for the period 1985-2020. We then used these data in spatially explicit, individual-based modelling frameworks to analyze population dynamics under different threats. We found that persecution contributed more strongly to population declines of both jaguar and puma than habitat destruction. Furthermore, where both threats interacted, declines were much stronger than for any single threat. Our analyses also uncovered where remaining population sources and sinks for each species are in the Chaco. These results highlight the key areas where threat-specific interventions could effectively contribute to conserving large predator populations across the region. Our study underlines the urgent need for considering multiple threats together to design and implement more effective conservation strategies.