Hunting pressure modulates the composition and size structure of terrestrial and arboreal vertebrates in Amazonian forests

Abstract Overhunting is a leading contemporary driver of tropical forest wildlife loss. The absence or extremely low densities large-bodied vertebrates disrupts plant-animal mutualisms and consequently degrades key ecosystem services. Understanding patterns defaunation therefore crucial given that most forests worldwide are now “half-empty”. Here we investigate changes in vertebrate community composition size structure along gradient marked anthropogenic hunting pressure the Médio Juruá region western Brazilian Amazonia. Using novel camera trapping grid design deployed both understorey canopy, estimated aggregate biomass several functional groups terrestrial arboreal species at 28 sites gradient. Generalized linear models (GLMs) identified as important for game, terrestrial, species, well nocturnal rodents, frugivores, granivores. Local affected shown by GLM ordination analyses. fauna changed heavily hunted areas due to population declines apparent compensatory increases rodents. Our study shows markedly altered even remote but settled continuous primary forest. Depletion frugivore granivore populations, concomitant density-compensation seed predators, likely affect regeneration persistently overhunted forests. These findings contribute better understanding how cascading effects induced historical operate, informing management policy peri-urban, rural wilderness areas.