Illegal and unsustainable wild meat use is simplifying vertebrate assemblages across the Neotropics, yet robust information on offtake magnitude and use patterns remains scarce. We used nationwide road-seizure records from Brazil’s Federal Highway Police (Polícia Rodoviária Federal; PRF) from 2017 to 2024, focusing on hunted animals and wild meat intercepted during transport, to quantify the scale and composition of illegal offtake. We then tested whether these enforcement records reproduce expected ecological signals of illegal hunting by examining whether seizure yield and taxonomic composition track state-level defaunation. Across 314 independent events, PRF intercepted ∼9,479 individual animals, totalling ∼9.3 t of biomass, revealing substantial and taxonomically structured pressure on wildlife. The Amazon and Caatinga biomes accounted for the largest shares of events and individuals, respectively. Seized birds dominated numerically in Caatinga, whereas mammals supplied most biomass overall, with reptiles contributing disproportionately in the Amazon and Cerrado–Pantanal biomes. Generalized linear models showed that with increasing defaunation, events involved more individuals but less biomass per seizure, and the mean body mass of seized vertebrates declined. In addition, the proportion of mammals decreased while birds became more prevalent. This convergence with known depletion patterns indicates that road-seizure data can serve as a cost-effective barometer of illegal wild-meat use and its defaunation-linked “downsizing” effect. Targeted responses should pair highway and riverine enforcement, standardize inter-agency reporting (species, counts, biomass, geolocation, product form), and combine access control with community partnerships, livelihood alternatives, and health-risk communication to reduce demand and long-term ecological and public-health impacts.
Tag: defaunation
Exposing illegal hunting and wildlife depletion in the world’s largest tropical country through social media data
Globally, illegal sport hunting can threaten prey populations when unregulated. Due to its covert nature, illegal sport hunting poses challenges for data collection, hindering efforts to understand the full extent of its impacts. We gathered social media data to analyze patterns of illegal sport hunting and wildlife depletion across Brazil. We collected data for 2 years (2018–2020) across 5 Facebook groups containing posts depicting pictures of illegal sport hunting events of native fauna. We described and mapped these hunting events by detailing the number of hunters involved, the number of species, the mean body mass of individuals, and the number and biomass of individuals hunted per unit area, stratified by Brazilian biome. We also examined the effects of defaunation on hunting yield and composition via regression models, rank–abundance curves, and spatial interpolation. We detected 2046 illegal sport hunting posts portraying the hunting of 4658 animals (∼29 t of undressed meat) across all 27 states and 6 natural biomes of Brazil. Of 157 native species targeted by hunters, 19 are currently threatened with extinction. We estimated that 1414 hunters extracted 3251 kg/million km2. Some areas exhibited more pronounced wildlife depletion, in particular the Atlantic Forest and Caatinga biomes. In these areas, there was a shift from large mammals and reptiles to small birds as the main targeted taxa, and biomass extracted per hunting event and mean body mass across all taxonomic groups were lower than in other areas. Our results highlight that illegal sport hunting adds to the pressures of subsistence hunting and the wild meat trade on Brazil’s wildlife populations. Enhanced surveillance efforts are needed to reduce illegal sport hunting levels and to develop well-managed sustainable sport hunting programs. These can support wildlife conservation and offer incentives for local communities to oversee designated sport hunting areas.
Global disparity of camera trap research allocation and defaunation risk of terrestrial mammals
Quantifying and monitoring the risk of defaunation and extinction require assessing and monitoring biodiversity in impacted regions. Camera traps that photograph animals as they pass sensors have revolutionized wildlife assessment and monitoring globally. We conducted a global review of camera trap research on terrestrial mammals over the last two decades. We assessed if the spatial distribution of 3395 camera trap research locations from 2324 studies overlapped areas with high defaunation risk. We used a geospatial distribution modeling approach to predict the spatial allocation of camera trap research on terrestrial mammals and to identify its key correlates. We show that camera trap research over the past two decades has not targeted areas where defaunation risk is highest and that 76.8% of the global research allocation can be attributed to country income, biome, terrestrial mammal richness, and accessibility. The lowest probabilities of camera trap research allocation occurred in low-income countries. The Amazon and Congo Forest basins – two highly biodiverse ecosystems facing unprecedented anthropogenic alteration – received inadequate camera trap research attention. Even within the best covered regions, most of the research (64.2%) was located outside the top 20% areas where defaunation risk was greatest. To monitor terrestrial mammal populations and assess the risk of extinction, more research should be extended to regions with high defaunation risk but have received low camera trap research allocation.