RESUMO
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 (â¼29 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.
Exposición de la caza ilegal y la reducción de fauna en el país tropical más grande del mundo por medio de datos de las redes sociales Resumen En todo el mundo, la caza recreativa ilegal puede amenazar a las poblaciones de presas cuando no está regulada. Debido a su naturaleza encubierta, la caza recreativa ilegal plantea dificultades para la recopilación de datos, lo que dificulta la comprensión de su impacto. Recopilamos datos de redes sociales para analizar los patrones de caza recreativa ilegal y agotamiento de la vida silvestre en todo Brasil. Recopilamos datos durante 2 años (20182020) a través de cinco grupos de Facebook que contenían publicaciones que mostraban imágenes de eventos de caza recreativa ilegal de fauna nativa. Describimos y mapeamos estos eventos de caza detallando el número de cazadores involucrados, el número de especies, la masa corporal media de los individuos y el número y la biomasa de los individuos cazados por unidad de área, estratificados por bioma brasileño. También examinamos los efectos de la deforestación en el rendimiento y la composición de la caza mediante modelos de regresión, curvas de abundancia e interpolación espacial. Detectamos 2,046 puestos de caza recreativa ilegal que mostraban la caza de 4,658 animales (â¼29 t de carne sin desollar) en los 27 estados y 6 biomas naturales de Brasil. De las 157 especies autóctonas objetivo de los cazadores, 18 están actualmente en peligro de extinción. Se calcula que 1,414 cazadores extrajeron 3,251 kg/millón de km2. Algunas zonas mostraron una defaunación más pronunciada, en particular los biomas de la Mata Atlántica y la Caatinga. En estas áreas, se produjo un cambio de grandes mamíferos y reptiles a pequeñas aves como principales taxones objetivo, y la biomasa extraída por evento de caza y la masa corporal media en todos los grupos taxonómicos fueron menores que en otras áreas. Nuestros resultados ponen de manifiesto que la caza recreativa ilegal se suma a las presiones de la caza de subsistencia y el comercio de carne salvaje sobre las poblaciones de fauna de Brasil. Es necesario intensificar los esfuerzos de vigilancia para reducir los niveles de caza recreativa ilegal y desarrollar programas de caza recreativa sostenibles y bien gestionados. Estos programas pueden contribuir a la conservación de la fauna y ofrecer incentivos a las comunidades locales para que supervisen las zonas designadas para la caza recreativa.
Assuntos
Animais Selvagens , Conservação dos Recursos Naturais , Caça , Mídias Sociais , Conservação dos Recursos Naturais/legislação & jurisprudência , Brasil , Animais , Esportes/legislação & jurisprudência , HumanosRESUMO
Although most often considered independently, subsistence hunting, domestic trade, and international trade as components of illegal wildlife use (IWU) may be spatially correlated. Understanding how and where subsistence and commercial uses may co-occur has important implications for the design and implementation of effective conservation actions. We analyzed patterns in the joint geographical distribution of illegal commercial and subsistence use of multiple wildlife species in Venezuela and evaluated whether available data were sufficient to provide accurate estimates of the magnitude, scope, and detectability of IWU. We compiled records of illegal subsistence hunting and trade from several sources and fitted a random-forest classification model to predict the spatial distribution of IWUs. From 1969 to 2014, 404 species and 8,340,921 specimens were involved in IWU, for a mean extraction rate of 185,354 individuals/year. Birds were the most speciose group involved (248 spp.), but reptiles had the highest extraction rates (126,414 individuals/year vs. 3,133 individuals/year for birds). Eighty-eight percent of international trade records spatially overlapped with domestic trade, especially in the north and along the coast but also in western inland areas. The distribution of domestic trade was broadly distributed along roads, suggesting that domestic trade does not depend on large markets in cities. Seventeen percent of domestic trade records overlapped with subsistence hunting, but the spatial distribution of this overlap covered a much larger area than between commercial uses. Domestic trade seems to respond to demand from rural more than urban communities. Our approach will be useful for understanding how IWU works at national scales in other parts of the world.