School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom.
PPG Ecologia e Conservação da Biodiversidade, Universidade Estadual de Santa Cruz, Ilhéus, Brazil.
PLoS One. 2017 Oct 17;12(10):e0186653. doi: 10.1371/journal.pone.0186653. eCollection 2017.
The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not "emptied" the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of wildlife for food, thereby providing a conservative assessment of game depletion. Given this 'best-case' camera trap and interview-based evidence for hunting depletion, regions with higher human population densities, external trade in wildlife and limited access to alternative protein will likely exhibit more severe depletion.
人类社区居住的热带森林中，陆生脊椎动物种群的减少程度一直是一个激烈争论的话题，这个话题对保护具有重要意义。保护生态学家和从业者在以社区为基础的生计性狩猎是否与热带森林猎物物种的生态功能种群兼容的问题上存在分歧。为了量化人类社区周围森林脊椎动物的减少范围，我们总共部署了 383 个相机陷阱站和 78 次定量访谈，对中亚马孙地区梅迪奥茹鲁阿和乌图马努地区 60 个半自给社区控制的周边社区进行了调查，总面积超过 320 万公顷。我们的结果与之前的证据基本一致，即狩猎大型脊椎动物会减少定居点附近的野生动物数量，以至于只有在狩猎频率较低的定居点之外才能发现它们。相机陷阱数据表明，包括低地貘在内的少数几种对收获敏感的物种，要么被人类社区排斥，要么被它们消耗殆尽。在靠近社区的受干扰地区，夜间和白天活动的物种被检测到的频率相对较高，但个别物种不一定改变它们的活动模式。所有物种的个体生物量在城市地区的更广泛周边地区而不是社区中受到抑制。访谈数据表明，物种特征，特别是群体大小和体重，介导了这些关系。有经验的消息人士报告说，体型较大、群体较大的物种在远离社区的地方被检测到。在我们的研究区域，历史悠久的社区并没有“使周围的森林变得荒芜”。由于替代水生蛋白质的丰富来源，人口密度低和狩猎收获低，这表明这些社区代表了可持续狩猎野生动物作为食物的最佳情况，从而对猎物减少提供了保守评估。鉴于这种基于最佳情况的相机陷阱和访谈证据表明狩猎减少，人口密度较高、野生动物外部贸易和替代蛋白质获取途径有限的地区可能会出现更严重的减少。
