Data from: Shifting baselines on a tropical forest frontier: extirpations drive declines in local ecological knowledge

The value of local ecological knowledge (LEK) to conservation is increasingly recognised, but LEK is being rapidly lost as indigenous livelihoods change. Biodiversity loss is also a driver of the loss of LEK, but quantitative study is lacking. In our study landscape in SW China, a large proportion of species have been extirpated. Hence, we were interested to understand whether species extirpation might have led to an erosion of LEK and the implications this might have for conservation. So we investigated peoples' ability to name a selection of birds and mammals in their local language from pictures. Age was correlated to frequency of forest visits as a teenager and is likely to be closely correlated to other known drivers of the loss of LEK, such as declining forest dependence. We found men were better at identifying birds overall and that older people were better able to identify birds to the species as compared to group levels (approximately equivalent to genus). The effect of age was also stronger among women. However, after controlling for these factors, species abundance was by far the most important parameter in determining peoples' ability to name birds. People were unable to name any locally extirpated birds at the species level. However, contrary to expectations, people were better able to identify extirpated mammals at the species level than extant ones. However, extirpated mammals tend to be more charismatic species and several respondents indicated they were only familiar with them through TV documentaries. Younger people today cannot experience the sights and sounds of forest animals that their parents grew up with and, consequently, knowledge of these species is passing from cultural memory. We suggest that engaging older members of the community and linking the preservation of LEK to biodiversity conservation may help generate support for conservation.地方生态知识（local ecological knowledge，LEK）对于生物多样性保护的价值正日益得到认可，但随着原住民生计模式的变迁，这类知识正快速流失。生物多样性丧失同样会加速地方生态知识的流失，但目前相关定量研究仍较为匮乏。在我们位于中国西南地区的研究区域内，已有大量物种遭遇本地灭绝。有鉴于此，我们希望探究物种本地灭绝是否会导致地方生态知识的衰退，以及这一现象可能对保护工作产生的影响。为此，我们通过图片向当地居民展示了一批鸟类和哺乳动物样本，测试他们用本地语言说出这些物种名称的能力。研究对象的年龄与其青少年时期前往森林的频率存在相关性，且该因素很可能与其他已知的地方生态知识流失驱动因子（如森林依赖度下降）密切相关。我们发现，整体而言男性在鸟类识别方面表现更优；而相较于类群水平（大致对应分类学中的属级），老年居民能够更准确地识别鸟类的物种名称。年龄对识别能力的影响在女性群体中更为显著。但在控制上述变量后，物种丰度仍是影响居民鸟类命名能力的最关键因素。居民无法说出任何本地灭绝鸟类的物种名称。但与预期相悖的是，居民在物种水平上识别本地灭绝哺乳动物的能力，反而强于现存哺乳动物。但这类本地灭绝的哺乳动物多为极具标志性魅力的物种，部分受访者表示，他们仅通过电视纪录片了解过这些动物。如今的年轻群体无法体验到父辈童年时接触的森林动物的视听景象，因此这类物种的相关知识正从文化记忆中逐渐消逝。我们建议，通过吸引社区老年群体参与，并将地方生态知识的保护与生物多样性保护工作相结合，可为保护事业争取更多支持。