Data from: The distribution and numbers of cheetah (Acinonyx jubatus) in southern Africa

Assessing the numbers and distribution of threatened species is a central challenge in conservation, often made difficult because the species of concern are rare and elusive. For some predators, this may be compounded by their being sparsely distributed over large areas. Such is the case with the cheetah Acinonyx jubatus. The IUCN Red List process solicits comments, is democratic, transparent, widely-used, and has recently assessed the species. Here, we present additional methods to that process and provide quantitative approaches that may afford greater detail and a benchmark against which to compare future assessments. The cheetah poses challenges, but also affords unique opportunities. It is photogenic, allowing the compilation of thousands of crowd-sourced data. It is also persecuted for killing livestock, enabling estimation of local population densities from the numbers persecuted. Documented instances of persecution in areas with known human and livestock density mean that these data can provide an estimate of where the species may or may not occur in areas without observational data. Compilations of extensive telemetry data coupled with nearly 20,000 additional observations from 39 sources show that free-ranging cheetahs were present across approximately 789,700 km2 of Namibia, Botswana, South Africa, and Zimbabwe (56%, 22%, 12% and 10% respectively) from 2010 to 2016, with an estimated adult population of 3,577 animals. We identified a further 742,800 km2 of potential cheetah habitat within the study region with low human and livestock densities, where another ∼3,250 cheetahs may occur. Unlike many previous estimates, we make the data available and provide explicit information on exactly where cheetahs occur, or are unlikely to occur. We stress the value of gathering data from public sources though these data were mostly from well-visited protected areas. There is a contiguous, transboundary population of cheetah in southern Africa, known to be the largest in the world. We suggest that this population is more threatened than believed due to the concentration of about 55% of free-ranging individuals in two ecoregions. This area overlaps with commercial farmland with high persecution risk; adult cheetahs were removed at the rate of 0.3 individuals per 100 km2 per year. Our population estimate for confirmed cheetah presence areas is 11% lower than the IUCN’s current assessment for the same region, lending additional support to the recent call for the up-listing of this species from vulnerable to endangered status.

评估受威胁物种的数量与分布是保护生物学的核心难题之一，受关注物种往往生性罕见且难以捉摸，这进一步加剧了评估难度。对于部分食肉动物而言，其大范围稀疏分布的特性更让挑战雪上加霜，猎豹（Acinonyx jubatus）便是典型代表。国际自然保护联盟（IUCN）红色名录评估流程具备意见征集、民主公开、应用广泛的特点，且近期已完成该物种的评估工作。本文在此流程基础上提出补充方法，并提供可生成更精细数据的量化分析路径，同时可作为未来评估的参照基准。猎豹虽带来诸多评估挑战，却也具备独特研究优势：其一，其外形上镜，可通过众包渠道收集数千条观测数据；其二，猎豹因捕食家畜而遭到人类迫害，据此可通过迫害记录估算当地种群密度。在已知人类与家畜密度的区域中，迫害记录可用于推断无观测数据区域内猎豹的潜在分布情况。研究整合了大量遥测（telemetry）数据，以及来自39个来源的近20000条额外观测记录，结果显示：2010至2016年间，自由活动的猎豹广泛分布于纳米比亚、博茨瓦纳、南非与津巴布韦境内约789700平方千米的区域（占比分别为56%、22%、12%与10%），估算成年种群数量为3577只。此外，本研究在研究区域内识别出742800平方千米的潜在猎豹栖息地，这些区域人类与家畜密度较低，预计可容纳约3250只猎豹。与此前多数估算不同，本研究公开了全部原始数据，并明确给出了猎豹确有分布或大概率无分布的具体区域信息。尽管本次研究使用的多数数据来自游客密集的保护区，但我们仍强调公开数据源收集数据的重要价值。南部非洲存在一处连续的跨界猎豹种群，是全球规模最大的猎豹种群。研究发现，该种群约55%的自由活动个体集中分布于两个生态区，其受威胁程度或高于此前认知。该区域与迫害风险较高的商业农田重叠，成年猎豹的年移除率约为每100平方千米0.3只。本研究针对确认有猎豹分布区域的种群估算结果，较IUCN针对同一区域的当前评估低11%，这为近期将该物种从易危（Vulnerable）升级为濒危（Endangered）的呼吁提供了额外支撑。