Monitoring compliance of CITES lion bone exports from South Africa

From 2008 to 2018, South Africa permitted the export of captive-bred African lion (Panthera leo) skeletons to Southeast Asia. Exports rose from approximately 50 individuals in 2008 to a maximum of 1,771 skeletons in 2016, leading to concerns over possible laundering of non-lion, multiple-source and wild material. Monitoring tools for the legal trade in lion bones are critical to CITES compliance, ensuring that i) other species are not laundered as lion, ii) all bones in a consignment comprise of a known number of unique individuals to avoid ‘pooling’ or ‘tag-swopping’, and iii) each individual can be traced to their captive origin. In addition to exploring conventional skull morphology- and weight-based monitoring techniques, a CITES-compliant genetic monitoring protocol to confirm the species, individual identity, and thereby the origin of legally traded lion bones was developed and validated. We traced 800 and 799 lion bone samples obtained under ‘chain-of-custody’ sampling from the 2017 and 2018 lion bone quotas, respectively, while an additional 25 and 102 random ‘spot-checked’ samples were collected at the airport prior to export. A real-time polymerase chain reaction was used for species assignment, while pairwise-comparative sample matching of individual DNA profiles and origin tracing analyses were conducted using 18–23 microsatellite markers. There are significant differences in lion skeleton weights: farm weights (listed on CITES export permits) are heavier than export weights, and skeletons in more recent trade are heavier than in preceding years. Monitoring skeleton weight profiles can provide significant regulatory advantages when correctly applied, but it may be prone to misinterpretation and should be considered in the full context of the procedural system. Molecular identification of individuals and species successfully highlighted ten anomalies in comparative sample matching of individual pairs with the same tag number between source farms and airport spot-checks, excluding one overt attempt at laundering. We here provide both the lion weight and genetic profile data to support these analyses.

2008年至2018年间，南非允许将圈养繁殖的非洲狮（Panthera leo）骨骼出口至东南亚地区。其出口量从2008年的约50头个体升至2016年的峰值1771具骨骼，这引发了人们对非狮类、多来源及野生材料可能被非法洗白的担忧。针对狮骨合法贸易的监测工具，是确保符合《濒危野生动植物种国际贸易公约》（CITES）要求的关键，具体需满足三项标准：i）不得将其他物种冒充为狮骨；ii）同一批次货物中的所有骨骼均来自已知数量的独个个体，以避免“集中混放”（pooling）或“标签调换”（tag-swopping）；iii）每一头个体均可追溯至其圈养来源。
除了探索基于常规头骨形态与体重的监测技术外，本研究还开发并验证了一套符合CITES规范的遗传监测方案，可用于确认物种、个体身份，进而确定合法交易狮骨的来源。我们对分别取自2017年和2018年狮骨配额、遵循“监管链”采样流程获取的800份和799份狮骨样本进行了溯源分析，同时在出口前于机场随机采集了25份和102份“现场抽检”样本。本研究采用实时聚合酶链式反应（real-time polymerase chain reaction）进行物种鉴定，并利用18至23个微卫星标记（microsatellite markers）完成个体DNA图谱的两两比对匹配及来源溯源分析。
狮骨骼体重存在显著差异：CITES出口许可上标注的养殖场体重高于实际出口体重，且近年交易的骨骼体重高于此前年份。若正确应用骨骼体重分布监测方法，可带来显著的监管优势，但该手段可能存在解读偏差，因此应结合完整的监管流程背景进行综合考量。对个体及物种的分子鉴定，成功在源养殖场与机场抽检样本间、带有相同标签编号的配对样本比对中发现了10处异常，排除了1起明显的非法洗白尝试。本文同步提供狮骨骼体重及遗传图谱数据，以支撑上述各项分析工作。