Kalahari vulture declines, through the eyes of meerkats§

Vulture populations are experiencing rapid declines across the globe. While the declines have been most precipitous in Asia, recent reports suggest African populations are likewise imminently threatened. As the factors underlying these general population trends are multifaceted and will vary in their relative intensity spatially, it is imperative that monitoring data across different vulture populations is assimilated if targeted conservation action is to prove most effective. In this study, we highlight a medium-term decline in the African White-backed Vulture Gyps africanus population inhabiting the southern Kalahari, South Africa, using a long-term behavioural data set collected from a habituated population of meerkats Suricata suricatta. Meerkats emit an alarm call on sighting airborne vultures, which elicits a group-level response, such that the rates at which this behaviour is recorded in meerkats provides a high-resolution proxy for local vulture abundance. Although unconventional, this sampling method uncovered a steady decline over 17 years in White-backed Vulture numbers that mirrors the temporal decline recently documented in other southern African populations.

全球范围内的秃鹫种群正经历快速衰退。尽管亚洲的种群衰退最为剧烈，但近期报告显示非洲秃鹫种群同样面临迫在眉睫的生存威胁。鉴于驱动这些整体种群趋势的因素复杂多样，且其相对影响强度存在空间异质性，若要使针对性保护行动达到最优成效，就必须整合来自不同秃鹫种群的监测数据。本研究依托南非喀拉哈里南部地区一群习惯化狐獴（Suricata suricatta）的长期行为数据集，揭示了当地栖息的非洲白背秃鹫（Gyps africanus）种群存在中期衰退现象。狐獴在发现飞行中的秃鹫时会发出警戒叫声，这一行为会触发群体响应，因此狐獴记录该行为的频率可作为当地秃鹫种群丰度的高分辨率替代指标。尽管该采样方法并非传统手段，但它揭示了过去17年间非洲白背秃鹫种群数量的持续下降趋势，这一趋势与近期南非其他南部种群记录到的时间维度衰退情况相符。