Citizen science reveals a geographic mosaic of trumpetfish shadowing behaviour in the Caribbean Sea

Citizen science is often used to assess the distribution and abundance of species, but it can be extended to identify the occurrence of different animal behaviours, generating hypotheses for the fields of behavioural ecology, conservation, and evolutionary biology. Here we use a targeted citizen science approach to map the prevalence and spatial spread of a fish’s unusual hunting strategy across the Caribbean Sea. Using a standardised questionnaire targeting regular scuba divers, we quantified the occurrence of a behaviour termed ‘shadowing’, where West Atlantic trumpetfish (Aulostomatus maculeatus) swim behind or next to another ‘host’ species when hunting prey. While the vast majority of participants observed trumpetfish on nearly every dive, using spatial analyses, we found the frequency of shadowing behaviour was geographically clustered within the Caribbean, particularly to within ~100 km ranges. Our survey also highlighted that shadowing behaviour was more likely to occur in particular habitat types, and with particular host species, suggesting potential mechanisms for such clustering. Our results not only identify a mosaic of different hunting behaviours across thousands of square kilometres, but more generally, demonstrates the power of using citizen science to investigate behaviours over spatial scales that would otherwise be unfeasible.

公民科学（citizen science）通常被用于评估物种的分布与种群丰度，其应用范畴还可进一步拓展至识别不同动物行为的发生情况，进而为行为生态学、保护生物学及进化生物学领域生成研究假说。本研究采用靶向式公民科学方法，绘制了加勒比海海域内某鱼类的非常规捕猎策略的流行率与空间扩散特征。我们针对资深水肺潜水员设计了标准化问卷，量化了一种被称为‘尾随捕猎’（shadowing）的行为的发生情况：西大西洋管口鱼（*Aulostomatus maculeatus*）在捕食猎物时，会尾随或紧邻另一种“宿主”物种。尽管绝大多数参与者表示几乎每次潜水都能观测到管口鱼，但通过空间分析我们发现，尾随捕猎行为的发生频率在加勒比海海域呈现地理聚集格局，且主要集中在约100公里的范围内。本次调查还显示，尾随捕猎行为更易在特定生境类型中发生，且与特定宿主物种相关联，这为该聚集现象的潜在作用机制提供了线索。本研究结果不仅揭示了数千平方公里海域内不同捕猎行为的镶嵌分布格局，更从更广泛的视角证明了利用公民科学方法，可在原本难以实现的空间尺度上开展行为学研究。