Spatial Patterns of Movement of Dung Beetle Species in a Tropical Forest Suggest a New Trap Spacing for Dung Beetle Biodiversity Studies

A primary goal of community ecologists is to understand the processes underlying the spatiotemporal patterns of species distribution. Understanding the dispersal process is of great interest in ecology because it is related to several mechanisms driving community structure. We investigated the mobility of dung beetles using mark-release-recapture technique, and tested the usefulness of the current recommendation for interaction distance between baited pitfall traps in the Brazilian Atlantic Forest. We found differences in mean movement rate between Scarabaeinae species, and between species with different sets of ecological traits. Large-diurnal-tunneler species showed greater mobility than did both large-nocturnal tunneler and roller species. Our results suggest that, based on the analyses of the whole community or the species with the highest number of recaptured individuals, the minimum distance of 50 m between pairs of baited pitfall traps proposed roughly 10 years ago is inadequate. Dung beetle species with different sets of ecological traits may differ in their dispersal ability, so we suggest a new minimum distance of 100 m between pairs of traps to minimize interference between baited pitfall traps for sampling copronecrophagous Scarabaeinae dung beetles.群落生态学研究者的核心目标之一，是阐明物种分布时空格局的底层驱动机制。在生态学领域，扩散过程的解析始终是研究热点，因其与塑造群落结构的多项核心机制紧密相关。本研究采用标记-释放-重捕（mark-release-recapture）技术，对蜣螂的移动能力开展调查，并针对巴西大西洋森林（Brazilian Atlantic Forest）中现行推荐的诱饵式地面陷阱（baited pitfall trap）交互间距的实用性进行了检验。研究发现，蜣螂亚科（Scarabaeinae）不同物种间，以及具有不同生态特征组合的物种间，平均移动速率存在显著差异。昼行性大型隧洞型蜣螂的移动能力，显著高于夜行性大型隧洞型与滚球型蜣螂。研究结果表明，若基于整个群落或重捕个体数最多的物种开展分析，约10年前提出的“诱饵式地面陷阱对间距不低于50米”的标准并不充分。鉴于具有不同生态特征组合的蜣螂物种，其扩散能力存在差异，本研究建议将诱饵式地面陷阱对的最小间距调整为100米，以最大限度降低诱集取样食粪性蜣螂亚科（Scarabaeinae）时陷阱间的相互干扰。