Data from: Assessing niche partitioning of co-occurring sibling bat species by DNA metabarcoding

Niche partitioning through foraging is a mechanism likely involved in facilitating the coexistence of ecologically similar and co-occurring animal species by separating their use of resources. Yet, this mechanism is not well understood in flying insectivorous animals. This is particularly true of bats, where many ecologically similar or cryptic species coexist. The detailed analysis of the foraging niche in sympatric, cryptic sibling species provides an excellent framework to disentangle the role of specific niche factors likely involved in facilitating coexistence. We used DNA metabarcoding to determine the prey species consumed by a population of sympatric sibling Rhinolophus euryale and R. mehelyi whose use of habitat in both sympatric and allopatric ranges has been well established through radio tracking. Although some subtle dietary differences exist in prey species composition, the diet of both bats greatly overlapped (Ojk = 0.83) due to the consumption of the same common and widespread moths. Those dietary differences we did detect might be related to divergences in prey availabilities among foraging habitats, which prior radio tracking on the same population showed are differentially used and selected when both species co-occur. This minor dietary segregation in sympatry may be the result of foraging on the same prey-types and could contribute to reduce potential competitive interactions (e.g. for prey, acoustic space). Our results highlight the need to evaluate the spatial niche dimension in mediating the co-occurrence of similar insectivorous bat species, a niche factor likely involved in processes of bat species coexistence.

通过觅食实现的生态位分化（niche partitioning）是一种潜在机制，该机制通过分离资源利用方式，助力生态习性相似且同域分布的动物物种实现共存。然而，该机制在飞行食虫动物类群中的研究仍较为匮乏，对于蝙蝠类群而言尤为如此——蝙蝠类群中存在大量生态习性相似或隐存的同域共存物种。对同域分布的隐存姊妹种开展觅食生态位的详细分析，为厘清助力物种共存的特定生态位因子的作用提供了极佳的研究框架。本研究利用DNA元条形码（DNA metabarcoding）技术，对同域分布的姊妹种——中菊头蝠（Rhinolophus euryale）与梅氏菊头蝠（Rhinolophus mehelyi）种群的捕食猎物物种进行了鉴定；此前已有研究通过无线电追踪明确了这两个物种在同域与异域分布区的栖息地利用模式。尽管二者在猎物物种组成上存在细微的饮食差异，但由于均取食同类常见且广布的蛾类，两种蝙蝠的饮食生态位重叠度极高（Ojk=0.83）。本研究观测到的这些饮食差异，可能与不同觅食生境中的猎物可获得性差异有关；而针对该种群的既往无线电追踪研究表明，当两种蝙蝠同域共存时，它们会差异化利用并选择不同的觅食生境。同域分布种群中出现的这种轻微的饮食分化，可能源于二者取食同类猎物类型，这或许有助于降低潜在的种间竞争互动（例如针对猎物、声学空间的竞争）。本研究结果表明，亟需评估空间生态位维度在介导相似食虫蝙蝠物种同域共存中的作用——这一生态位因子极有可能参与了蝙蝠物种的共存过程。