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.

觅食介导的生态位分化（niche partitioning）是通过分离资源利用方式，促进生态位相似且同域分布的动物物种实现共存的潜在机制。然而，该机制在飞行食虫动物中的研究仍有待深入，尤以蝙蝠类群为甚——诸多生态位相似或隐存种（cryptic species）在此类群中共存。对同域分布的隐存姊妹种的觅食生态位开展详细分析，是厘清促进物种共存的特定生态位因子作用的极佳研究框架。本研究借助DNA元条形码技术（DNA metabarcoding），对同域分布的姊妹种宽耳菊头蝠（Rhinolophus euryale）与梅氏菊头蝠（R. mehelyi）的猎物种类进行了鉴定；此前针对该种群的无线电追踪（radio tracking）研究已明确二者在同域与异域分布区的栖息地利用模式。尽管二者在猎物组成上存在细微差异，但由于均大量取食同一类常见广布蛾类，其饮食重叠度极高（Ojk=0.83）。我们检测到的少量食性差异，可能与不同觅食生境中的猎物可获得性差异相关；而此前针对该种群的无线电追踪研究表明，当两种蝙蝠同域共存时，会差异化利用并选择这些生境。这种同域分布下的轻微食性分化，可能源于二者取食相同类型的猎物，或有助于降低潜在的种间竞争（如猎物资源、声学空间的竞争）。本研究结果强调，需评估空间生态位维度在介导相似食虫蝙蝠物种共存中的作用——这一生态位因子极有可能参与了蝙蝠物种的共存过程。