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.

通过觅食行为实现的生态位分化（niche partitioning），是一类通过分离资源利用模式，助力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类群中尚未得到充分阐释，尤以蝙蝠类群为甚——许多生态位相似或隐存近缘种在此类群中共存。对同域分布的隐存近缘种觅食生态位开展细致分析，是厘清助力物种共存的特定生态位因子作用机制的绝佳研究框架。本研究借助DNA宏条形码技术（DNA metabarcoding），对同域分布的近缘种宽耳菊头蝠（Rhinolophus euryale）与梅氏菊头蝠（R. mehelyi）种群的猎物种类进行了鉴定；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差异，但由于均取食同类常见且广布的蛾类，两者的饮食重叠度极高（Ojk=0.83）。我们检测到的这些饮食差异，可能与不同觅食生境下的猎物可获得性差异相关；而针对该种群的既往无线电追踪研究显示，当两个物种同域分布时，它们会差异化利用并选择不同的觅食生境。这种同域分布下的轻微饮食生态位分化，可能源于二者取食同类猎物类型，或可助力降低潜在的种间竞争交互作用（如猎物资源、声学空间竞争）。本研究结果凸显了评估空间生态位维度在介导相似食虫蝙蝠物种同域共存过程中作用的必要性——该生态位因子极有可能参与了蝙蝠物种的共存调控过程。