A metabarcoding assessment of the diet of insectivorous bats on the subtropical Madeira Island

Understanding the trophic structure of species assemblages is crucial in order to comprehend how syntropic species coexist in space and time. Bats are the second most taxonomically diverse group of mammals and display a wide range of dietary strategies. Due to their ability to disperse over water, ca. 60% of all extant bat species occur on islands and for the most part their interspecific ecological interactions are poorly known. Using DNA metabarcoding, this study offers the first insights into the diet of Macaronesian bats by providing a holistic overview of prey consumed by all 3 bat species found on Madeira Island (Pipistrellus maderensis, Nyctalus leisleri verrucosus and Plecotus austriacus) and investigating both interspecific (between P. maderensis and N. l. verrucosus) and intraspecific (between female and male N. l. verrucosus) dietary differences. We identified a total of 110 species of arthropod prey in the diet of the 3 bat species, including multiple agriculture and forestry pest species, a human disease-relevant species, and numerous taxa not previously recorded on the island. Lepidoptera was the primary prey order for all 3 bat species. The diet composition of P. maderensis and N. l. verrucosus differed significantly, with P. maderensis consuming more Diptera and multiple prey taxa not found in the diet of N. l. verucosus. Moreover, male N. l. verrucosus exhibited a broader niche breadth than females. This study is amongst the first to use DNA metabarcoding to evaluate the diet of insular bats and thus greatly advances knowledge regarding the trophic ecology and pest suppression services of these poorly
known mammals.

阐明物种集合的营养结构，对于理解协同共存物种如何在时空维度上实现共生至关重要。蝙蝠是哺乳动物中分类多样性第二高的类群，且具备极为丰富的取食策略。由于蝙蝠具备跨水域扩散的能力，现存蝙蝠物种中约60%栖息于岛屿生态系统，但其种间生态互作的相关研究仍极为匮乏。本研究借助DNA元条形码（DNA metabarcoding）技术，对马卡罗尼西亚蝙蝠的食性展开首次系统性探究：全面分析了马德拉岛上已发现的3种蝙蝠（马德拉伏翼（Pipistrellus maderensis）、利氏蝙蝠疣亚种（Nyctalus leisleri verrucosus）以及灰长耳蝠（Plecotus austriacus））的捕食猎物组成，并同时考察了种间（马德拉伏翼与利氏蝙蝠疣亚种）与种内（利氏蝙蝠疣亚种雌雄个体间）的食性差异。本研究共在3种蝙蝠的食性中鉴定出110种节肢动物猎物，其中包含多种农林业害虫、1种与人类疾病相关的物种，以及此前未在该岛有记录的诸多类群。鳞翅目是3种蝙蝠共有的核心捕食类群。马德拉伏翼与利氏蝙蝠疣亚种的食性组成存在显著差异：马德拉伏翼更多取食双翅目昆虫，且包含利氏蝙蝠疣亚种食谱中未出现的多种猎物类群。此外，利氏蝙蝠疣亚种的雄性个体较雌性具有更宽泛的生态位宽度。本研究是首批利用DNA元条形码技术评估岛屿蝙蝠食性的研究之一，极大拓展了学界对这类鲜为人知的哺乳动物的营养生态学与害虫抑制生态服务功能的认知。