Integrated approaches to identifying cryptic bat species in areas of high endemism: The case of Rhinolophus andamanensis in the Andaman Islands

The diversity of bats worldwide includes large numbers of cryptic species, partly because divergence in acoustic traits such as echolocation calls are under stronger selection than differences in visual appearance in these nocturnal mammals. Island faunas often contain disproportionate numbers of endemic species, and hence we might expect cryptic, endemic species to be discovered relatively frequently in bats inhabiting islands. Species are best defined when multiple lines of evidence supports their diagnosis. Here we use morphometric, acoustic, and molecular phylogenetic data to show that a horseshoe bat in the Andaman Islands is distinct in all three aspects, supporting its status as a distinct species. We recommend investigation into possible new and endemic bat species on islands by using integrated approaches that provide independent lines of evidence for taxonomic distinctiveness. We provide a formal redescription of the taxon newly raised to species level, Rhinolophus andamanensis Dobson, 1872.

全球蝙蝠类群的多样性中包含大量隐存种（cryptic species），这一现象的部分原因在于：相较于这类夜行性哺乳动物的视觉外观差异，回声定位叫声（echolocation calls）等声学性状的分化受到更强的选择压。岛屿动物区系（island faunas）通常存在特有种（endemic species）比例偏高的情况，因此我们可以预期，栖息于岛屿的蝙蝠类群中会相对频繁地发现隐存特有种。当有多条独立证据支持物种鉴定时，物种的界定最为严谨可靠。本研究通过整合形态测量学、声学与分子系统发育数据，证实安达曼群岛的一种菊头蝠（horseshoe bat）在这三类特征维度上均表现出显著分化，支持其作为独立物种的分类地位。我们建议采用能够提供分类学独特性独立证据的整合研究方法，对岛屿上可能存在的新型特有蝙蝠类群开展调查。本研究对新提升至物种级的分类单元——安达曼菊头蝠（Rhinolophus andamanensis Dobson, 1872）进行了正式的重新描述。