Integrative taxonomy of eared nightjars (Aves: Lyncornis) underscores the complementarity of morphology, vocalizations and DNA evidence

Abstract

Abstract The eared nightjars (Lyncornis, formerly Eurostopodus) comprise six taxa distributed from southern India and Southeast Asia to Sulawesi. Species limits in this group have not been evaluated since 1940. In this study, we use three datasets (morphology, acoustics and mitochondrial DNA) to assess the taxonomic status of taxa in this genus. Multivariate analyses of vocalizations and phylogenetic analysis of mitochondrial DNA both revealed the presence of four major groups. Morphological analyses also revealed four major groups, but these agreed only in part with those identified by vocalizations and DNA. Lyncornis macrotis cerviniceps from mainland Southeast Asia and the isolated Lyncornis macrotis jacobsoni on Simeulue Island, off north-west Sumatra, differed by six diagnostic plumage characters, but could not be distinguished by their vocalizations or mitochondrial DNA. Conversely, Lyncornis macrotis macrotis from the Philippines and Lyncornis macrotis macropterus from Sulawesi differed diagnosably in song and by 5% sequence divergence but could not be diagnosed by plumage. We adopt an integrative approach and propose to recognize five monotypic species: Lyncornis temminckii, Lyncornis cerviniceps (synonym: Lyncornis bourdilloni), Lyncornis jacobsoni, Lyncornis macrotis and Lyncornis macropterus. Our study illustrates that taxonomic revisions based on single lines of evidence can underestimate diversity and underscores the importance of using multiple datasets in species-level taxonomy.