title: Genome-wide data help identify an avian species-level lineage that is morphologically and vocally cryptic.
abstract: Species identification has traditionally relied on morphology. However, morphological conservatism can lead to a high incidence of cryptic species, as characters other than morphological ones can be biologically important. In birds, the combined application of bioacoustic and molecular criteria has led to an avalanche of cryptic species discoveries over the last two decades in which findings of deep vocal differentiation have usually been corroborated by molecular data or vice versa. In this study, we use genome-wide DNA data to uncover an unusual case of cryptic speciation in two species within the South-east Asian Streak-eared Bulbul Pycnonotus blanfordi complex, in which both morphology and vocalizations have remained extremely similar. Despite a considerable pre-Pleistocene divergence of these two bulbul species, bioacoustic analysis failed to uncover differences in their main vocalization, but examination of live birds revealed important differences in eye color that had been overlooked in museum material. Our study demonstrates that genome-wide DNA data can be helpful in the detection of cryptic speciation, especially in species that have evolved limited morphological and behavioral differences.
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Kritika M
authors.initials: KM
authors.lastname: Garg
authors.affiliation: Wildlife Conservation Society, Yangon, Myanmar.
authors.forename: Robert
authors.initials: R
authors.lastname: Tizard
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Nathaniel S R
authors.initials: NS
authors.lastname: Ng
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Emilie
authors.initials: E
authors.lastname: Cros
authors.affiliation: Institute of Experimental Ecology, University of Ulm, Germany; Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
authors.forename: Ariya
authors.initials: A
authors.lastname: Dejtaradol
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Balaji
authors.initials: B
authors.lastname: Chattopadhyay
authors.affiliation: Nature and Wildlife Conservation Division, Naypyitaw, Myanmar.
authors.forename: Nila
authors.initials: N
authors.lastname: Pwint
authors.affiliation: Senckenberg Natural History Collections, Königsbrücker Landstraße 159, D-01109 Dresden, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Päckert
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore. Electronic address: dbsrfe@nus.edu.sg.
authors.forename: Frank E
authors.initials: FE
authors.lastname: Rheindt
mesh_terms: D000162:Acoustics; D000818:Animals; D004247:DNA / Q000235:genetics; D016678:Genome; D005843:Geography; D046109:Passeriformes / Q000033:anatomy & histology* / Q000235:genetics*; D010802:Phylogeny; D010858:Pigmentation; D025341:Principal Component Analysis; D017422:Sequence Analysis, DNA; D014828:Vocalization, Animal
chemical_list: D004247:DNA
keywords: Myanmar; Speciation; Thailand; ddRAD-Seq