• We used genome-wide data to explore the Pycnonotus blanfordi complex.
• No vocal differentiation within the P. blanfordi complex.
• P. blanfordi and P. conradi differ in eye color.
• We uncovered cryptic diversity hitherto unrecognized.
|The Streak-eared bulbul [Pycnonotus b. conradi] on the left, is visually similar to the Ayeyawady bulbul [Pycnonotus b. blanfordi] on the right despite having strikingly different genetic data. |
Photos: Robert J Tizard (left), Thet Zaw Naing (right).
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.
Keywords: ddRAD-Seq; Myanmar; Thailand; Speciation
Kritika M. Garg, Robert Tizard, Nathaniel S.R. Ng, Emilie Cros, Ariya Dejtaradol, Balaji Chattopadhyay, Nila Pwint, Martin Päckert and Frank E. Rheindt. 2016. Genome-Wide Data Help Identify An Avian Species-Level Lineage That Is Morphologically and Vocally Cryptic. Molecular Phylogenetics and Evolution. DOI: 10.1016/j.ympev.2016.05.028
DNA testing challenges traditional species classification https://myanmarbiodiversity.org/2016/dna-testing-challenges-traditional-species-classification/