Data from: The complex phylogeography of the Indo-Malayan Alophoixus bulbuls with the description of a putative new ring species complex

The Indo-Malayan bioregion has provided some of the most spectacular
discoveries of new vertebrate species (e.g. saola, khanyou, bare-faced
bulbul) over the last 25 years. Yet, very little is known about the
processes that led to the current biodiversity in this region. We
reconstructed the phylogeographic history of a group of closely related
passerines, the Alophoixus bulbuls. These birds are continuously
distributed in Indo-Malaya around the Thailand lowlands such that their
distribution resembles a ring. Our analyses revealed a single colonization
event of the mainland from Sundaland with sequential divergence of taxa
from southwest to northeast characterized by significant gene flow between
parapatric taxa, and reduced or ancient gene flow involving the two taxa
at the extremities of the ring. We detected evidence of population
expansion in two subspecies, including one that was involved in the
closing of the ring. Hence, our analyses indicate that the diversification
pattern of Alophoixus bulbuls fits a ring species model driven by
geographic isolation. To our knowledge, the Alophoixus bulbuls represent
the first case of a putative broken ring species complex in Indo-Malaya.
We also discuss the implications of our results on our understanding of
the biogeography in Indo-Malaya.