Genomic data help uncover extinction-in-progress of unsustainably traded Hill Myna radiation

The Asian Songbird Crisis, which is currently unfolding in Southeast Asia, has seen multiple bird taxa go extinct in the wild and even more slip into regional or local extinction over the span of only a few years. The Hill Mynas Gracula spp. are amongst its main victims, encompassing the Critically Endangered Nias Hill Myna Gracula robusta and other endangered populations across the West Sumatran Archipelago. Hill Mynas are known to be present throughout this island chain but taxonomic relationships of West Sumatran Gracula populations remain poorly understood. We hypothesised that the unique geologic history of this island chain may have given rise to multiple distinct insular forms. Here we use genome-wide DNA data in concert with morphological analyses to investigate the evolutionary distinctness of these taxa. Our results indicate at least one distinct yet largely unrecognised lineage, the ‘Simeulue Hill Myna’ (taxon miotera), and a range extension of the Nias Hill Myna. Despite their lack of recognition, Simeulue Hill Mynas are genomically and morphologically as unique as their Nias counterpart, in accordance with the lack of glacial land bridges between the island of Simeulue and mainland Sumatra. Simeulue Hill Mynas went extinct in the wild some time within the last 2–3 years, and the rescue of the last captive individuals should now be the highest priority.