The radiation of Austral teals (Aves: Anseriformes) and the evolution of flightlessness

A new whole-mitogenome-based phylogeny reveals that Austral teals, including the grey-teal and brown-teal complexes, diverged from mallards in the late Miocene. The study shows that the brown-teal lineage, which includes both volant and flightless species, radiated within the past 0.9–1.8 million years, with morphological changes toward flightlessness already present in the mainland brown teal. This suggests an accelerating trend of flightlessness in insular lineages, including the sub-Antarctic Auckland Island teal and the extinct Chatham Island teal, both derived from New Zealand ancestors. The findings provide critical insights into the evolutionary pathways leading to flightlessness, offering valuable data for functional genomic studies.

Rosinger, H. S., Kardailsky, O., Kennedy, M., Spencer, H. G., Steiner, F. M., Schlick-Steiner, B. C., Rawlence, N. J., & Knapp, M. (2024). The radiation of Austral teals (Aves: Anseriformes) and the evolution of flightlessness. Zoological Journal of the Linnean Society, 201(4). https://doi.org/10.1093/zoolinnean/zlae036