Rapid loss of flight in the Aldabra white-throated rail

Research on the Aldabra white-throated rail (Dryolimnas [cuvieri] aldabranus) reveals one of the most rapid cases of avian flight loss, occurring within 80,000 to 130,000 years. This unique subspecies is the sole surviving flightless bird in the western Indian Ocean and the only flightless member of its otherwise volant species, Dryolimnas cuvieri. Genetic and morphological analyses indicate that this rapid evolution of flightlessness is accompanied by significant genetic divergence from its flying relatives, surpassing typical levels seen between close relatives with full species status. The study suggests that D. [c.] aldabranus should be recognized as an evolutionary significant unit for conservation purposes, highlighting the importance of considering trait variability—such as flightlessness—in assessing extinction risk.

van de Crommenacker, J., Bunbury, N., Jackson, H. A., Nupen, L. J., Wanless, R., Fleischer-Dogley, F., Groombridge, J. J., & Warren, B. H. (2019). Rapid loss of flight in the Aldabra white-throated rail. Plos One, 14(12), e0226064. https://doi.org/10.1371/journal.pone.0226064