Palawan Fairy-bluebird Irena tweeddalii is split from Asian Fairy-bluebird Irena puella (Clements 2007:569)

Summary: The forests of the Palawan island group of the southwestern Philippines are the sole home of the Palawan Fairy-bluebird.

Details: All five taxa long recognized as subspecies of Irena puella (e.g., Mayr and Greenway 1960c) were originally described as separate species, although all are generally similar in their striking plumage pattern, which is unique to this complex. On the basis of mtDNA and nuclear DNA, Moltesen et al. (2012) and Lim et al. (2020) found that the Palawan form tweeddalii was sister to all other taxa of Irena puella. In addition to this evidence, del Hoyo and Collar (2016) enumerated multiple morphological differences that led them to consider I. tweeddalii as a distinct species, as did Eaton et al. (2016), Allen (2020), and Gill et al. (2021, IOC v.11.2). The few available recordings of tweeddalii suggest vocal differences. WGAC and Clements et al. (2023) consider that the evidence favors the treatment of tweeddalii as a full species.