White-breasted Robin Eopsaltria georgiana |
“Peculiar” was Leach’s more prosaic assessment [2]. Taxonomy of the White-breasted Robin has been surprisingly controversial, given that to superficial appearances it seems a typical (if colourless) Eopsaltria robin. It shares many mannerisms with the Eastern and Western Yellow Robins, such as the habit of clinging sideways to low trunks and branches, motionless except for occasional flicking of the tail and wings. Like them it is initially shy but hopelessly inquisitive, and cannot resist checking you out if you sit still for a moment. Indeed it is so similar to the Yellow Robins that this complex has long been considered a classic example of speciation by double invasion, with successive waves into the south-west forests evolving to lose all (White-breasted Robin) or half (Western Yellow Robin) of an originally fully yellow breast (Eastern Yellow Robin).
However it has sufficient differences from the Yellow Robins, particularly its eggs, to persistently trouble taxonomists. Campbell first removed it from Eopsaltria to Amaurodryas (now Melanodryas) based on a perceived “oological” association with the Dusky Robin of Tasmania; Mathews lumped it instead with Mangrove Robin in the genus Quoyornis, where it remained isolated for some time after Mangrove Robin was split off to yet another monospecific genus Peneonanthe [2]. However a 2009 molecular phylogenetic study [3] reported the unexpected finding that the White-breasted Robin may instead be most closely related to the ‘other’ yellow robins - the two Tregellasia robins (the White-faced and Pale Yellow Robin of north-eastern rainforests).
UPDATE: Christidis et al 2011 [6] confimed this unexpected paraphyletic status of Eopsaltria and recommended that White-breasted Robin return to the genus Quoyornis.
UPDATE: Christidis et al 2011 [6] confimed this unexpected paraphyletic status of Eopsaltria and recommended that White-breasted Robin return to the genus Quoyornis.