Interesting bird! I agree that this is not an adult bird; in early September I think it is more likely to be in its first calendar year rather than second calendar year as the latter should have completed a wing/tail note by this date I think. However, I don't think it is a first winter male Hanian Blue Flycatcher. The latter has limited blue on the head and body feathers at this time (presumably these are moulted later in the winter). A second reason why not a Hainan Blue is the rather sharp transition between the blue throat and breast. This does not fit with a bird which is moulting into adult Hainan Blue plumage (where the blue extends onto the breast).
Agreed that it cannot be either Chinese Blue or klossi Blue-throated due to solidly blue throat: this leaves it as one of the three 'Blue-throated Blue' races. It doesn't look like bominate rubeculoides from India and I suspect that it is one of the South-east Asian taxa, either rogersi from Burma or, perhaps dialimaemus from Burma/Thailand.
Natural occurence from either NW Thailand or Burma seems unlikely so I suspect that this bird is not of truly wild origin; that is not to say that this individual was not hatched in the wild!
Mike Leven
