Friday, January 11, 2013

Large Blue Flycatcher?

A couple of days ago I emailed my bird records for December to Phil Round. He was interested by the record of "Chinese Blue Flycatcher" that I had seen with Richard Bonser and David Lindo at Suan Rot Fai just before Christmas, and asked to see the images I had taken.  On submitting the pictures to Phil he pinged back a short message indicating that he felt the bird might in fact be a Large Blue Flycatcher Cyornis magnirostris - a recent split from Hill Blue Flycatcher and poorly known on its wintering grounds in Malaysia and southern Thailand (known as a breeding bird from Myanmar and the eastern Himalayas), infact it is so poorly known that if this record was confirmed it would be the first confirmed field record for Thailand (see the short paper here regarding another possible seen in southern Thailand, in March 2011).  Cyornis ID and taxonomy is complex, and it seems possible to have sedentary and migrant races of the same species in the same locations at the same time!  Given that the ID is very difficult even in adult males, let alone in females and immature birds, i don't feel so devasted that I might have missed out on finding "a biggie" though I'm a bit annoyed with myself for not emailing the photos to Phil on the day that I took them, as it did cross my mind to get a second opinion (humfph!).  Phil's main reasons for suspecting the ID as  C. magnirostris comes from the rather extensive orange wash on the throat, and the fact that the bird's lower mandible is extensively pale. However without trapping the bird for taking biometrics it seems like this will not be resolved.  Today I went to the spot where I had seen the bird but unfortunately there was no sign of it - perhaps not surprising, though last winter the same area held a male Chinese Blue Flycatcher for several weeks in mid-winter. So, it seems that is is probably one that got away.  The only consolation whilst looking for it this afternoon was that I found a Claudia's Leaf Warbler, which in itself was a patch tick.
24th Dec, 2012

Large Blue Flycatcher is noted to show a throat that is paler that the breast.  The bill of Large Blue Fly is supposed to have a significantly pale lower mandible, and a pronounced hook to it's tip.  These features seem to be apparent in the bird seen at Suan Rot Fai.

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