Great find Author: brendank Time: 22/10/2011 21:52
I find Green-backed Flycatcher interesting counterexample to Geoff's theory. It seems most of our spring migrants come from the Philippines while most of our autumn migrants are headed to South East Asia. This species winters in Vietnam and Malaysia as far as I have read. Green-backed and Yellow-rumped Flycatchers are scarce winter visitors to Singapore while Narcissus is only a vagrant. So I would expect this species more in the autumn. Seems, however, that the opposite is true. Author: kkoel Time: 22/10/2011 23:19
Thanks for everyone's comments!
Brendan: could this apparent "trend" be the result of a) small sample size from HK and b) uncertainty in identifying female type "Narcissus Flycatchers"? The population of elisae and owstoni may not be very big, so we may not be able to observe the effect of elisae being commoner in autumn than spring. Perhaps just so happened that one or two more tame elisae have been present in spring before! Author: wgeoff Time: 23/10/2011 04:30
As Koel says, there is uncertainty in identifying 'female-type' (i.e. including some first-summer males) Green-backed Flycatchers as either Green-backed (elisae) or Narcissus (owstoni).
None of the records of female-type Green-backed since 2005 have been accepted to species. There have been five, including this one, three in spring and two in autumn. So it's possible the spring ones are owstoni (which winter in Philippines) and the autumn ones are Green-backed (which winter in SE Asia). All the accepted male owstoni (four since the first in 2002) have been in spring. There haven't been any male Green-backed since the late 90's (although the two accepted records from 1996 and 1997 were spring, so that's a bit confusing).
There are other factors. The Philippines is so large and underwatched, we don't know for sure which species winter there and the populations of elisae and owstoni is small.
I prefer to use nominate Narcissus and Yellow-rumped as examples. These are annual spring and autumn migrants respectively in Hong Kong and are known to winter fairly exclusively in Philippines and SE Asia respectively. But even then, we get the occasional ones in the 'wrong' season.
[ Last edited by wgeoff at 23/10/2011 09:00 ] Author: kmike Time: 23/10/2011 11:00
This bird is so bright I wondered if it may actually be a first winter male?
According to the Nial Moores paper on the Birds Korea websitea bird that is so smoothly green above and so brightly and uniformly yellow below should be readily identifiable as elisae - and the illustrations and text in Brazil appear to support this.
Would any of the records committee care to comment?
Cheers
Mike Author: wgeoff Time: 23/10/2011 16:40
You may be right Mike, but I guess the Records Committee would prefer to make a collective decision and then give the reasons behind it. It's already in the file to be processed. Author: kkoel Time: 24/10/2011 20:20
One more record shot from the same day to show the back of the bird - there is no hint of yellow rump patch, the lores are not pure yellow, and the wings are not blackish, which support sexing as female. However as Mike pointed out, the intensity of coloring suggests possibility of this being a juvenile male. It's now October, so is it possible that first-calendar males moult into male-type plumage only at a later stage?
[ Last edited by kkoel at 24/10/2011 20:22 ] Author: brendank Time: 24/10/2011 21:49
I am also wondering if it is first-calender male. If it is a female, I am bothered by the color of the undertail coverts which is mostly yellow and the color of the tail which is quite green. The website would suggest that adult females should have rather white undertail coverts.
[ Last edited by brendank at 25/10/2011 14:59 ] Author: ajohn Time: 25/10/2011 09:16
The pattern of the coverts/tertials and the apparent contrast between moulted and unmoulted greater coverts would suggest that this is a first year bird. I would be surprised if females were this bright in the first year, so I agree that this is a first year male.
The remaining question is whether that confirms this to be Green-backed, or whether owstoni is still a possibility. Author: kkoel Time: 26/10/2011 18:02
Re John's comment, from the paper by Nial Moores it seems that the contrast between rusty-tipped outer greater coverts and the white-tipped inner greater coverts (which I noticed during observation but didn't think would actually be relevant) and the relatively plain greater and median coverts suggest elisae over owstoni. In addition, the yellow underparts and uniformly coloured cream eye-ring also supports this being an elisae.
Re Brendan, actually the under-tail coverts of this bird are white and contrasts with the yellow belly, but due to the under-storey lighting the photos looked yellower than in the field!
[ Last edited by kkoel at 26/10/2011 18:04 ] Author: brendank Time: 26/10/2011 22:15
I felt the undertail coverts were reasonably yellow--even in my backlight photo from below you can see quite a bit of yellow. But this doesn't surprise me for immature male elisae. Adult elisae do have quite yellow undertail coverts from the photos I have seen on the web. Author: bittern Time: 29/10/2011 20:20
So where is the bird now?
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