[ Last edited by Andiona at 29/12/2012 22:25 ] Author: lpaul Time: 11/12/2012 14:28
Such nice birds...and great photos! Author: kkoel Time: 11/12/2012 16:33
Congratulations Andiona, very nice shots of a beautiful bird!
However with such a contrasting head pattern: black lores, well delineated eyebrow and white patch below the eye, along with some grey colour over the cheeks, I think this bird may fit a first winter Eyebrowed Thrush better. As female-type Brown-headed Thrush do look very similar, I'm happy to stand corrected!
One more photo to show how brown-headed some immature male Eyebroweds can look. The white patch below the eye and dark lores seems to be absent in female-type Brown-headed Thrushes, whilst the white brow and black moustache could be common to both.
I also suspect this may be an Eyebrowed Thrush. There seems to be a lot of white in the area under and in front of the eye, the bill seems less heavy than some Brown-headed Thrush on OBC images, and the birds seems rather slim overall. However, I don't really see any mark that is completely definitive.
[ Last edited by brendank at 11/12/2012 21:43 ] Author: kkoel Time: 11/12/2012 18:56
I agree this may well be indeterminate - the extent and saturation of red underneath is good for Brown-headed but the head pattern I would say is a bit too strong for any Brown-headed I've seen online or in the field. Maybe birdwatchers more experienced with these two species could enlighten us? ^^ Author: Andiona Time: 11/12/2012 20:51
Thank You All For Correction & Encouragement. Author: ddavid Time: 12/12/2012 22:07
This first-winter thrush was still present at SKAR this afternoon.
I wonder if anyone has any further ideas on its identification given the thoughtful comments already made.
David
[ Last edited by ddavid at 12/12/2012 22:10 ] Author: brendank Time: 12/12/2012 22:09
Did anyone see the underwing coverts? That would settle the issue. Author: ddavid Time: 12/12/2012 22:18
Brendan
What is the difference in colour between the underwing coverts of Eye-browed & Brown-headed Thrush? What is your reference for this difference?
David Author: brendank Time: 12/12/2012 22:26
Brazil shows the underwing coverts of Brown-headed Thrush being decidedly pale while Eyebrowed is greyish. Author: ddavid Time: 12/12/2012 22:46
Many thanks.
I've checked Brazil and you're right: there is a clear difference.
However, I'm not sure how useful this difference (assuming it is accurate)is under actual field conditions. Must be very difficult to see & assess acurately given the normal shyness of thrushes.
David Author: brendank Time: 12/12/2012 22:54
It turns out I actually have a photo of a Brown-headed Thrush in flight (taken at Po Toi) but it doesn't match Brazil at all!
For me, this is a Brown-headed Thrush. The extent and depth of orange across the breast and up towards the head is too great for an Eyebrowed. And Brown-headed can have white markings below and behind the eye - here is one from February 2006 on Po Toi
But this one from this year I'm not so sure. Originally I called it Brown-headed but now I've settled for Eyebrowed
Author: kkoel Time: 13/12/2012 08:36
There seems to be a lot of overlap between the extent and saturation of orange in the underparts shown by these two Thrushes such that I hesitate to conclude from the underpart color. With the head pattern, I was a attracted to the contrast between the blak lores and large white patch immediately below the eye, which is quite an Eyebrowed pattern. But it's true as Geoff says that many female type Brown-headed can approximate this pattern... Perhaps only with subtly less cotrast.
So just to raise one more point for discussion: are the calls of the two species distinguishable? This Shek Kong individual called with soft high 'tzee' notes. Author: Andiona Time: 13/12/2012 12:10
MORE PHOTOS @ SHEK KONG
Author: lpaul Time: 13/12/2012 12:57
Separation of Brown-headed Thrush and Eye-browed is straightforward as Eye-browed never has anything other than apricot(ish) coloured flanks/breast and in paler toned above. All these are obvious Brown-headed Thrushes as is the bird in the link provided by Brendan but is incorrectly labelled. Author: EricB Time: 23/12/2012 17:52
Dear Paul,
I bow to your superior knowledge and experience on this subject, but subjective colour perception can be problematic in the field. Certainly the nuances of various shades of orange (apricot ,orange, dull orange & ochre etc. ), the variability with lighting conditions and individual variation amongst individual birds can make subtleties of colour an unreliable field characteristic.
I'd value your opinion on several other aspects of these photos and their relative merits in the field.
The books I've looked have not been helpful on these matters (Thrushes-Clement and Hathway ,Advanced Bird ID Guide- Van Duivendijk and The Ripley Guide- Rasmussen and Anderton) , but perhaps I'm looking a the wrong texts and you might be in a better position to direct me to other books that might shed more light on the subject or share your personal experience on the questions relating to this 1st winter bird from Shek Kong.
Q1.Is the dark upper mandible helpful in the differentiation of Eye Browed from Brown headed in 1st winter plumage?
Q2.Is the scalloped undertail coverts helpful in the differentiation of Eye Browed from Brown headed in 1st winter plumage?
Q3.Can you sex the individual in Andy's images?
Q4.Duivendijk states that the 'pale underwing , underwing coverts are pale-brown-grey' are an important key feature of Eye browed Thrush.Would you agree that Brown breasted underwing coverts are
consistently darker?
Q5.I'm assuming that Black breasted (T. Dissimilis) and Izu Island Thrush (T. Celaenops) are pretty poorly described in 1st winter plumage ( and obviously might only occur with a wide stretch of the imagination), but do you know of any features which might help you exclude these species?
Many thanks your informed opinion.
With kind regards,
Eric
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