Subject: Hybrid Black-throated x Naumann's Thrush? [Print This Page] Author: ddavid Time: 18/01/2014 18:43 Subject: Hybrid Black-throated x Naumann's Thrush?
I saw the following thrush at Mui Shue Hang this afternoon. I would be grateful for any comments on its ID.
David Author: tgraham Time: 18/01/2014 18:59
Dave
Why do you think its hybrid.? Although all the bird cannot be seen there are images on the web that look very like this bird
Can you provide more details of the location
Thanks
Graham Author: ddavid Time: 18/01/2014 19:20
I think it's a hybrid because of the orange-brownish mottling on the flanks that is visible in the 2nd photo. Pure Black-throated should, I think, show greyish streaking.
Mui Shue Hang is the park along the banks of the Lam Tsuen River 5 minutes walk from Tai Wo station at Shui Wai Village. You cross the bridge over the river and turn right into the park. The bird is anywhere on the left in the leaf litter or thicker vegetation between the entrance to the park and the turn to Mui Shue Hang Village. There are Grey-backed & Japanese Thrushes in the same area. Author: ajohn Time: 19/01/2014 16:12
I understand that this or a similar bird was seen this morning, and there was some uncertainty about whether it was Black-throated or Japanese. Unfortunately, after comparing these photos with photos of Black-throated online, I dont think the bird in these photos is Black-throated (or a hybrid with Naumann's) for the following reasons:
1. Head pattern. The contrast between the black throat and grey back does not seem to be significant enough. Black-throated is fairly pale-backed, which should contrast with a blackish throat.
2. Wing pattern. Photos of black-throated show the wing feathers to be fairly dark-centred with a narrow pale fringe. This is fairly apparent on the median and greater coverts, as well as alula, primaries and primary coverts. The Mui Shue Hang bird appears too uniform in the wings. It also appears that there are usually dark centres to the scapulars on Black-throated, which this bird doesn't seem to show. The tertials of Black-throated are often two-toned grey (outer web) and black (inner web), but these feathers are not clear on the photos.
3. Leg colour. The second photo shows this bird to be pale (pink?)-legged. Black-throated often seems darker-legged, especially males (although this is variable).
4. Flank pattern. The second photo seems to show that the bird is dark on the rear flanks, above the leg. Black-throated seems to be white or pale with well-defined streaks.
5. Structure. Overally, this bird looks to be a small thrush to me, seeming fairly dumpy and round-headed. Overall this fits the structure of Japanese whereas Black-throated looks larger and relatively smaller-headed with a flatter crown.
Having said all that, the bird doesn't seem to 100% fit Japanese thrush either, but it does seem closer to Japanese and I suspect that it is a plumage variation of this species rather than Black-throated. Author: ddavid Time: 19/01/2014 18:33
John
Thanks for the detailed analysis. I tend to agree that it's a Japanese Thrush (1st-W male?) although to me the plumage does seem confusingly atypical. It confused me anyway!
David Author: wgeoff Time: 20/01/2014 06:29
Here are three more photographs of this bird taken by Benjiman Li (thanks Benjiman) taken on Sunday
Author: Godwin-C Time: 21/01/2014 18:28
I also take the similar bird at same day / location, hope it can give more info.
[ Last edited by Godwin-C at 21/01/2014 18:32 ]
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