Zoothera Thrush ID, Guangxi, China (1 Viewer)

[Barbets48]

Observed a single Scaly/White's/Amami Thrush in Baise, Guangxi China this month. Feeding on park lawn.
I'm aware that these species are extremely difficult to separate in the field, and I have browsed through a previous discussion here on Birdforum: White's or Scaly Thrush Taiwan

Wondering whether there can be any determination or best guess based on this location? Here are a few photos and a video clip in case any plumage marks or feeding behavior may serve helpful, though I know the quality may not be detailed enough. All are of the same bird.

Thanks,
Mike

 

[johnallcock]

It's most likely to be White's, which is a winter visitor to southern China.

There is a population of Scaly in the mountains of central China and as far as I know it's unclear whether these could occur more widely in southern China in winter. I've had previously discussions about birds in Hong Kong, Guangdong and Guangxi but none have been confirmed as Scaly. All birds trapped in Hong Kong have been White's. Personally I'm not sure how to separate Scaly from White's based on photos, but I have been told that this should be possible.

As far as I know there's no sign of Amami occurring anywhere outside the breeding range, so I don't think you need to worry about that.

 

[Barbets48]

It's most likely to be White's, which is a winter visitor to southern China.

There is a population of Scaly in the mountains of central China and as far as I know it's unclear whether these could occur more widely in southern China in winter. I've had previously discussions about birds in Hong Kong, Guangdong and Guangxi but none have been confirmed as Scaly. All birds trapped in Hong Kong have been White's. Personally I'm not sure how to separate Scaly from White's based on photos, but I have been told that this should be possible.

As far as I know there's no sign of Amami occurring anywhere outside the breeding range, so I don't think you need to worry about that.

Thanks John. Your concise and clear explanation is very helpful!

 

[Grahame Walbridge]

It's most likely to be White's, which is a winter visitor to southern China.

There is a population of Scaly in the mountains of central China and as far as I know it's unclear whether these could occur more widely in southern China in winter. I've had previously discussions about birds in Hong Kong, Guangdong and Guangxi but none have been confirmed as Scaly. All birds trapped in Hong Kong have been White's. Personally I'm not sure how to separate Scaly from White's based on photos, but I have been told that this should be possible.

As far as I know there's no sign of Amami occurring anywhere outside the breeding range, so I don't think you need to worry about that.

Like John I believe this is most likely White's. Further, I would have thought it likely that nominate dauma in SC China, in common with other parts of its range, vacates in winter, in this instance, probably to northern mainland SE Asia, or least, that is the common thinking.

Field identification has been the topic of much debate, particularly since the split and is clearly challenging. There is no overlap in size (not that's much help here) White's is the larger, with a longer bill and wing. Plumage differences quoted in literature (compared to Scaly) include stronger white eyeing, stronger malars, paler, streaked ear coverts and heavier-scaled, paler (less warm), upper parts. These are only average differences and, consequently, open to interpretation when faced with a bird in the field.

Now, looking at the OP, although the images are not the best quality (not a criticism Mike) the bird looks better for White's IMHO, based on a combination of face pattern, upper part tone and structural features, including long bill and long pp.

Grahame

 

[andyb39]

I also think it's more likely to be White's - the general rather dull-brown upper part coloration, bill size and shape and proportions, including the primary projection, seem to fit it better. It seems to lack the golden back scales and bronze tones of Scaly on the flight feathers, and there's quite a distinct auricular crescent. However, these characters are probably rather variable and the bird photographed by Michael Hurben in Kunming looks rather like yours: Media Search - eBird and Macaulay Library. I don't know if there are any images of birds from the breeding population in central China mentioned by John and it's possible they may differ from these presumably Himalayan birds seen in Yunnan in winter.

Did you get any images in flight? It may be possible to count the rectrices and confirm the identity (IIRC the discussion in the thread you linked in your first post established that White's shows 14 and Scaly only 12).

 

[Grahame Walbridge]

However, these characters are probably rather variable and the bird photographed by Michael Hurben in Kunming looks rather like yours: Media Search - eBird and Macaulay Library. I don't know if there are any images of birds from the breeding population in central China mentioned by John and it's possible they may differ from these presumably Himalayan birds seen in Yunnan in winter.

Did you get any images in flight? It may be possible to count the rectrices and confirm the identity (IIRC the discussion in the thread you linked in your first post established that White's shows 14 and Scaly only 12).

Hmm, that looks more like a White's IMO Andy-returning migrant perhaps?

The tail feather feature is one for in-the-hand examination which is why I did not mention it earlier.

Grahame.

 

[andyb39]

Hmm, that looks more like a White's IMO Andy-returning migrant perhaps?

The tail feather feature is one for in-the-hand examination which is why I did not mention it earlier.

Grahame.

I was thinking that too. Maybe I should report it for review.

Point taken about the tail feather count.

 

[johnallcock]

I don't know if there are any images of birds from the breeding population in central China mentioned by John and it's possible they may differ from these presumably Himalayan birds seen in Yunnan in winter.

I don't know of any pictures, sorry. It can be a difficult species to track down and the distribution and taxonomy in China seems not to be fully resolved from what I've heard, and is further confused by the presence of migrant White's.

Useful feedback from Grahame on ID tips. I'll keep a look out in Hong Kong, but they've been tricky to see here in the last couple of winters.

 

[Grahame Walbridge]

I don't know of any pictures, sorry. It can be a difficult species to track down and the distribution and taxonomy in China seems not to be fully resolved from what I've heard, and is further confused by the presence of migrant White's.

Useful feedback from Grahame on ID tips. I'll keep a look out in Hong Kong, but they've been tricky to see here in the last couple of winters.

Thanks John but I should correct one misleading statement from my original post in stating there was no overlap in size, there clearly is though White's averages slightly larger, but what I should have said is that there is no overlap in wing lengths; White's 155-178 vs Scaly 136-147. It would good to compare bill lengths as well but I cannot find any values for Scaly.

And to pick up on your point regarding unresolved taxonomy issues, jalid already raised this in relation to the resident form found in Taiwan, see Mike's linked Taiwan thread in his OP. Further, I suggest listening to these song recordings and note, in particular, how very different the first two sound, the bird in Taiwan closer to White's.

XC489637 Scaly Thrush (Zoothera dauma) dauma from Uttarakhand, India

https://ebird.org/checklist/S22538162 dauma from Tam Dao NP, Vietnam

https://ebird.org/taiwan/checklist/S24631202 Taiwan (also note what appears to be a wing length for the trapped bird).

And White's Thrush for comparison XC571408 White's Thrush (Zoothera aurea)

Grahame