Hi Steve: Why did you remove your reddish bird photos? I thought they were useful and interesting.
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White's or Scaly Thrush Taiwan (1 Viewer)
- Thread starter sicklebill
- Start date
Hi Steve: Why did you remove your reddish bird photos? I thought they were useful and interesting.
RafaelMatias
Unknown member
It's a 12 rectrices tail, imo, with the 4th on the right side missing (counting outwards from the central pair). That's all I can contribute to this thread, most unfortunately
A fascinating discussion, well worth following. B Thanks, Rafael. That was my judgement exactly - 12 retrices with the blackish fourth on the right missing. The tail looks fully spread and I can't see any other places where feathers are obviously missing. I hadn't really paid attention to this when I took the photo. Also I came to birding later in life, and I'm very poor at judging fine details of primary projection, emargination, and things like that, so I lack confidence even in counting feathering.
The thing is that if this bird has only 12 retrices, then it can't be White's Thrush which is supposed to be the only (sub-) species (race toratsugumi?) in my locale and which should have 14. In fact the bird with 12 retrices is supposed to be the Amami Thrush (Zoothera major) which is an endemic resident of two small islands south of Kyushu in Japan (about 700km in a straight line from where I am). (As far as I can see from HBW and books I have, White's and Scaly both have 14 retrices.)
So, I wonder if anyone has any comments on this bird.
I attach two more photos which may or may not be the same bird, to show the overall view (unfortunately I didn't get a non-flying view of the bird I posted earlier with the tail).
Photo one is about 100m away from my original photo ten days later. Photo two is a bird in the exact same spot two years later (minus one day).
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johnallcock
Well-known member
HBW doesn't include Scaly on Taiwan because, under their taxonomy, Scaly doesn't occur on Taiwan - they consider the local breeding taxon to be a part of White's, based on vocalisations (this is explicitly stated in their text account). For HBW, White's Thrush occurs there as both a resident breeder and a winter visitor.
But this taxonomy is not universally. Others consider that the taxon breeding in Taiwan should be treated as a part of Scaly, based on the morphological and plumage differences described by Grahame. In this case, both Scaly (a resident) and White's (a winter visitor) occur on Taiwan. This was the reason for the question in the original post.
Yes, there are inconsistencies in published information regarding the distribution of these species. This is because there is not yet an agreement about the species limits in this complex, and which populations should be assigned to which species.
Thanks for this John. But part of the point is that if strongly respected sources disagree to this extent, is there any point in trying to fit particular birds into one or other of the species? Except as a part of trying to make the species boundaries clearer.
For example, do you have an opinion about Sicklebill's originally posted bird?
Or do you have an opinion about my bird and its tail? Is Grahame correct in saying that Scaly has only 12 retrices, or am I right (entirely based on books) that only Amami has this feature?
Grahame Walbridge
Well-known member
To be absolutely clear, I was referring to nominate aurea whereas the taxon that winters in Taiwan and is both resident/winters in Japan is toratugumi- see here https://www.featherbase.info/it/species/zoothera/aurea this reference states a variable number of rectrices (12-14) in the text but all the examples have 14 like nominate-see here http://lamsdell.blogspot.com/2019/10/khovd-mongolia-whites-thrush-18th.html Having only examined skins of nominate I cannot comment further.
Tail pattern of your OP bird looks better for White's IMO but it appears to have 12 rectrices so, maybe confirmation that toratugumi can have a variable number?
Mac, I passed no comment on the bird in the OP because the images were simply not good enough IMHO.
IOC's treatment https://www.worldbirdnames.org/bow/thrushes/ but as John alludes, it is very doubtful we have heard the last word on what is a very complex issue.
Grahame
Tail pattern of your OP bird looks better for White's IMO but it appears to have 12 rectrices so, maybe confirmation that toratugumi can have a variable number?
Mac, I passed no comment on the bird in the OP because the images were simply not good enough IMHO.
IOC's treatment https://www.worldbirdnames.org/bow/thrushes/ but as John alludes, it is very doubtful we have heard the last word on what is a very complex issue.
Grahame
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James Eaton
Trent Valley Crew
And even more difficult to hear! Must the most difficult cryptic species complex in Asia for a comprehensive vocal analysis, as they so rarely sing (and when they do, often pre-dawn).
Photo just too distant for me to comment on.
James
Thank you again, Grahame.
As you will have worked out, I have lived in Japan for a long time, but I have only birded for about ten years here (and on travels in Africa and Australia and elsewhere as part but usually not the main purpose of the trip). So I am an 'enthusiatic amateur' rather than 'knowlegeable expert' such as yourself and others who generously share their expertise here on BF.
I have Mark Brazil's 'Birds of East Asia' (but not the 'Birds of Japan') and various Japanese-language guides, including a beautiful illustrated (not photo) guide from 2017.
Most of these mention 12 retrices as opposed to 14 as a distinguishing feature (along with song) of Amami Thrush (Zoothera major) as opposed to White's/Scaly (which none of my Japanese guides split at species level, using 'Scaly' as the English name).
I have never before come across the Featherbase site that you linked to, but I notice that although it states 12-14 retrices for White's Thrush, the examples shown for this, and for Scaly, have, as you say, 14. Also, there is no result for Amami Thrush on the site, which may mean that they include Amami in White's. But if Amami always has 12 and White's (toratsugumi or whatever) has 14, then this would be 'wrong'.
As you say, my photo could be evidence that White's ssp toratsugumi sometimes has only 12 retrices. But (logically) it could also be that the Amami Thrush is not as localised as it is said to be. Or that there is another ssp than those currently recognised. I thought that something like the number of retrices was pretty definitive as a species marker?
Anyway, I'd be glad to hear any further comments from you or others.
[Just for general information: 'toratsugumi' in English in the books is a race of this thrush (White's or Scaly as you like) found in some parts of Japan. In Japan, toratsugumi is the name of the bird, all species - 'tora' means 'tiger' and 'tsugumi' means 'thrush'. The bare name 'tsugumi' refers to Dusky Thrush which is our common thrush in winter (none in summer), and not all thrushes have 'tsugumi' in their name.]
I took the photos down as the remark 'slighty reddish bird' in #12 was sarcastic in nature.
As Grahame's comments in #16 make no sense without them, I've put them back up, but I can't help but feel like a bit of a mug for volunteering my own intellectual property to a thread like this one.
In relation to the OP, both forms of 'XXX Thrush' are currently at Xitou in Nantou County (where the resident form has bred for the last four years at least). The eBird contributor below has both correctly identified.
https://ebird.org/checklist/S64888115
As is plainly obvious, the resident breeding form of 'XXX Thrush' (labelled 'Scaly Thrush') is deep russet-toned above, whereas (wintering) White's is yellow-golden-toned.
On the basis of this, the bird in the OP is not of the resident breeding form.
Steve
I truly apologise for the apparent sarcasm of my post, which was not intended. In my experience, photos of this bird vary a lot in colour tone depending on whether they are in shade or not and what the surrounding light is like (sunny, cloudy or whatever). To me, the colour variation you mentioned didn't seem so significant (I haven't come across this in my books or online discussion, HBW says Scaly is 'A large, golden-olive to yellowish-looking thrush'), but now that you have explained it, and with the e-Bird link you give, another factor is added to data for this/these species.
I welcome Steve photos again.
From a birding perspective, all we need is post#11: the opinion of a local birder sending fine photos of two different taxa, whatever the names.
While waiting for decisions on this complex group I would tick White's, and recommend my tour guide for a little more training, as well as a better painting for the taiwanese breeding form in the books.
From a birding perspective, all we need is post#11: the opinion of a local birder sending fine photos of two different taxa, whatever the names.
While waiting for decisions on this complex group I would tick White's, and recommend my tour guide for a little more training, as well as a better painting for the taiwanese breeding form in the books.
Grahame Walbridge
Well-known member
Mac, Scaly has has 12 rectrices, the only other member of the White's-Scaly complex to show 14 is horsfieldi (Indonesia) which does concern us here. If OBI were not currently down I could show you an image of a Scaly showing 12 rectrices.
Regarding the Featherbase link I provided, I think it's misleading since it relates to White's (species) but only illustrates toratugumi at sub-species level so the variation (12) may not be correct. Or could it relate to Amami? I don't know, but its certainly confusing.
The Featherbase link to Scaly is even more misleading since it illustrates White's, rather than Scaly https://www.featherbase.info/da/species/zoothera/dauma the top bird (complete) is a White's from Mongolia, presumably pre-split back in 2003.
And to be clear, I am now uncertain of the ID of your OP (in flight) unless it is missing 3 rectrices!
Grahame
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Grahame, none of the sources that I have seen which split Scaly and White's (species or sub-species) mention this difference.
Mark Brazil and my Japanese language books specifically mention the 12 retrices as a species-identifying feature of endemic (and resident in two small islands) Amami Thrush, which even Brazil ('East Asia' but maybe not 'Japan' which I don't have) makes a separate species, and which the Japanese books, even though they don't make a fuss about White's versus Scaly, give as a sub-species (O-toratsugumi, Large Scaly/White's Thrush). Do you have a source, whether online or not, which mentions this for Scaly?
Or does anyone else reading have a reference for this?
Even so, if the bird I posted has only 12 retrices, then it isn't White's - isn't that the case? Or can even a sub-species vary in such a significant feature? Or is ssp toratsugumi a ssp of Scaly or Amami, not of White's?
Grahame Walbridge
Well-known member
'Thrushes', Clement & Hathaway (2000)
'Birds of South Asia: The Ripley Guide, Rasmussen & Anderton (2012)
'Handbook of Western Palearctic Birds', Shirihai & Svensson (2018)
Grahame
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Thank you for these references. Unfortunately they are a bit expensive for me given that they mostly deal with areas for which I am not likely to need specialist guides.
Looking at them on Amazon, the Western Palearctic book apears to stop well short of east Asia (up to the Urals, and Iran, but not further east), and the Thrushes book index shows White's/Scaly as a combination suggesting that they do not differentiate. The 'Birds of South Asia' is published by Lynx which is the HBW company, so I'm surprised that they don't co-ordinate (as I said in another post, HBW gives the 12 versus 14 retrices difference as a distinction between Amami and White's, but is silent on Scaly).
So, I wonder if the 12 retrices figure is arrived at by including Amami Thrush as a variation rather than a species in its own right. As I have said, Amami Thrush is supposed to be distinguished by its 12 retrices as opposed to 14, and is supposed to be endemic on a pair of small islands just south of Kyushu and not far north of Taiwan. But I wonder after reading comments on this thread if 'White's' and 'Scaly' and various subspecies might actually be linked by this supposed isolate?
Or do these guides that you name state that Scaly throughout its range always has 12 retrices?
Thank you for your earlier comment that you are 'now uncertain of the ID of [my] OP (in flight) unless it is missing 3 rectrices!' It still seems to me that the bird whose tail I posted should not be 'simple' White's. And Steve's bird from Taiwan also looks quite different from related ssp, given that I now realise that the colour is 'real' and not a photo artefact for which error in interpretation I have tried to apologise for to Steve in a previous post.
Maybe, Grahame, you could use your expertise to contact HBW or others to put some of this information uncertainty in their descriptions.
It's bedtime here. But, in any case, I think I've exhausted any contribution I can make to this thread. I look forward to reading more comments from others, however.
To end on an off-topic happy note: the weather where I am this week has been gloomy, but this morning I went out to my local patch for an hour - and there were about 100 waxwings, mostly Japanese, but a couple of Bohemian feeding on red berries in someone's garden, just a few metres away. Beautiful!
Goodnight all!
johnallcock
Well-known member
Thank you for putting the photos up again Steve. I didn't see them previously, and these (and the eBird list you also linked) are very informative.
I've always been confused about the separation of White's and Scaly, and this thread has been very useful, especially seeing the photos. I've never (definitely) seen Scaly so haven't been clear how they differ.
Here in Hong Kong, White's is a regular winter visitor (in variable numbers). Scaly has never been recorded, although I do wonder about the possibility of birds coming here from the mountains of central China (one reason for my interest in knowing how to identify them!).
Following the discussion here, I checked the details in our ringing database. Some birds have had the number of tail feathers recorded and, although most have 14, we have had at least one bird trapped with 12 tail feathers. Maybe this supports the idea that toratugumi can have a variable number of tail feathers.
We have also trapped birds previously with short wing lengths, much shorter than the range given by Svensson for nominate aurea. I will need to read up more about the biometrics of toratugumi to see how these compare, or to check whether these could have been a completely different taxon.
Hi Steve,
I repeat my apology for appearing to diss your post #11 with photos of a pale ‘White’s’ and a more russet ‘Scaly’. As I said when I asked you later why you had removed them, I thought they were interesting and useful. Like others, I am glad you have put them back up.
As I said, one reason why I dismissed the difference between the two birds as just one of them was ‘slightly reddish’ was that I thought this could be just a difference of lighting conditions.
But another reason was that I thought I had seen similar differences in my area. Since the books I have tell me that I have just the one (sub-) species in my area (Zoothera dauma toratsugumi) or maybe two (Z. d. aurea), the assumption would be that this colour difference was just individual variation.
But because of your post, I looked back through my photos of maybe six or seven individuals over the same number of years. I found two birds that looked more russet than the others.
When I compared these with your White’s / Scaly pair, I noticed that while both your birds have a white vent, the ‘Scaly’ has russet/brown streaking continuing down from the belly to mark the vent off from the belly (which is white with black streaking). One of my birds has the same feature, but the other has does not. But both of my ‘somewhat russet’ birds also have russet on the chest below the throat, whereas the other birds do not. The bird with the vent marked off also has more strongly russet (not beige) on some wing feather tips
I wonder if anyone thinks one or both of these russet intrusions could be significant as species or sub-species markers? And if so, maybe the (sub-species) are more spread up and down the continent than the books tell us?
Anyway (all from Nara Prefecture, Japan; all February or March):
Photos 1 & 2: (different birds) pale and white
Photo 3: more russet, and with some russet on chest but a white belly and vent
Photos 4 & 5 (same bird): here there is russet on the chest, and the vent is also marked off by a russet intrusion , similar to Steve’s ‘Scaly’ in my opinion. Could it be 'Scaly'?
The bird in photos 4 and 5 stayed for a couple of months in a small area of park wedged between houses and a museum of traditional buildings - not busy, but not very quiet either. It was easy to photograph from a few metres away and wasn’t bothered about people very much (there was a knee-high barrier between its patch and the path from which it could be photographed). This is quite different from all the other birds in this complex which I have seen.
Anyway, comments appreciated.
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Grahame Walbridge
Well-known member
Mac, the taxon of Scaly that occurs in Japan is iriomotensis which, according the Brazil's latest, is restricted to Yaeyama Is. (Iriomote) which is close to Taiwan, where it is a rare resident. Given its proximity to Taiwan it's plausible that it's the same taxon that is resident there. The chances of a migrant nominate dauma occurring in Japan are extremely unlikely-nil IMO.
Regarding your images see no reason why they are not all toratugumi (White's), the 'differences' you point out could be explained by lighting, individual variation not to mention the quality of the image.
White's https://www.shanghaibirding.com/tag/whites-thrush/
and Scaly taxon xxxx from Taiwan https://macaulaylibrary.org/asset/189319701#_ga=2.242457090.1255962709.1582957897-477926386.1582957897
Grahame
Regarding your images see no reason why they are not all toratugumi (White's), the 'differences' you point out could be explained by lighting, individual variation not to mention the quality of the image.
White's https://www.shanghaibirding.com/tag/whites-thrush/
and Scaly taxon xxxx from Taiwan https://macaulaylibrary.org/asset/189319701#_ga=2.242457090.1255962709.1582957897-477926386.1582957897
Grahame
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You seem again to be relying on 'authorities'. You seem to be assuming that the species and their taxons have been fixed along with their distribution. But I thought that species differentiation and distribution was precisely what was being discussed here.
I'm pretty sure Mark Brazil hasn't done any personal research on White's / Scaly since his 'Birds of East Asia' and so if his new book has a different set of species and distribution, then he is himself relying on authorities - other people's opinion about something which is undecided and on which he is not necessarily better informed than many others. And I thought we were all in agreement that for this / for these species this is by no means decided. (As I pointed out in an earlier post, Handbook of Birds of the World seems to be quite mixed up about this species compex and its distribution.)
Although you say that Scaly has twelve tail feathers and White's fourteen (as I said, I can't afford the references you give, but you are free to post here a screenshot of the relevant paragraphs from those books if it is as definite as you say, rather than simply the result of mixing Amami Thrush with one of the other groups), you also say that the toratsugumi ssp of White's (or Scaly, if you don't differentiate them as Japanese authorities don't) can have 12 or 14.
But it seems to me strange that a single species and even moreso a single race of a sub-species can have different numbers for a feature as basic as the tail.
As I said before, Japanese authorities have 12 retrices as a distinguishing feature of Amami Thrush which I thought all were agreed on making its own species (and 14 on Scaly/White's).
Well, Grahame, lighting and individual variation was what I originally said about the differences between Steve's images of 'Scaly' and 'White's', but that was rejected, as I later thought, correctly; but if you would like to suggest his two photos are the same bird, or alternatively pick out what is distinctive in his two, but not mine, that would be great.
And I picked photos where the lighting was clear. And the rufous parts seem clearly different to me, especially the stretch down to the vent, and similar to the differences between Steve's two birds.
And all the images were 3000 pixels wide when taken, but reduced for BF, so I don't think 'quality' of the photo is relevant. Maybe you are just looking on a phone? But on my 27" screen, there's a lot of difference.
I'm not sure I see the point of this link. As far as I can see, it's just pale birds. The bottom one is just a pale bird. The top one seems to have a little rufous on the throat (like my photo three, but weaker), but it doesn't have the rufous bar down from the belly marking off the vent that I have tried to point out in Steve's 'Scaly' and my bird 4 & 5. And nor does it have the rufous on the tertial tips that I mentioned and now I have marked in green on the attached photo.
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johnallcock
Well-known member
I think that the photos #4 & 5 added by Mac do look interesting, and don't have the bulky body/small head look that I associate with White's, as well as looking a shade darker. I'm not sure what to make of that - it may be taxonomically relevant but could equally be due to age, sex, individual variation, lighting, posture, etc.
As a word of caution to Mac, I've looked in the past at some of the features you're highlighting here when looking at photos of birds in south China (as well as other features eg shape of the black bars on the underparts). They can seem promising when comparing one or two birds, but in my experience it can start to become a little less clear-cut when looking at a larger series of photos. This is a very variable species.
I don't think you can criticise Grahame for relying on 'authorities'. He is using published sources based on the best information available to us at the moment. This is clearly a very difficult species complex to resolve taxonomically, given the difficulty of seeing and hearing birds, the presence of isolated taxa on various islands/mountain ranges and the overlap in range between resident and migratory taxa. We're not going to be able to resolve it here. Until there is a clearer resolution of the situation, I'm afraid we may have to rely on the imperfect taxonomy that the authorities are currently using.
As a word of caution to Mac, I've looked in the past at some of the features you're highlighting here when looking at photos of birds in south China (as well as other features eg shape of the black bars on the underparts). They can seem promising when comparing one or two birds, but in my experience it can start to become a little less clear-cut when looking at a larger series of photos. This is a very variable species.
I don't think you can criticise Grahame for relying on 'authorities'. He is using published sources based on the best information available to us at the moment. This is clearly a very difficult species complex to resolve taxonomically, given the difficulty of seeing and hearing birds, the presence of isolated taxa on various islands/mountain ranges and the overlap in range between resident and migratory taxa. We're not going to be able to resolve it here. Until there is a clearer resolution of the situation, I'm afraid we may have to rely on the imperfect taxonomy that the authorities are currently using.
