Two Warblers ID help, please. Shanghai, October (1 Viewer)

[Hainan on the fly]

Down to the Warblers from my last outing. Always wish I had both a better camera and more skill when looking at these birds. As always, any and all comments are welcome and greatly appreciated.

I'm thinking the first bird just might be Manchurian Bush Warbler but I'm a little confused as some of the pictures I'm seeing online show a more rufous colored bird. Plus the beak seems a little small on my bird.

Second bird seems to fit Yellow-browed Warbler but I'm just not experienced enough to be overly confident in that ID.

Thanks,

Brian

 

[andyb39]

As Japanese Bush Warbler is a vagrant in Shanghai, I'm going along with Manchurian for the 1st bird. I also agree with Yellow-browed for the 2nd.

 

[HouseCrow]

I must admit I never really looked at Manchurian before. But I have been looking at quite a few Japanese Bush Warblers.
In migration periods* is there a way to name it a def. Manchurian? Ebird says about Japanese and Manchurian: "All but indistiguishable from Japanese Bush Warbler"

just curious,
cheers,
G erben

*sorry for bringing this up time and again.

 

[andyb39]

I must admit I never really looked at Manchurian before. But I have been looking at quite a few Japanese Bush Warblers.
In migration periods* is there a way to name it a def. Manchurian? Ebird says about Japanese and Manchurian: "All but indistiguishable from Japanese Bush Warbler"

just curious,
cheers,
G erben

*sorry for bringing this up time and again.

Manchurian looks a bit warmer and the underside of the tail looks whiter, perhaps. I don't think these are reliable differences though. It seems male Manchurian is noticeably larger than Japanese, females not so much.
I expect they're best separated on voice and range. It seems Japanese is a rare visitor to coastal China and regular in winter in Taiwan, and has been recorded in Shanghai. I'm not sure how they're identified on the mainland.

 

[Hainan on the fly]

As Japanese Bush Warbler is a vagrant in Shanghai, I'm going along with Manchurian for the 1st bird. I also agree with Yellow-browed for the 2nd.

Excellent! Thanks! Good to know that JBW is a vagrant in Shanghai

 

[Hainan on the fly]

I must admit I never really looked at Manchurian before. But I have been looking at quite a few Japanese Bush Warblers.
In migration periods* is there a way to name it a def. Manchurian? Ebird says about Japanese and Manchurian: "All but indistiguishable from Japanese Bush Warbler"

just curious,
cheers,
G erben

*sorry for bringing this up time and again.

Good point. Thanks for bringing it up!

Brian

 

[MacNara]

Just to be clear: I am not confirming or denying the ID of Hainan's bird - I have never seen Manchurian BW.

I'm attaching a few pictures of Japanese BW for comparison, that's all.

I agree with H that his bird seems pale and less red than some birds online. If you compare with my JBWs, then the overall colouring sticks out as different - JBW seems generally much greener on the back, plus there usually seems to be a contrast between the back and the head in JBW. Also the black eyeline seems stronger in front of the eye on the JBW photos I've looked at whereas it's essentially missing in Hainan's bird.

The first photo is just a fairly close-up shot from February. The second photo is a bird in essentially the same pose as Hainan's bird, just for comparison. Photos one and two were taken a week apart but in essentially the same spot, so could be the same bird. The third of my photos was taken on October 28, so essentially the same day as Hainan's photo, just out of interest.

By the way, if you darken Hainan's photo - see my fourth photo below - it seems to show the reddish cap which in both books and online seems to be a feature of Manchurian/Korean/borealis BW compared to JBW.

Andy, are you sure that JBW on the most recent definitions is actually a vagrant to Shanghai? The latest splits still seem quite unclear to me - my most recent Japanese book (first edition 2017) still has Korean Bush Warbler as a ssp of JBW. But as far as I can make out the former canturians ssp of Korean BW (a/c Mark Brazil) has been moved to JBW and the borealis ssp is the new Manchurian. Basically, JBW new-definition seems to be now a Japanese localised species, so I don't see why it would be in Shanghai.

 

[andyb39]

Just to be clear: I am not confirming or denying the ID of Hainan's bird - I have never seen Manchurian BW.

I'm attaching a few pictures of Japanese BW for comparison, that's all.

I agree with H that his bird seems pale and less red than some birds online. If you compare with my JBWs, then the overall colouring sticks out as different - JBW seems generally much greener on the back, plus there usually seems to be a contrast between the back and the head in JBW. Also the black eyeline seems stronger in front of the eye on the JBW photos I've looked at whereas it's essentially missing in Hainan's bird.

The first photo is just a fairly close-up shot from February. The second photo is a bird in essentially the same pose as Hainan's bird, just for comparison. Photos one and two were taken a week apart but in essentially the same spot, so could be the same bird. The third of my photos was taken on October 28, so essentially the same day as Hainan's photo, just out of interest.

By the way, if you darken Hainan's photo - see my fourth photo below - it seems to show the reddish cap which in both books and online seems to be a feature of Manchurian/Korean/borealis BW compared to JBW.

Andy, are you sure that JBW on the most recent definitions is actually a vagrant to Shanghai? The latest splits still seem quite unclear to me - my most recent Japanese book (first edition 2017) still has Korean Bush Warbler as a ssp of JBW. But as far as I can make out the former canturians ssp of Korean BW (a/c Mark Brazil) has been moved to JBW and the borealis ssp is the new Manchurian. Basically, JBW new-definition seems to be now a Japanese localised species, so I don't see why it would be in Shanghai.

View attachment 1412574View attachment 1412575View attachment 1412576 View attachment 1412579

No, I'm not sure! I was going by this; Japanese Bush Warbler - Shanghai Birding 上海观鸟 and this: Manchurian Bush Warbler - Shanghai Birding 上海观鸟. Based on the latter article, the OP bird should be ssp. canturians.

I understood that JBW isn't restricted to Japan, but is also present in the Philippines, and in summer "can also be found in Manchuria, Korea and central China". Is this description out of date and does it actually refer to Manchurian? It's these birds which are supposed to occur in Taiwan and on the coast of the mainland in winter. If eBird is anything to go by, JBW's breeding range only extends to Korea.

eBird has two images of putative JBW from Shanghai: Media Search - eBird and Macaulay Library. The 2019 sighting comes with an audio recording, which sounds like it was made near one of the city's airports! https://ebird.org/checklist/S61918685. That bird does look a bit JBW-ish.

You seem to be right about the coloration of Brian's bird, which also looks distinctly bulkier than those in your images. There was a JBW here a while back which also looked distinctly greenish on the back - quite Aberrant-like.

 

[MacNara]

Hi Andy.

As I said, I'm confused about the categorization of these birds.

In my copy of Brazil, 'Birds of East Asia', I have a hand-written note that says that ssp canturians of his Korean Bush Warbler has been moved to JBW in 2012 and that the remaining borealis has been renamed Manchurian BW. I can't remember why I made this note or what my source was, but I don't make notes like this often and certainly not without a (presumed by me) authoritative source.

However, I see from Birds of the World that the binomial for MBW is Holornis canturians, so I guess whatever my source was didn't win out, and canturians is back in Manchurian/Korean which makes me wonder why they changed the English name. I had assumed that the form commonly found in Korea was canturians, and that the re-naming was because if the Korean form had been moved to C. diphone, then a new name was necessary for the remaining borealis, hence Manchurian.

I think your description "can also be found in Manchuria, Korea and central China" must (mostly) refer to MBW and not JBW.

Below, I attach distribution maps for JBW and MBW from Birds of the World. I hope this counts as fair use of their intellectual property.

I agree that the birds you link to from eBird look like JBW. However, I wonder about the recording. I like music, but am very unmusical in terms of being able to pick up subtle differences. For several years, at my local spot, I have recorded Phylloscopus warblers 'zitting' in the hopes of getting a Japanese Leaf Warbler (NB 'Leaf') as opposed to a Kamchatka Leaf Warbler (which are common in autumn and spring, year in, year out). A couple of years ago, I managed to catch a JLW with photos and a recording which an expert friend confirmed (also, the bird was several weeks earlier than KLW would normally be). But although my friend could tell the difference of the 'zit' between these two species, I couldn't really do so.

However, it seems to me that JBW and MBW will also have similar but not exactly the same 'zits' and to my ear, the zit of the recording you link to sounds like but not the same as the JBW whose voice I attach (mine seems harsher, stronger, and is typical for birds around me (i.e. I haven't picked a particularly extreme example)). To me the JBW 'zit' sounds just like the sound that is printed as 'tsk!' in comics. Anyway, it's offered here just as is.

PS: Best to R and K

Your linked zit:

https://ebird.org/checklist/S61918685

My JBW zit:

View attachment 171026 Uguisu.MP3

 

[Hainan on the fly]

Awesome conversation! You are both obviously more experienced than I, so ........ I will just pull out the popcorn and enjoy the conversation.

Really appreciate your insights!

Brian

 

[andyb39]

Awesome conversation! You are both obviously more experienced than I, so ........ I will just pull out the popcorn and enjoy the conversation.

Really appreciate your insights!

Brian

Hi Andy.

As I said, I'm confused about the categorization of these birds.

In my copy of Brazil, 'Birds of East Asia', I have a hand-written note that says that ssp canturians of his Korean Bush Warbler has been moved to JBW in 2012 and that the remaining borealis has been renamed Manchurian BW. I can't remember why I made this note or what my source was, but I don't make notes like this often and certainly not without a (presumed by me) authoritative source.

However, I see from Birds of the World that the binomial for MBW is Holornis canturians, so I guess whatever my source was didn't win out, and canturians is back in Manchurian/Korean which makes me wonder why they changed the English name. I had assumed that the form commonly found in Korea was canturians, and that the re-naming was because if the Korean form had been moved to C. diphone, then a new name was necessary for the remaining borealis, hence Manchurian.

I think your description "can also be found in Manchuria, Korea and central China" must (mostly) refer to MBW and not JBW.

Below, I attach distribution maps for JBW and MBW from Birds of the World. I hope this counts as fair use of their intellectual property.

I agree that the birds you link to from eBird look like JBW. However, I wonder about the recording. I like music, but am very unmusical in terms of being able to pick up subtle differences. For several years, at my local spot, I have recorded Phylloscopus warblers 'zitting' in the hopes of getting a Japanese Leaf Warbler (NB 'Leaf') as opposed to a Kamchatka Leaf Warbler (which are common in autumn and spring, year in, year out). A couple of years ago, I managed to catch a JLW with photos and a recording which an expert friend confirmed (also, the bird was several weeks earlier than KLW would normally be). But although my friend could tell the difference of the 'zit' between these two species, I couldn't really do so.

However, it seems to me that JBW and MBW will also have similar but not exactly the same 'zits' and to my ear, the zit of the recording you link to sounds like but not the same as the JBW whose voice I attach (mine seems harsher, stronger, and is typical for birds around me (i.e. I haven't picked a particularly extreme example)). To me the JBW 'zit' sounds just like the sound that is printed as 'tsk!' in comics. Anyway, it's offered here just as is.

PS: Best to R and K

Your linked zit:

https://ebird.org/checklist/S61918685

My JBW zit:

View attachment 1412595

View attachment 1412596View attachment 1412597

It seems the articles from Shanghai Birding are out-of-date - eBird also uses canturians for Manchurian, and shows a much more restricted range for Japanese than Brelsford suggests. Nevertheless, birds sighted in Taiwan are still recorded as Japanese, with plenty of images as evidence, and a handful of Chinese records remain, including a couple of offshore records. Some may refer to Manchurian. Xeno Canto has just one audio recording from Taiwan, a hard "tsk", and none from China.

I don't have an ear for calls either, but I agree, your tsk sounds a little harder and more insistent - within variation, though, perhaps? Many of the calls for Manchurian on Xeno Canto sound quite grating.

Regards to T from us!

 

[johnallcock]

The taxonomy of these has indeed been complicated. At the time of the split a few years ago, canturians was put into Japanese BW. I think this was on the basis of a genetic study. This was adopted by IOC and eBird. This was always a surprising result because canturians and borealis are extremely similar morphologically - we struggle to separate them even in the hand, and I'm not confident we are correct - in the field they are probably inseparable.

I think that later analysis suggested the earlier DNA results were not reliable, and canturians was combined with borealis as Manchurian BW. This makes a lot more sense (to me at least) and makes ID of most birds wintering in China easier (I'm not sure of the status of each on Taiwan).

I think the Shanghai Birding blog posts date from the time when canturians was part of Japanese and people were trying to get a handle on the occurrence of the two species in China, so these are now out of date. There may be some incorrect IDs remaining on eBird, but hopefully most (if not all) have been resolved. The ones linked earlier in post #8 do look promising for Japanese, although I've got no experience of that species - the call is also unlike the typical Manchurian call, but I have occasionally heard Manchurian giving something a bit similar.

 

[MacNara]

Thanks for a very useful post, John. From what you say, the species boundaries have gone back to what they originally were, so I wonder why they didn't revert to the former English name also. 'Manchurian' seems to be a random selection from the extreme edge of the range of this species. I'm glad to hear that my annotation in my copy of Brazil (mentioned in post#9 above) was not the result of some delusion, but was correct at the time. My two recent Japanese books (2017) both have 'Manchurian' as a ssp of Japanese BW under the name Korean Bush Warbler (maybe there's some politics involved).

A friend tells me that there is talk of splitting the Swinhoe's Snipe that migrate through Honshu from those that migrate through Okinawa. That should be fun!

 

[johnallcock]

Thanks for a very useful post, John. From what you say, the species boundaries have gone back to what they originally were, so I wonder why they didn't revert to the former English name also. 'Manchurian' seems to be a random selection from the extreme edge of the range of this species. I'm glad to hear that my annotation in my copy of Brazil (mentioned in post#9 above) was not the result of some delusion, but was correct at the time. My two recent Japanese books (2017) both have 'Manchurian' as a ssp of Japanese BW under the name Korean Bush Warbler (maybe there's some politics involved).

A friend tells me that there is talk of splitting the Swinhoe's Snipe that migrate through Honshu from those that migrate through Okinawa. That should be fun!

No, originally both borealis and canturians were included as subspecies of diphone (Japanese BW). They are now combined as a different species.
The process has been:
Japanese H. diphone (including borealis and canturians as ssp) ->
Japanese H. diphone (including canturians) + Manchurian/Korean H. borealis (borealis only) ->
Japanese H. diphone (the Japanese taxa) + Manchurian H. canturians (borealis and canturians)

I'm not sure which former name you suggest they should revert to. Clearly they can't return to Japanese BW!
I am aware that the name Manchurian is controversial, as it is often considered to relate to the period of Japanese Imperialism in China and Korea. I think this is the reason that the name Korean has been suggested for this species, but that hasn't really caught on yet, apart from the Brazil field guide. Both names are somewhat inaccurate for a species with a range extending down to the Yangtze valley.

I hadn't heard about the potential split of Swinhoe's Snipe. That would make things very tricky!

 

[MacNara]

Thasnk you John, that's all a lot clearer for me now.

 

[MacNara]

No, originally both borealis and canturians were included as subspecies of diphone (Japanese BW). They are now combined as a different species.
The process has been:
Japanese H. diphone (including borealis and canturians as ssp) ->
Japanese H. diphone (including canturians) + Manchurian/Korean H. borealis (borealis only) ->
Japanese H. diphone (the Japanese taxa) + Manchurian H. canturians (borealis and canturians)

I'm not sure which former name you suggest they should revert to. Clearly they can't return to Japanese BW!

John, I'm afraid I'm not as au fait with naming developments as many on BF. I rely on books and the internet for information, rather than specialist magazines.

I simply asumed that Brazil's 'Birds of East Asia' (2009) was using the latest generally accepted nomenclature, and not attempting to introduce a new name himself. He simply states 'formerly within JBW'. All my books still use Cettia, not Horornis, so I'll do that here for (some) simplicity.

In his book, canturians and borealis are lumped as a single species Korean Bush Warbler, Cettia canturians, with (current) canturians and borealis as ssp of this - i.e. C. canturians canturians and C. canturians borealis, with the subspecies C. canturians canturians also having a ssp English name of Manchurian BW.

Later, C. canturians canturians (i.e. Manchurian) is moved back to C. diphone (i.e. Japanese), so the remaining C. borealis gets a new binomial (not trinomial) and presumably to keep the name Korean. Then in the next move C. canturians canturians (i.e. BofEA's Manchurian) is moved back to a common species with borealis, and borealis is demoted to a ssp of C. canturians which latter also brings its name of Manchurian for the new combined species.

So my mistake or confusion was to originally think Mark Brazil was using a generally accepted nomenclature, in which case 'Korean Bush Warbler' would be the 'former English name' I referred to. But I note now that Avibase produces no hits for Korean Bush Warbler as a name used by any authority, so it looks as if Mark Brazil was trying to impose a new nomeclature by default without sufficiently warning his readers.

On top of this all my five Japanese-language books, even from as recently as 2017, lump everything under C. diphone, and use a name for these ssp which is usually translated as 'Korean' (though even this is problematic as the Chinese characters are very old and have meant different areas over the centuries). The otherwise (for me) best book, from 2017, sidesteps part of the problem by not mentioning canturians as a ssp at all but still having C. d. borealis, sakhalinensis, diphone (long-billed), restricta and riukiuensis

'Birds of the World' still says, "Taxon canturians possibly belongs with “cantans group” of H. diphone or is perhaps a separate species."

So I hope you'll excuse my confusion.

Thanks again for your really useful replies in this thread.

 

[johnallcock]

John, I'm afraid I'm not as au fait with naming developments as many on BF. I rely on books and the internet for information, rather than specialist magazines.

I simply asumed that Brazil's 'Birds of East Asia' (2009) was using the latest generally accepted nomenclature, and not attempting to introduce a new name himself. He simply states 'formerly within JBW'. All my books still use Cettia, not Horornis, so I'll do that here for (some) simplicity.

In his book, canturians and borealis are lumped as a single species Korean Bush Warbler, Cettia canturians, with (current) canturians and borealis as ssp of this - i.e. C. canturians canturians and C. canturians borealis, with the subspecies C. canturians canturians also having a ssp English name of Manchurian BW.

Later, C. canturians canturians (i.e. Manchurian) is moved back to C. diphone (i.e. Japanese), so the remaining C. borealis gets a new binomial (not trinomial) and presumably to keep the name Korean. Then in the next move C. canturians canturians (i.e. BofEA's Manchurian) is moved back to a common species with borealis, and borealis is demoted to a ssp of C. canturians which latter also brings its name of Manchurian for the new combined species.

So my mistake or confusion was to originally think Mark Brazil was using a generally accepted nomenclature, in which case 'Korean Bush Warbler' would be the 'former English name' I referred to. But I note now that Avibase produces no hits for Korean Bush Warbler as a name used by any authority, so it looks as if Mark Brazil was trying to impose a new nomeclature by default without sufficiently warning his readers.

On top of this all my five Japanese-language books, even from as recently as 2017, lump everything under C. diphone, and use a name for these ssp which is usually translated as 'Korean' (though even this is problematic as the Chinese characters are very old and have meant different areas over the centuries). The otherwise (for me) best book, from 2017, sidesteps part of the problem by not mentioning canturians as a ssp at all but still having C. d. borealis, sakhalinensis, diphone (long-billed), restricta and riukiuensis

'Birds of the World' still says, "Taxon canturians possibly belongs with “cantans group” of H. diphone or is perhaps a separate species."

So I hope you'll excuse my confusion.

Thanks again for your really useful replies in this thread.

I fully understand your confusion.
I think BoEA was first published shortly before the scientific papers looking into this taxonomy. Mark Brazil was probably aware that a split was possible, and treated them as two species in his book in anticipation of this, so the book would not be immediately out of date (this is not unusual in field guides). He presumably thought that borealis and canturians would be related as they are so similar in appearance and vocalisations. Everyone was surprised when the first DNA results were published suggesting that canturians was more closely related to diphone, but that result was initially accepted as the basis for the split and followed by major listing authorities. It was only with further work that the taxonomy was changed again.

I think the name Korean BW was first proposed in BoEA, perhaps because Brazil was aware of the potential controversy of using Manchurian. But it hasn't really caught on as a name on other lists. I find it odd that Brazil suggests Manchurian as a name for canturians, only, as this ssp doesn't occur as far north as 'Manchuria' (borealis breeds in this region).