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Sakhalin or Pale Legged Leaf Warbler? (1 Viewer)
- Thread starter Kandahar
- Start date
On distribution, in that location it should be Sakhalin LW not Pale-legged. The Japanese names for the split species are Ezo (Hokkaido) LW and Amur (also Northern) LW, as the former comes through Japan and breeds in the north of Japan and areas further north of there; while the latter is regarded as a continental species that is only a rare vagrant to Japan.
However, as House Crow says, it seems that they can only reliably be told apart on song ('Birds of East Asia' says the calls are basically the same). The song of Sakhalin is described in BofEA as 'hee-stoo-kee' but friends describe it better as 'rusty old bicycle'.
However, as House Crow says, it seems that they can only reliably be told apart on song ('Birds of East Asia' says the calls are basically the same). The song of Sakhalin is described in BofEA as 'hee-stoo-kee' but friends describe it better as 'rusty old bicycle'.
In that location - Nanko Bird Sanctuary in Osaka - the bird will be on migration. According to BofEA, Pale-legged LW 'breeds only in continental East Asia', and is a 'rare migrant in Japan (common in Korea)'.
The only Japanese book I have which goes into detail goes with my (educated) guess that these 'rare' migrants are on Hegura Island and the west of Kyushu - the book specifies this - Hegura, Fukuoka and Nagasaki Prefectures are mentioned, and even here it is likely to be offshore islands such as Tsushima and the Goto Islands (both legally in Nagasaki Prefecture though some are closer to Fukuoka or even Korea geographically than to Nagasaki city) which are directly south of Korea.
Osaka is in the middle of Japan, nowhere near the west coast, so these rare migrating vagrants are very unlikely to be there. However, unless you hear the song, I suppose it is impossible to be absolutely certain, and I suppose also that with the ID difficulty some Pale-legged migrating birds might be overlooked.
But without song evidence to the contrary, Sakhalin is much more likely anywhere (including the west coast) and overwhelmingly more likely in Osaka.
The only Japanese book I have which goes into detail goes with my (educated) guess that these 'rare' migrants are on Hegura Island and the west of Kyushu - the book specifies this - Hegura, Fukuoka and Nagasaki Prefectures are mentioned, and even here it is likely to be offshore islands such as Tsushima and the Goto Islands (both legally in Nagasaki Prefecture though some are closer to Fukuoka or even Korea geographically than to Nagasaki city) which are directly south of Korea.
Osaka is in the middle of Japan, nowhere near the west coast, so these rare migrating vagrants are very unlikely to be there. However, unless you hear the song, I suppose it is impossible to be absolutely certain, and I suppose also that with the ID difficulty some Pale-legged migrating birds might be overlooked.
But without song evidence to the contrary, Sakhalin is much more likely anywhere (including the west coast) and overwhelmingly more likely in Osaka.
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Thanks for the comments everyone.
Actually Nanko is one of the few places on the mainland where you may see Pale Legged Leaf Warblers for some reason known only to them. Osaka is on the coast - it's a major port city and Nanko is next to the port. Leaf Warbler migration through Osaka; Japanese Leaf, Eastern Crowned, some Kamchatkas and Sakhalins through Osaka Castle. Most of the Kamchatkas and Sakhalins (with the occasional Pale Legged) through Nanko. Apart from the Eastern Crowned everything has to be identified by call. I was thinking this one was distinctive enough to identify by plumage
Actually Nanko is one of the few places on the mainland where you may see Pale Legged Leaf Warblers for some reason known only to them. Osaka is on the coast - it's a major port city and Nanko is next to the port. Leaf Warbler migration through Osaka; Japanese Leaf, Eastern Crowned, some Kamchatkas and Sakhalins through Osaka Castle. Most of the Kamchatkas and Sakhalins (with the occasional Pale Legged) through Nanko. Apart from the Eastern Crowned everything has to be identified by call. I was thinking this one was distinctive enough to identify by plumage
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Hi Kandahar,
I'll have to bow to your superior knowledge of Pale-legged at Osaka Castle and Osaka Nanko. If they do pass through, then they would have to be identified by song (BofEA says the calls, the tsits are not distinguishable).
But as well as the book I mentioned which specifies the western coast, I checked on the 'Birding, Kyoto, Kansai and Japan' blog. There is no entry for Pale-legged as such, but here is one comment which occurs on a report of a trip to Hegurajima in 2020:
It's true that Osaka is on a coast but it's not the coast which is mentioned by the book and blog I have quoted. Birds flying south for the winter from the Pale-legged LW breeding grounds on the continent to wintering grounds in southern China and south will logically end up on the western coast of Japan and its islands. But they would have to take a huge eastwards detour to end up in Osaka. But some birds may of course take a route over the sea of Japan and then the mountains of Japan to end up in Osaka.
If Pale-legged can be identified on appearance alone from your photo, then it's far above my competence. Unfortunately the two people I can think of who might be willing to comment on this are not active on Bird Forum at the moment.
HTH
I'll have to bow to your superior knowledge of Pale-legged at Osaka Castle and Osaka Nanko. If they do pass through, then they would have to be identified by song (BofEA says the calls, the tsits are not distinguishable).
But as well as the book I mentioned which specifies the western coast, I checked on the 'Birding, Kyoto, Kansai and Japan' blog. There is no entry for Pale-legged as such, but here is one comment which occurs on a report of a trip to Hegurajima in 2020:
Again, the location for Pale-legged when singing and identifiable is Hegura, Mishima Island (Yamaguchi, opposite Korea) and Tsushima which I mentioned above and which is nearer to Busan than Fukuoka. (The author lives very near Osaka, though it's true that he doesn't seem to go there often).
It's true that Osaka is on a coast but it's not the coast which is mentioned by the book and blog I have quoted. Birds flying south for the winter from the Pale-legged LW breeding grounds on the continent to wintering grounds in southern China and south will logically end up on the western coast of Japan and its islands. But they would have to take a huge eastwards detour to end up in Osaka. But some birds may of course take a route over the sea of Japan and then the mountains of Japan to end up in Osaka.
If Pale-legged can be identified on appearance alone from your photo, then it's far above my competence. Unfortunately the two people I can think of who might be willing to comment on this are not active on Bird Forum at the moment.
HTH
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hi MacNara
Thanks for that, it's very much appreciated - I'm familiar with the blog you mention and it's a very good one.
I already have one Pale Legged at Nanko but was rather hoping to get a photo and this particular bird was different enough from the Sakhalin's that were also wizzing around there to get hopes up (here I used Brazil's Birds of Japan for the identification which, whatever its faults, is very, very good on warblers). As you mention most Sakhalin Leaf and Pale Legged Leaf Warblers do island hop but there is a small but significant stream which do detour through Osaka.
Thanks for that, it's very much appreciated - I'm familiar with the blog you mention and it's a very good one.
I already have one Pale Legged at Nanko but was rather hoping to get a photo and this particular bird was different enough from the Sakhalin's that were also wizzing around there to get hopes up (here I used Brazil's Birds of Japan for the identification which, whatever its faults, is very, very good on warblers). As you mention most Sakhalin Leaf and Pale Legged Leaf Warblers do island hop but there is a small but significant stream which do detour through Osaka.
James Eaton
Trent Valley Crew
as House Crow mentions, there is absolutely no plumage feature separating the two species, even in the hand only a few individuals are possible to identify due to wing measurements, depending on age/sex.
MacNara - it's well-studied that calls are different enough to separate using an in-bulit sonogram app for your phone to see the frequency of the call, unless you're very familiar with both, when identification by ear-only is possible. See: https://www.researchgate.net/profil...-legged-Leaf-Warbler-P-tenellipes-on-call.pdf
James
Thank you James.
My comment on the call of Pale-legged LW was based entirely on 'Birds of East Asia' which says it is 'probably indistinguishable from Sakhalin LW'. As I think was clear from my comments, I wasn't trying to make any claim on the basis of personal experience. So thanks again.
Living in Nara, east of Osaka, I have once had Sakhalin LW in my local spot in April - definite song ID - and have (poor) photos of the bird because it stayed high up (which I have been told is a feature - i.e. if there are high places to go, then it will go there).
I have seen also seen it in Hokkaido a couple of times.
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With many rare east asian species seen annually in western Europe (to use my region as an example) the value of an exact location in a country not too far from the main migration route is not very telling i would think. Most anything can turn up anywhere, especially during migration season.
Of course Hegura and Scilly Isles are generally better for rarer species, but that does not prohibit other spots from delivering the occasional rarity.
These 5 leaf warbler species in the pale legged and arctic warbler complexes happen to be a burden for every birder in the Japan area. Song and calls are usually helpful...luckily....luckily!
Cheers from the other side of the supercontinent,
Gerben
Of course Hegura and Scilly Isles are generally better for rarer species, but that does not prohibit other spots from delivering the occasional rarity.
These 5 leaf warbler species in the pale legged and arctic warbler complexes happen to be a burden for every birder in the Japan area. Song and calls are usually helpful...luckily....luckily!
Cheers from the other side of the supercontinent,
Gerben
Your comment is to me very strange and suggests a strong misunderstanding. Something that looks like the normal expected species in that location is likely to be that species.
The point is not that things cannot turn up in slightly (or sometimes majorly) off-the-route locations, but that if you want to ID them as something unusual, then you need a strong and definite ID feature to distinguish them.
So, the value of an exact location in a [location] not too far from the main migration route is, contrary to what you say, very telling unless you have some other strong feature which points to a different ID from what you would expect.
In my local spot in Nara, Japan, for example, I have been able to ID one Japanese LW and one Sakhalin LW because I carry around a voice recorder, and they called long enough for this to be of use. In the case of the Japanese LW, it could possibly have been ID'd on the basis of time (several weeks before Kamchatka LW) but it was good to have the call ID (I didn't do it only by myself, but asked an expert friend for confirmation). In the case of the Sakhalin LW, the behaviour was different from possible Kamchatka, but anyway the song was straightforward and recorded.
When asked about a difficult ID, in this case a leaf warbler with pale legs. The ID itself is not determined by how regular a species is in a certain area. That was all I meant to say...
Otherwise of course recording these leaf warblers is the way to go, until someone finds a common feature shared by all Pale-legged Leaf and not by Sakhalin.
Sorry if i come across a bit bluntly...it may be my English or just my dutch 'directness' at play here... or both
cheers,
Gerben
Otherwise of course recording these leaf warblers is the way to go, until someone finds a common feature shared by all Pale-legged Leaf and not by Sakhalin.
Sorry if i come across a bit bluntly...it may be my English or just my dutch 'directness' at play here... or both
cheers,
Gerben
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