Phylloscopus from Tainan, Taiwan, April 2020 (1 Viewer)

SteveMM said:

Presumably a Two-barred Warbler, I find the colour scheme of this one peculiar (although it may be being affected by surrounding foliage). I’ve only seen autumn Two-barreds before, and they’ve tended to appear a lot more contrasty. The wingbar also looks short.

There were some vocalisations: a trisyllabic 'chir-wee-wee' call note and an abrupt, almost Hartert’s-like ‘pit-su-i’ song note. The call does fit Two-barred, but the plumage still seems odd. Will fresh spring Two-barred look like this?

Click to expand...

andyadcock said:

How useful is leg colour?

Birds of Taiwan notes 'dark greyish' for Greenish and 'blackish brown' for Tw-barred, I'd say the legs on the OP appear greyish?

Click to expand...

HouseCrow said:

Hi
I'm a beginner at (East Asian) leaf warblers, hoping to learn and still struggling with the relatively few Japanese options, so
'presumably Two-barred' because of the calls? This could be one of the arctic complex for me (i'm a beginner remember)


Could you maybe elaborate a bit more?

thanks!
Gerben

Click to expand...

Grahame Walbridge said:

Leg colour is variable across the complex Andy, and that's before factoring in lighting/photographic effects. Ticehurst describes the leg colour of plumbeitarsus as 'pale plumbeous brown or lead colour' hence the latin name, which may be good indicator though not diagnostic. As to the OP, I am struggling to make out precise leg colour from the images.

For comparisons of vocalisations see https://soundapproach.co.uk/song-and-call-identification-of-the-first-green-warbler-for-the-netherlands/

BTW, just to be clear, I am not saying its a certain Two-barred given the apparent anomalies.

Grahame

Click to expand...

SteveMM said:

Thanks for the various links, Grahame; I'll trawl through them.

The May bird from Beidaihe does look similar in many respects, including the presence of yellows in the face and below. The attached may show leg colour a bit clearer, but I find leg colour quite variable in Phylloscs and am not sure how useful a correct determination of colour would be. They're certainly very dark, anyway.

Steve

Click to expand...

HouseCrow said:

thanks for clarifying that Steve, and to all elaborating others for the extra info.
Am I wrong in thinking that
-Primary projection is not visible enough to help ID
-Leg-colour seems to only rule out the light-coloured leg-species
-Song and call don't fit Arctic-complex (i understand) but don't exclude any other?
-The wingformula is not clear enough here for eliminating species? (emarginations etc)

sidequestion: is bird-ID at ebird properly verified (I think so, but I couldn't find info on it) (answered: https://ebird.org/australia/news/how-does-the-ebird-review-and-data-quality-process-work)

cheers and good luck with this and other tough quests

gerben

Click to expand...

andyadcock said:

My unqualified leaning would be toward Greenish.

Click to expand...

Grahame Walbridge said:

To answer a couple of your queries Gerben, its true the images are not very helpful when it comes to assessing wing formula and pp which, is no fault of Steve's I hasten to add; p1 is largely hidden beneath the wing (though clearly >pc), emarginations difficult to resolve though appears slight to p6 (image 3), while p2 falls well short of wing point (image 4) which indicates Greenish complex. Like members of the Arctic complex, differences between (Greenish) taxa are minimal and of little use when it comes to ID.

Grahame

Click to expand...

johnallcock said:

One question I would have is whether the vocalisations you have recorded are calls or introductory notes to a song. To my ear, the recording seems to include various different vocalisations, and it may not be appropriate to compare all of these to the typical call.

I sometimes encounter Two-barred singing in Hong Kong in April, shortly before they leave for the breeding grounds. The songs are not as long or complex as those published or available online from within the breeding grounds. I tend to assume that these are plumbeitarsus 'warming up' in preparation for the breeding season (it is generally assumed that most birds in HK are plumbeitarsus)

If these are songs, one taxon that may need to be considered is obscuratus. The sound approach page linked earlier by Grahame includes sonograms of obscuratus which show that the song is simpler than plumbeitarsus, and also that the elements of the song have a 'W' structure similar to your description for your bird and for Green.

I suspect that your bird is plumbeitarsus, but I'm not entirely sure. I find this complex very confusing. Most of the existing literature focuses on the differences between the most distinct taxa (viridanus and plumbeitarsus), which I think lead to obscuratus (and possibly trochiloides) being overlooked so that their distribution and movements are currently not properly known.

Click to expand...

SteveMM said:

Thanks, John. You make vaild points as always.

Out of interest, do you see many spring Two-barreds in Hong Kong that lack the upper wingbar? As I said in #1, I have only seen autumn individuals before, and these have always sported two clear wingbars.

Steve

Click to expand...

johnallcock said:

Unfortunately I also tend not to see so many this late in the spring. I know that the wing bars in late winter are often quite worn and the upper wing bar is not always visible. I don't think these are replaced during the pre-breeding body moult but I'm not entirely sure (Grahame may have a better idea).

Click to expand...