Potential Eastern Yellow Wagtail in Cornwall?

[jamesg]

I feel bad about completely pirating a birdforum thread, but it would be good to get some discussion on here about this bird (http://www.birdforum.net/showthread.php?t=107345).

One of the observers describes a “rasping” call, which certainly sets alarm bells ringing. For reference, I’ve attached a recording of Eastern Yellow Wagtails I made last summer in Chukotka, Russia (includes alarm and standard flight calls, sorry for the poor quality).

If the Cornwall bird is a genuine match, I’d say it is potentially the most interesting bird in the UK at the moment. I'm not sure whether the status of Eastern Yellow Wagtial (M. (f.) tschutschensis) is under review with the BOU, but it certainly should be. The AOU treat it as a full species, and it could also qualify under the BOURC TSC's criteria. I know there are a number of previous claims, but I’m not sure how many are well documented with sound recordings etc..

Several phylogenies have been published, with universal agreement that the western and eastern clades of Yellow Wagtail are highly divergent (probably not even each other's closest relatives, with citreola somewhere in the middle). Differentiation by plumage/morphology needs further study, but juvenile Easterns are highly distinctive, lacking yellow tones and being more heavily marked on the head and wings. Adults also differ in that they lack any clear sexual dimorphism, at least in the two most widespread forms, nominate tschutschensis and macronyx. By far the biggest differences, however, are in vocalisations. All eastern forms have highly distinctive calls – check out the recording – they are even more distinctive than citreola. Males of tschutschensis also have a more complex song than western forms of flava.

The taxonomic situation is muddled by a lack of data from the contact zone between eastern and western clades, which lies somewhere in central Russia (between nominante tshutschenis and thunbergi). It would be great to hear from anyone who has experience in this area…

Anyway, the Cornwall bird - is it an Eastern Yellow Wagtail? Certainly the grey plumage tones and large bill are good pointers, but plumage and morphological differences are variable and poorly understood (particularly in winter), and there may be complete overlap with western forms. It would be great if someone could get some good quality recordings of it – the calls may well be diagnostic. No doubt the biggest issue will be eliminating the south-eastern forms of “Western” Yellow Wag, which also have raspy calls, more similar to citreola.

Hopefully if this bird stays around it will galvanize some more interest in this 'form'…

[jamesg]

Just to add a bit more detail on tschutschensis vocalisations - I've attached a sonogram that I've pulled from my recording. I've edited the timing a bit to get three good calls onto the image.

The first and third calls shown are typical flight calls, often described as "pseeu" or "tzrep". These are the drawn out, red-throated pipit-like calls that can be heard on the recording.

The middle call on the sonogram shows one of the short, clipped alarm calls - I'd describe it as a "te-chip" sound. This call interests me the most - I heard it very frequently from the breeding birds I encountered in Russia, and it is unlike anything I've heard from other forms of Yellow Wagtail.

I've been comparing my sonogram to those shown in Alstrom & Mild's "Pipits and Wagtails" for various other forms (I have used the same scale on my sonogram). I can't see anything similar to the clipped "te-chip" call on any of those sonograms. I wonder whether this call could be diagnostic? I also wonder whether it is ever given during non-breeding periods?

[Harry Hussey]

Hi James,
This bird was found by the legendary Graham Gordon, who is currently living in Cornwall: he didn't pin it down on the deck for a few days after first having it, but had already suspected that it sounded reminiscent of the more eastern races, these suspicions being fuelled further when he did see it well, due to the grey upperparts etc.
I know very little else about eastern Yellow Wagtails beyond that which you have mentioned above, but I seem to recall an article in Birdwatch suggesting that claw length may prove to be useful, with eastern birds having a longer hind claw than most (all?) western taxa. Perhaps the bird could be trapped (a blood sample could also be taken if this were the case), or, failing that, if there are any exceptionally good sharp pics where the whole foot is visible, the length could at least be estimated by comparison with nearby twigs etc?
Harry

[Chris Benesh]

For reference, I’ve attached a recording of Eastern Yellow Wagtails I made last summer in Chukotka, Russia (includes alarm and standard flight calls, sorry for the poor quality).

Hi jamesg,

Thanks for contributing the sound file and sonogram of the Eastern Yellow Wagtail and for generating the discussion. Hopefully there will be more contributions to this thread, as I am interested to see how this pans out too. The only form of Yellow Wagtail that I am somewhat familiar with is tschutschensis (which I only see on its breeding grounds in Alaska) and a bit of exposure to breeding iberiae. The gain on your recording was quite low, so I posted a 'cleaned up' version that may be easier for folks to hear (hope that is okay).

Chris

[AndyB]

Thanks for starting the thread James. I got to see my first tschutschensis last September in southern California. The following photos show how gray and white it was. Seems to also show a pretty good supercilium, white lower eyering and well-marked breast. It called frequently - unfortunately it's been a while since I've heard western Yellow Wags but seemed a dead ringer for your mp3 (compared to western yellow wags I listened to on the web).

Doesn't seem to be many photos on the web of tschutschensis so thought I'd post a few links.

My terrible photos:
http://www.surfbirds.com/blog/albums/labirding/
Chris Taylor managed a good shot here:
http://www.kiwifoto.com/galleries/birds/eastern_yellow_wagtail/
I also attach a photo that was taken by Dave Furseth to this post.

Another 1st winter from CA
http://fog.ccsf.cc.ca.us/~jmorlan/yewa170905.htm

Adults
http://www.bobsteelephoto.com/Species/ywag.html
showing hindclaw
http://www.flickr.com/search/?q=yellow%20wagtail&w=27431055%40N00

attached photo by Dave Furseth posted on LACoBirds yahoo group

[jamesg]

Thanks for the responses folks - I see in addition to Keith Vinicombe's article in Birdwatch (thanks Harry), there was also this one in British Birds (http://www.eurobirding.com/birdingmagazines/artinfo.php?id=9172). Unfortunately I can't get my hands on either article at the moment. Does anyone know if any other ID features are touted?

The hindclaw could be very useful - it certainly seems pretty long in the pic Andy linked. I had a trawl through my photos from Chukotka, and found the attached image (a juvenile already completing post-juv body moult) showing some impressive hindclaws.

Alstrom & Mild's account in Pipits and Wagtails is pretty disparaging of hindclaw length as a feature for separating Eastern and Western ssp, suggesting that there is too much variation within forms for it to be any use. However, it's not clear how many individuals (and of what forms) they measured...

It looks like a fair few people have now listened to the sound files - so has anyone out there ever heard similar alarm calls coming from western-clade Yellow Wagtails?

[Alex Lees]

The taxonomic situation is muddled by a lack of data from the contact zone between eastern and western clades, which lies somewhere in central Russia (between nominante tshutschenis and thunbergi). It would be great to hear from anyone who has experience in this area…

I've attached a map from the Pavlova et al. (2003) (http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1642%2F0004-8038(2003)120%5B0744%3APPIMFA%5D2.0.CO%3B2) phylogeny; showing the collecting localities and hence the distribution of M. flava. They consider that the species should be split 3-ways (on the basis of reciprocal monophyly of mtDNA haplotypes) into M. flava (Western birds), M. tshutschenis (NE Asia) and M. taivana (SE Asia).

Alex

[garry1366]

Thanks for the responses folks - I see in addition to Keith Vinicombe's article in Birdwatch (thanks Harry), there was also this one in British Birds (http://www.eurobirding.com/birdingmagazines/artinfo.php?id=9172). Unfortunately I can't get my hands on either article at the moment. Does anyone know if any other ID features are touted?

The hindclaw could be very useful - it certainly seems pretty long in the pic Andy linked. I had a trawl through my photos from Chukotka, and found the attached image (a juvenile already completing post-juv body moult) showing some impressive hindclaws.

Alstrom & Mild's account in Pipits and Wagtails is pretty disparaging of hindclaw length as a feature for separating Eastern and Western ssp, suggesting that there is too much variation within forms for it to be any use. However, it's not clear how many individuals (and of what forms) they measured...

It looks like a fair few people have now listened to the sound files - so has anyone out there ever heard similar alarm calls coming from western-clade Yellow Wagtails?

James,
I've never heard these alarm calls but I have heard presumed Iberian birds in Morocco giving very Citrine like rasping calls.

G

[forktail]

Thanks for the responses folks - I see in addition to Keith Vinicombe's article in Birdwatch (thanks Harry), there was also this one in British Birds (http://www.eurobirding.com/birdingmagazines/artinfo.php?id=9172). Unfortunately I can't get my hands on either article at the moment. Does anyone know if any other ID features are touted?


Hi James

the general gist of the letter is that although some autumn 'grey-and-white' birds may be of 'eastern' origin, it could also be that some beema and some (possibly one-third to one-half) of feldegg could also be similarly 'grey-and-white' and potentially some flava and thunbergi as well.

There is a BBRC response which says that tschutschensis / taivana may potentially differ from these grey-and-white birds of a more westerly origin, in head pattern (as tschutschensis and taivana differ in this way themsleves) but it's not fully understood yet.

They also note that 'grey-and-white' flava/thunbergi are not actually monochrome but usually exhibit some brown in the mantle while feldegg and beema are genuinely monochrome birds and the figures given above may relate to 'greyish and whitish' birds rather than true monochrome individuals which should lack brown and buff tones as well as yellow and green.

It then goes on to confuse things a little by saying that although a proportion of first-winter far-eastern birds are monochrome, NOT all are.

rgds
F.

[Alex Lees]

It then goes on to confuse things a little by saying that although a proportion of first-winter far-eastern birds are monochrome, NOT all are.


indeed.... see these Norwegian candidates (http://www.fugler.no/id/200311_flava.htm)

[macrourus]

I dot not would express a firm opinion on this bird, as too variable taxa group and I prefere to study them in the field,

but what I could say is that feldegg would show a much longer, stronger bill, often upcurved a bit... as well as cinereocapilla and iberiae (to a lesser extent though) would show.

I found Eastern YW to have a quite small, short, compact bill, a quite small and round looking head all in alla a more compact and crunchy roundish bird....

I do not know if it is of any use but... :-)

Ciao

Andrea Corso
________
Lbo Dispensary.Com (http://www.dispensaries.org/)

[Alex Lees]

DNA says yes (http://devonbirdnews.blogspot.com/2011/03/colyford-yellow-wagtail-uk-first.html) on the Colyton bird...... One wonders then how many wintering 'yellows' could be Eastern. A search of Birdguides reveals no Jan records, will have to dig up any notes on the yellow that wintered on my Lincs patch in 1992-1993 (http://www.lincsbirdclub.co.uk/Articles/Birds_Grantham/birds_of_grantham_8.htm)...

[LeeEvans]

Interesting link Alex. This is certainly NOT the first record for Britain but perhaps the first PROVEN record of 'Eastern Yellow Wagtail'. I have at least 36 records on file of 'presumed' Eastern Yellow Wagtails, all matching this bird in appearance and sharing the distinctive (but nothing like diagnostic) rasping call of the eastern clade - both Scilly and Shetland recording a number of candidates. I do not believe that this is a particularly rare bird in Britain, perhaps averaging at least 1-3 records per annum. The main problem is identification and separation from a bewildering array of autumn first-winter flavas, some 'eastern' Grey-headed-types often being virtually inseparable and occasionally calling similarly.

Having just returned from Morocco, I must say that the calls of Iberian Wagtail are equally as distinct as the contact sounds made by the eastern clade - Egyptian Yellow Wagtail being even more distinct and much more worthy of species status

[Alex Lees]

Interesting link Alex. This is certainly NOT the first record for Britain but perhaps the first PROVEN record of 'Eastern Yellow Wagtail'. I have at least 36 records on file of 'presumed' Eastern Yellow Wagtails, all matching this bird in appearance and sharing the distinctive (but nothing like diagnostic) rasping call of the eastern clade - both Scilly and Shetland recording a number of candidates. I do not believe that this is a particularly rare bird in Britain, perhaps averaging at least 1-3 records per annum. The main problem is identification and separation from a bewildering array of autumn first-winter flavas, some 'eastern' Grey-headed-types often being virtually inseparable and occasionally calling similarly.

Having just returned from Morocco, I must say that the calls of Iberian Wagtail are equally as distinct as the contact sounds made by the eastern clade - Egyptian Yellow Wagtail being even more distinct and much more worthy of species status

Hey Lee

I'm well aware of both the history of autumn reports and the intractability of their field identification.... JG and myself have looked at skins... But, I wasn't quite so acutely aware of YW's rarity in winter - biased by the fact that I has seen one - I had presumed there were near-annual reports (?). Given say the predominance of 'eastern' Lesser Whitethroats as wintering birds then perhaps the same is likely to be true of YWs.

The genetic data certainly don't suggest that pygmae is a 'better species' than the well-documented basal east-west split. However Anders Ödeen's PhD thesis (attached) does indicate that pygmae has higher haplotype diversity and more song elements than other subsp., perhaps to be expected given the allopatry of this population? Either way this example illustrates several neat points:

1) 'Scatter-gun' evaluation of genetic variability of Holarctic taxa may produce both surprises and disappointments for field birders....
2) 'Test-tube' diagnosis of suspected extralimital records of cryptically-similar taxa is probably the only safe way of knowing 'for sure' in many cases....
3) Species limits are set to change in many cases, especially so in the east...

Alex

[Martin Garner]

In case you hadn't seen it, a reasonable claim of eastern flava from Helgoland, Germany last month (May 2011). Unsurprisingly if they winter (e.g. the Colyford bird) they will also presumably occur occasionally on spring passage. Interesting too the plumage as per autumn/winter thus a 2nd cal bird? Any other spring claims?

Photo etc:

www.birdingfrontiers.com

Martin