It is true. The evidence suggests that thunbergi migrates east into Central
Asia, whilst macronyx migrates south along the Pacific rim into southeast Asia.
Regards,
Simon.
> From:
> To: ; ;
> ;
> Date: Sat, 20 Feb 2010 15:17:47 +1100
> CC: ; ;
> Subject: [Birding-Aus] RE: Western Yellow or Green-headed Wagtails in WA
>
> Would very much like to see the photos Mike and John.
>
> How have you excluded macronyx in this instance in favour of thunbergi, did
> the bird show any signs of a nexklace.
> One possibility for us not getting thunbergi is that its expansion into the
> east is very recent, post glaciation, and like other taxa such as eastern
> populations of Ringed Plover their preference may be to continue migrating
> to regions further west.
>
> Cheers Jeff.
>
>
>
>
> -----Original Message-----
> From: Mike Carter
> Sent: Saturday, 20 February 2010 2:37 PM
> To: BIRDING-AUS; John Darnell; Frank O'Connor
> Cc: Jeff Davies; Sean Dooley; Bill Ramsay; Danny Rogers; Rohan Clarke;
> Adrian Boyle; Tony Palliser
> Subject: Western Yellow or Green-headed Wagtails in WA
>
> John Darnell has sent me some poor photos of some Yellow Wagtails seen at
> Cranbrook in SW WA (north of Albany). Unusually far south for such birds. If
>
> I read the camera data correctly they were taken on 21 January 2010. It
> seems that several birds were present, some advancing into breeding plumage.
>
> I'm told that they were initially claimed as Grey Wagtails but this was
> corrected to Yellow Wagtail. They may still be there - are they Frank?. Now
> the claim is that they are Eastern Yellow Wagtails as one might reasonably
> expect. John agrees that some probably are that species but it is clear that
>
> some are not. Some have no white supercilium and John suspects that they are
>
> what today we would call Western Yellow Wagtails of the race thunbergi. He
> uses the name 'plexa' which was the name given to the far eastern forms of
> that taxon now subsumed into thunbergi. Western Yellow Wagtail is not yet on
>
> the Australian list but perhaps only because of the difficulty/impossibility
>
> of telling thunbergi apart from macronyx. Although intuitively wrong,
> macronyx is considered a subspecies of Green-headed Wagtail (taivana) which
> is on the Australian list because adults of the nominate race are annual but
>
> rare in NW WA and occasional in the NT. Occasionally those areas too get
> birds which look like these. Macronyx has been claimed (with and without
> photographs from both Christmas and Cocos Islands. These are very colourful
> birds with blue heads. It seems odd to me that we should get the Mongolian
> macronyx and Manchurian taivana rather than the Siberian thunbergi. Our
> usual Eastern Yellow Wagtails tschutschensis breed in the intervening region
>
> and further east. This situation of the more southerly breeding populations
> coming further south is contrary to the strategy adopted by other migrants.
> More northern birds usually leap-frog there southern counterparts.
> Anyway, you Western Australians, get behind John and the WA Museum and not
> call thunbergi/macronyx birds Eastern Yellow Wagtails. They are either
> Western Yellow Wagtails or Green-headed Wagtails even though you may not
> know which!
>
> Mike Carter
> 30 Canadian Bay Road
> Mount Eliza VIC 3930
> Tel (03) 9787 7136
>
> ===============================
> www.birding-aus.org
> birding-aus.blogspot.com
>
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