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Interesting Great Grey Shrike, SW England (1 Viewer)

mark dowie

Well-known member
United Kingdom
All

I would welcome any thoughts on a GGS recently present in SW England

A striking bird at first sight (confirmed by others when drawn to their attention), but failing to draw any real observer comment and presumably regarded as ‘just a great grey shrike’ due to typically distant views &/or lack of close scrutiny

I was able to obtain reasonably close views over a prolonged period of observation, and have attached a number of photos which illustrate (albeit poorly) the following features noted at the time

  1. Striking appearance notably due to pale appearance and significant amount of visible white on upperparts
  2. Pale area just above the lores
  3. Little/no white supercilium stripe above balck mask
  4. Significant white scapular crescent
  5. Upperwing white patch at base of primaries continuing without break onto base of secondaries (but sec’y patch not quite as wide)
  6. Photos reveal no bleeding of white along the edges of the secondaries i.e. spiking towards trailing edge of wing
  7. Extremely broad white patch on trailing edge to closed wing formed by broad white border to lower tertials and inner secondaries
  8. Significant white in tail including seemingly white outer tail feather T6
  9. Noticeably pale(r) rump compared with mantle / back
  10. Slight white edging to primary tips
  11. Ash grey underparts with no barring
From early but inconclusive research, it would seem to most resemble L excubitor excubitor white-type variant (per Garner Challenge Series - Winter i.e. white on base of both primaries and secondaries). Garner states that this and melanopterus variant (no white in secondaries) are the two forms that most UK GGSs fit. The photos do not seem to provide sufficient ‘fit’ to the full suite of features required for a classic homeyeri although there is a close resemblance to a shrike illustrated on the Birding Frontiers website
http://birdingfrontiers.com/2010/11/05/homeyeri-great-grey-shrike/

And I can find few examples of birds revealing such a marked amount of white on the trailing edge to the wing?

Recent publications on GGS taxonomy seem to promote this view of two main variants within the nominate subspecies (and this is supported by close scrutiny of photos taken in the UK with birds showing both limited and extended wing patches) although the position is complicated by significant variation in appearance within forms and the possibility of intergrades or even hybrids in transitional zones across Europe, across to the Ukraine and Western Siberia

I certainly don’t think that this is a homeyeri but the anomalies in plumage stated above (in addition to the extended white patch into the secondaries) would seem worthy of discussion

Any thoughts would be appreciated


M
 

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Hi Tom

Thanks for this - really helpful. I hadn't seen the other thread so looking forward to doing some more reading!

So in your opinion this puts the ID firmly in the L excubitor excubitor camp using Martin Garner's latest classification, i.e. what would previously have been known as galliae? I note that references often cite that galliae can closely resemble homeyeri, all of which makes perfect sense here

Best wishes

Mark
 
Tom

Great stuff - thanks

Sexed as Male because of the uniform wing bar without step between base of primaries and base of secondaries?

Cheers

Mark
 
So in your opinion this puts the ID firmly in the L excubitor excubitor camp using Martin Garner's latest classification, i.e. what would previously have been known as galliae? I note that references often cite that galliae can closely resemble homeyeri, all of which makes perfect sense here

yes, but galliae is no more valid ssp for a long time and I fully agree to invalidate homeyeri as well

If they're part of clinal variation, you can still have distinctive characters at one end of the cline, even if (because of a full set of intermediates along the cline) you can't make a valid subspecies out of the difference :t:
 
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