The Great Grey Shrikes that nest in Wallonia have a characteristic white wing patch at the base of both the primaries and part of the secondaries. This is what was previously known as the «galliae » form of the species. But other birds appear in autumn and winter some of which have a wing patch that is restricted to the primary feathers only. The hypothesis that these birds have a more northerly origin has been tested using three sets of data: (1) the proportion of birds with a reduced wing patch in Belgium and in five other European countries; (2) the analyse of data from ringing; (3) the dates of arrival at wintering sites. The results suggest that the wintering birds have several provenances. We discuss the value of the reduced wing patch as an indicator of Nordic or Eastern provenance of birds.

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• Denis van der Elst
  Avenue Louis Van Gorp 9
  1150 Bruxelles
  Denis.vanderelst(at)gmail.com
  

  Arnaud Beckers
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  4000 Liège
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  Jérémy Simar
• 
  C. Pirson, A. Burnel, J. Fouarge & J-L. Dambiermont
• Nesting species in Wallonia in 2012
  Jean-Paul Jacob, André Burnel et les contributeurs-espèces