Saturday, 5 December 2015

Great Grey Shrike aging

The Great Grey Shrike (varsler) is still going strong in Maridalen. It is a 1cy bird but depending on lighting conditions it is not always easy to see the small differences that allow one to see the difference between a young bird and an adult. The differences to look for are whether the lores are sold black, whether there is barring on the chest and whether the bill has an extensive pale base.
Yesterday I noticed that the Maridalen bird has different coloured lores on each side of the head which has probably added to some of the confusion regarding the aging of this particular bird.
1cy Great Grey Shrike (varsler).The faint barring on the breast is just visible
here we can see that the lores are nearly solid black on the right hand side of the birds head but are grey on the left hand side. The extensive bale base to the bill is visible on both sides though

in classic pose

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