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Monday, January 10, 2011

A catch up item….

I just want to throw this item in here before I forget completely….just before Christmas I noticed a Varied Thrush on one of my feeders…the bird has a ‘crossed’ bill.

Varied Thrush with cross bill - #5189

If you look closely at the tip of the bill you can see that the top mandible curls downwards and twists to the side while the lower is longer than normal and also twists slightly.  In the mid 1990’s birders in Alaska started noticing birds, primarily Black Cap Chickadees, with curved and or, abnormally long bills.  Shortly thereafter the University of Alaska started a study.  To date something like 35 species, including Varied Thrush, have been observed with this deformity.  To date the cause of it is still unknown but it is estimated that as many as 18% of the birds in Alaska are affected.  Anyone seeing such a bird is asked to report it to the U.of A., which I have done.  I first saw him on Dec. 22’nd and he continues to come to my feeder regularly – I think it is easier for him to pick up food there, than on the ground.

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