Saturday, August 15, 2015

Bobolink and Cedar Waxwing

I never thought that Bobolinks and Cedar Waxwings are very similar. Last Wednesday, I walked along the perimeter of the Dennison, Minnesota, water treatment pools. I was photographing a flock of a dozen Cedar Waxwings perched on the fence and flying down into the freshly mowed grass, presumably consuming abundant grasshoppers, a somewhat odd prey item for waxwings. I suddenly realized that two or three of the yellowish birds were not waxwings, but freshly molted, basic-plumaged Bobolinks. I made spishing sounds and one of the Bobolinks raised its body out of the tangled vines that lined the fence.
Because of its extensively black throat, this waxwing is a male. The red “wax” wing feather tips do not indicate the bird’s sex or age. Bobolinks are more difficult. After their juvenal plumage, they molt into a pre-basic plumage. They then undergo another molt into their Basic or Winter plumage. Adults undergo a complete molt into the same plumage. The sexes are similarly patterned. I guess that the birds in this post are first-year males, recently molted into their pre-basic plumage. Such birds are darker breasted than adults and males are brighter yellow than females. Older birds should show a few yellow-tipped, black feathers on their chins breasts (Martin and Gavin 1995)

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