Friday, June 09, 2017

Gleaning Facebook: Cowbird

Here is another amazing photo from Gena Culbertson Flanigen. The cowbird fledgling on the left is being fed by the warbler "parent" on the right. Cowbirds are brood parasites. They make no nest of their own, but instead lay eggs in the nests of other species. The unsuspecting surrogate parents raise the aggressive cowbird chicks which often out-compete their foster siblings. In the case of the warblers, can you imagine any of the young warblers surviving in a nest with this big sister?
Cowbirds have been known to lay their eggs in the nests of over two hundred different species --- even hummingbirds and raptors according to Wikipedia! Can you picture a hummingbird successfully hatching and raising a cowbird chick?
This photo gives graphic evidence of the cowbird's success. On the other hand I am somewhat cheered to read that many species rid themselves of the invading egg by pushing it from the nest or burying it into the straw at the bottom of the nest or even deserting the nest altogether and allowing their own eggs to perish as well.
This warbler parent seems to have fully accepted the giant adoptive child.
Later Note: Gena has IDed the little warbler as a female Black-throated Green Warbler.




 

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