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Photo © Keith Williams
Photo © Christine Boran

Rare Runt Egg Found

Christine Boran found this tiny Eastern Bluebird egg in a nest on April 4, 2019. Christine monitors the Woolwine House Bluebird Trail in Virginia, which is the same trail that produced a clutch of oddly shaped eggs last year.

Known as “runt eggs,” these yolkless eggs can occur if a sloughed piece of tissue finds itself in the oviduct. Once there, it stimulates the eggshell-forming process, and the “egg” is laid as a normal egg would be. Runt eggs are therefore not expected to hatch.

Cornell Lab of Ornithology

Cornell Lab of Ornithology