Anybody that maintains and regularly checks eastern bluebird nest boxes in their yard can tell you that bluebird eggs are normally blue. However, from time to time, bluebirds do lay white eggs. In fact, biologists estimate that approximately 5 percent of all bluebird eggs are white.
Typically, if a female eastern bluebird lays white eggs, all of her eggs will be white.
However, on rare occasions, bluebird clutches will contain a combination of white and blue eggs. It is believed that the appearance of a white egg in a nest of blue eggs, or a blue egg showing up in a nest of white eggs occurs when a second female deposits an egg in a another female’s nest. This behavior is called dump nesting.
I have never seen a white bluebird egg. Have you?