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bilateral gynandromorph

Two For One

2-15-19 cardinals _U1A8442Thanks to warmer temperatures and a vast increase in the number of bird feeders, Northern Cardinals have expanded their range northward as far as Canada over the past century. Males get far more attention than females, due to their year-round brilliant red plumage. However, the female Cardinal is equally striking with her more subtle tan plumage highlighted with touches of red. Believe it or not, it is possible, albeit very rare, to find both of these plumages on one bird.

Recently an interesting phenomenon known as a bilateral gynandromorph was recorded in Pennsylvania — a cardinal whose body is half male, half female. (For a detailed explanation and video, go to Not just the plumage, but the anatomy of this bird is half male, half female. The way in which this gender division exists has a unique effect. According to National Geographic, “Most gynandromorph individuals are infertile, but this one may actually be fertile as the left side is female, and only the left ovary in birds in functional.”

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