Bilateral Gynandromorph Cardinal

Photographs, text, and copyright by Larry P. Ammann

One morning in January, I noticed a female cardinal at our feeder, but when I looked closer, I saw that it had the bright red crest of a male! At first, I only saw its right side, but then it hopped to the other side of the feeder so I could see its left side, and now it had all the markings of a male! I went to get my camera but was only able to get one shot. Fortunately, it stayed in the neighborhood and I have been able to get many more shots of this beautiful, but confusing, bird. After making inquiries via the web, I've learned that this is an extremely rare bilateral gynandromorph cardinal. What that means is that a genetic mistake occurred during the first division of the fertilized ovum that caused one half of the bird to be male and the other half to be female. So the male side has a testis and the female side has an ovary, in addition to the feather coloration. Although gynandromorphism is known to occur in other birds, it is particularly striking in cardinals due to their strong sexual dimorphism. I have included a few shots of normal cardinals here for comparison.