Gynandromorph Birds

3 02 2009

My friend Jim Meinhold (of Varied Thrush fame) sent me this great blog article and I thought I’d crib something from it just in case no-one had seen these amazing images yet.

They are of a gynandromorph bird (yes I had to look it up in wikipedia as well). Basically it’s an animal which displays both male and female characteristics and in rare occasions, as with this Cardinal, the animal can display bilateral gynandromorphism where one side shows male characteristics and the other female.

A quick search on the web for this rare phenomenon produced these pictures of a gynandromorph Evening Grosbeak skin. The Powdermill Website also has some cool pictures of Rose Breasted Grosbeak (more on their website  here)  and an Eastern Towhee showing similar characteristics (more here). I also found a couple of examples of cage birds.

Pretty interesting stuff and cool pictures. I just had to share!



3 responses

4 02 2009
steve t

Is this just the plumage? Or do they have mixed reproductive organs? Can they reproduce? And do they exhibit mixed male or female behaviour? I’d be interested to know…

4 02 2009

Hi Steve,

From what I understand they are sterile. I am assuming from the second part of your question that you are wondering if they sing or display etc. The simple answer is that I am not sure, although there is an interesting article from the New Scientist about recent studies that show that female singing is more prevalent than once thought

Of course most US birders can tell you that female Northern Cardinals certainly sing: and both Eastern Towhee and Rose-breasted Grosbeak females apparently sing as well. Another interesting line of study to explore. Thanks for the question Steve – there’s always new stuff to discover about birds that’s why I love them so much.


28 04 2009
Roy Neher

I have video and pics of a gynandromorph Northern Cardinal that I encountered a few years ago. I have posted a pic of it on the Birder’s World Magazine website.
A gynandromorph is not necessarily a hermaphrodite. that cannot be determined without it’s reproductive organs being analyzed.
A gynandromorph may have 2 testes with one of them producing female hormones or 2 ovaries with one of them producing male hormones.
Although likely to be sterile, some believe it is possible to reproduce if one of the reproductive systems is developed enough. As with one teste producing sperm.
Finding a mate that would tolerate it’s cross dressing ways might be very difficult, though. 🙂

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