Halfsiders: Half-male, Half-female Birds

While technically not cryptids, "halfsiders" are quite a rarity and there have been few long-term studies of the birds and their behavior. The birds are examples of bilateral gynandromorphs, organisms in which a male and female embryo fuse during development. While similar fusion can occur between embryos of the same sex, the lack of contrasting sexual dimorphism makes identification far less likely.

From The Guardian:

“Our observations are among the most extensive of a bilateral gynandromorph bird in the wild”, Professor Peer and Mr Motz write in their paper.

The team report that the cardinal never appeared to pair up, nor did they ever hear it sing. Nor did the bird respond aggressively to recorded Northern cardinal songs that were played to it. Yet despite this bird’s seemingly solitary and silent life and bizarre appearance, Professor Peer and Mr Motz never observed its flock mates behaving aggressively towards it.

In halfsider birds, cells on each side of the fused embryo develop based on their chromosomal makeup, regardless of the hormonal milieu. In contrast, human embryos develop based upon the hormonal milieu that their cells are exposed to. For this reason, gynandromorphism doesn’t occur in humans or other mammals. In addition to birds, bilateral gynadromorphs sometimes pop up in a variety of spineless creatures (crustaceans, arachnids, and insects).

a reply to: theantediluvian

Wow!
Thanks for posting this. It is the first that I have ever heard of it.

Surprised the genus is not named Harvicus Twofacicus or similar....



Very cool! Never heard of this before now. Gotta love genetics!

a reply to: theantediluvian

cool, never heard of it in birds before - it does occur in humans though - and they sing!:

a reply to: theantediluvian

All Birds have the capability to shut off on half of their brain. It allows them to sleep with one brain half function. Therefore the bird can choose to be male or female, switch to one or the other depending on circumstance.

I thought you were talking about this lady

2nd