Egg inside an egg??

[xmarcheeba]

Found this this morning. The egg on the inside is an egg from one of my Caramel Queens. Is this something that happens when they molt? I've got two CQ and one is molting. ...otherwise I have no idea what happened here.

 

[ChickenCanoe]

Take good pictures. That is an extremely rare occurrence. So rare that there's no data that explains why. For some reason the fully formed egg backs up in the reproductive tract through the uterus, isthmus and magnum; then joins up with a newly released ovum. Then it moves downstream again and gets new albumen and shell.
I saw a picture once with a green egg inside a brown egg. Probably the blue pigment was already spent and only the brown was applied to the second shell.

I doubt it has anything to do with molt. During molt, there are usually no eggs.

 

[donrae]

Agree it's not due to molt, more likely due to the high production nature of your birds. They're more prone to reproductive irregularities like this as their bodies try to keep up the production rate they're bred for.