Bizarre duck egg

[Ole McFarland]

This morning I found a duck egg from one of my 2 year old rouen ducks right next to the water pool. They always lay in their box so it's placement alone was bizarre to us. The egg has a plastic bag looking skin around it. I pulled some off to investigate but since I've never seen this before, I left it as is for the most part. Does any one know what this is or why it happened? All my duck eggs are presumed fertile.

 

[AnconaDuckFarm]

It was probably just a one time mistake. Maybe a lack of calcium or vitamins. Did it freeze at all?

 

[Ole McFarland]

No freezes here in Central Florida yet. Any idea on what the sac or skin around the egg shell is? The shell is hard, the stuff around it is a lot like the lining that is around the inside of an egg. Thoughts?