Missing duck egg?

[brooder]

Hi there,
I've been consulting the BYC forums for all kinds of information today, as my duck has recently become a first time mom! However, only one out of two eggs hatched yesterday. I checked the nest this morning and fount the shriveled up remnants of where my duckling hatched, but found no sign of the second egg. All I could find was a wet spot in the corner with clumps of damp down. I found no fetus, but I know for a fact that the egg was there just the other day! What does this mean?! Could the mom have eaten it? Could something else have gotten to it? The nesting box is an eglu attached to an extension, there were no signs of entry and the mother and babies were unharmed. Sorry if I'm in the wrong forum.
Any potential solutions to this mystery are appreciated.

 

[Chick-N-Fun]

This has happened to me with my last batch of eggs. Your mama probably destroyed it and ate it. Their instincts know if an egg is a dud or quitter and they take care of it so that the rest of the eggs aren’t compromised. I was shocked when I couldn’t find the egg that was there earlier.....I searched high and low and soon sound a piece of egg shell. I was so upset, but then figured that my broody knew what she was doing. So sorry....

 

[chickens really]

Sometimes first time Mommas will kill the first to hatch because she doesn't fully understand and her hormones might not be in Momma mode yet. Or she knew something was wrong with it so she disposed of the evidence.
Congrats on the Duckling..My Hen killed a disabled Duckling that was 2 days old. I always think they know more than we do when it comes to hatching and raising Babies..