Duck Egg Thieves, Not Laying, or Both?

OK, I'm new to ducks and need help solving a mystery. I have 4 runners and one I-forget-the-name-of. All were laying daily until a recent move 3 weeks ago.

The first day I found 3 eggs, one in a nest and the other two just haphazardly laying in the duck run. Nothing for the next few days until I decided to look in the pond--yes, I found one lone egg there, but that has been it! Since then, I have found no eggs anywhere!

At first I thought they weren't laying because of stress from the move, but after a week they seemed comfortable and happy in the new home. I thought it might be animals eating the eggs, but I never found a hint of an eggshell anywhere. The duck run is 5 ft high with 2 1/2 ft high chicken wire and mesh running across the lower portion of the fence. The pond area is actually fenced down to the very bottom of the pond with chain-link and it extends up from the water surface about 1 or 2 feet. The entire fenced area is about 20 x 18 ft, not including the pond.

The ducks are getting a laying feed and had been laying regularly. Oyster shell is freely available. Yesterday I decided they might just need some "encouragement." I placed 2 hard-boiled eggs in two different nests. This morning they were gone! There was no sign of a "break-in" from outside animals and I couldn't find a trace of eggshell anywhere! I thought, "That's it, they're eating the eggs themselves--or one of them is!" I started trying to find the tiniest of traces of eggshell or yolk anywhere in the pen or on their feathers or beaks. I couldn't find anything anywhere! (Maybe I just hadn't given them enough foraging area while trying to get them used to their new home?) Maybe they just didn't like the new home?

I walked over to my garden area (about 200 feet away) contemplating on how to find the culprit egg eater. Could just one or two ducks be eating every single egg every day with no trace? Were they all eating their own eggs suddenly? When I opened the garden gate, I took care to miss a shallow hole that had recently been dug just inside the gate. It was only four inches wide and a couple of inches deep, but I was wearing flip-flops and didn't want to trip. I took a closer look at the hole because a few months earlier I had seen a similar hole with a small rock in it, and the "rock" turned out to be about a 6" turtle. (Yes, I live near a creek.)

What the heck!!? There was some broken eggshell and a small bit of "hard-boiled yoke" laying in the shallow of that hole! No small turtle could drag an egg that far--could it? Plus, how could it get into the pen and find both nests? I think a skunk can climb a wire fence, but could it also carry an egg that far? Seriously, the duck area is over 200 feet from where I found the shallow hole and egg yolk with shell fragments. It would take a "pack" of turtles and skunks to eat all of the duck eggs wouldn't it?

I know for sure there are skunks and turtles around. (And raccoon, fox, etc.) But could any one be taking ALL of the eggs? I am really wanting to hear from anyone who has experience with turtles. I've heard they will actually kill and eat a duck by dragging it down into the water--but can this be true? I'm thinking there must be more than one problem here?

Can't wait to hear! Any turtle knowledge, skunk ideas? I've heard raccoon will climb fence, kill fowl and eat the eggs. My dog has heard and disturbed many skunk during the night (yes, I know it was skunk for sure!) but can just one thing be responsible for the complete loss and lack of eggs?