Can eggs bruise?

[TwoDogFarm]

This is probably a really weird question, but for the past week or so, some of our ducks have reached sexual maturity and started laying eggs. These are smaller than our older ducks, but I know they are duck eggs because of the waxy coating on the outside. Once I wash these eggs though, some of them have had dark splotches that appear to be beneath the egg shells. The eggs that are like this are usually ones I find dropped on the ground and some of the ducks did trample at least one of these eggs trying to get away from me when I was trying to get to it to pick it up. They didn't crack it, but it does show these marks that almost appear to be bruises. We haven't eaten these eggs yet, so I'm not sure what they look like on the inside yet.

Should I be concerned about my ducks? Could this be a sign of weakened shells? Or did they bruise the eggs by trampling them?

To be honest, we aren't sure which ducks are laying yet since we have some Pekins and Khaki Campbells that are around the same age. We know for sure due to coloring that we have at least two Khaki Campbell males, but aren't sure about the other two, and none of our Pekins have shown signs of being male or female yet. Please help.

 

[Amiga]

Hmmm, might they be stained? I have seen odd stains on eggs from time to time, but the eggs inside were fine.ç

 

[Nyssa03]

I have also had some odd stains on the eggs, they will usually wash off with a little scrub and hot water -- the eggs have always been fine.

 

[TwoDogFarm]

You all are right--they're stains. Our ducks like to keep laying their eggs in the mud. The spots occur where they have contact with the mud. I picked up one the other day that had gotten almost fully buried. When I dug it out, the whole egg was a grayish color. Silly ducks.