Egg Eating Birds
So you’ve had your ducks for some time, you’re getting eggs on a regular basis and it’s awesome… then you go out one morning and one of your ducks has a face full of yolk. Your duck has eaten her (or another ducks) egg! As disturbing as this may be to us we have to understand that this happens in the bird world from time to time. It can definitely be a one time thing. Some times ducks do this if the egg they’ve lain is cracked or broken during the laying. This would make sense in real world wild bird life, since as a bird this is just an invite to predators to your nest. In this case, there isn’t much to do about the situation except make sure the egg shells aren’t too thin and the nesting area has enough pine shavings or straw to keep the egg from hitting the floor too hard.
However, if your duck continues with this behavior then she may have a nutrition or behavioral issue.
Ruling out Nutrition.
If your duck needs more calcium she may be eating her eggs and shells to regain calcium. Be sure you’re offering oyster shell free choice to your ducks. If you have an all female flock and you aren’t feeding a layer feed, then consider making the switch. I don’t offer mixed gender flocks layer feed since males don’t need the extra calcium.
If your duck isn’t eating the shell, then it may be protein. My adults get a 15% crude protein feed, a level that has worked well for me. If your protein is lower, then you may want to consider switching to a higher protein feed.
Sometimes, nutritional deficiencies aren’t the culprit behind egg eating. In cases such as this, the duck may have discovered that inside the egg lies a tasty treat. Nutritional changes won’t change this behavior, so we need to make eggs less desirable to the duck.
Ceramic eggs or golf balls, usually used to train birds to lay in nesting boxes, can be left as decoys. The duck notices that sometimes trying to break an egg leaves her with nothing but a sore bill and the behavior is discouraged. This, paired with more frequent checking of nest boxes can break a ducks habit of egg eating.
I’ve never tried this method, so I can’t be certain of it’s effectiveness, but the logic seems sound (though it is more work than the fake egg method.) If you have access to eggs, but not ceramic eggs, you can poke small holes in the top and bottom of the eggs and blow out the yolk and whites. Rinse your egg shell, and air dry. You can then make one of your holes a little larger and add ½ tsp of mustard to your egg shell and put it in the nest box.
The egg eating duck will get something unexpected, and unpleasant. The behavior is discouraged through the duck learning that eggs aren’t tasty, though this will likely require multiple mustard eggs be made.