I have four hens and earlier this summer had three brown-egg layers and one Ameraucana laying bluish eggs.
Then I got ten ducklings, and three grew up to be girls. They have started laying. I sometimes have one little white egg on the ground that I know must come from a duck. One day I even found a little white egg in the lower nest that has a ramp. I continue to get brown chicken eggs. The rest is very confusing.
Sometimes I find a small bluish egg on the ground, and sometimes I find the same egg in the lower nest, which has a ramp. It's the color the hen laid all summer, but it's small and round like the new white duck egg. Then I have started having one big grey/beige egg each day. For a week I've had both the small bluish egg on the ground and also the grey/beige egg in a nest. I wondered if the grey/beige egg came from a duck, but I found one in the top nest which does not have a ramp. My runner ducks don't fly. This suggests it's an egg from the Ameraucana hen. But it does not have a hint of blue, just that strange grayish color, so I'm not sure it could be laid by my Ameraucana that laid bluish eggs all summer.
I don't have alternate nests, so I can't separate the hens from the ducks to find out who is laying what kind of eggs. But I'm so curious!!! I want to know who is laying what egg.