what kind of chickens do you have? Guinea eggs are usually about half the size of a large egg. These are almost the same, maybe even slightly bigger, that's why I lean duck. Most ducks are pretty good fliers to a degree. I guess it would depend on breed again.
They look more like a duck egg. My ducks first eggs were about the size of chicken eggs, but had that look to them. Guinea eggs have a pretty distinctive shape to them that I'm not really seeing here, and more around the size of bantie eggs. Try cracking them, Guinea eggs are like trying to...