@AusHen Thank you for your amazing reply with pictures!
I think you’re exactly right; the rooster would need to have come from a speckled egg. The genes being passed on from father to daughter to her male offspringmakes sense. And my experiment seemed to confirm it: a non-speckled egg Roo produced a non-speckled EE daughter even though her mom laid a speckled egg. Thus the roo’s genes seem to play a major role. At least when it comes to the ‘overlay’ speckling genetics.
Makes those really gorgeous speckled Olive eggs that hatch out cockerels less disappointing! And if we know this, we can opt to hatch heavily speckled Marans eggs and select our breeding rooster from among the cockerels that come from those eggs.
Would it make sense to think that a speckled egg Roo and a hen that lays speckled eggs could result in Double Speckling sons? Can the speckling genes double up that way?