I am not sure yet but I think the hen laying the dark spotted egg with good shape is the blue silver Cuckoo.Bummer! What do I do with her!
a lot thing you can do with any hen who lay dark eggs like that .breed dark eggs layer strain from her .
my friend you need a good Black copper marans rooster to work with .will help you to fix your problem very quick .
i ll try to hook you up with a DZ of BCM fertile eggs from some body soon .
chooks man