idk how to tell a fertile egg from a nonfertile one but i think theres a way without breaking it...
i hope its Miracle's
do guinea roosters crow loudly? do they crow at all? im guessing they dont because that would explain why you have so many... or maybe that's just because they don't fight at all or just not often.
well it could very well be miracles because if he/she is mixed with a chicken it gets the color from the guinea but with chickens gets the largerness. if that makes sense.