Ok, I know I have 2 runners and 2 pekins but I have no idea what the grey duck is. Does anyone have an idea? Also, What sex are they all. The smaller runner and the smaller pekin have a deep quack and dont move their beak when they quack the larger quack and move their beak. Dont know if that matters or not. Also the grey duck has the deeper quack without beak movement. I want eggs and some fertile eggs so I dont know who to keep or eat. Any help would be awesome.