Hello. I have a concerning question as I am a rookie to duck owning. I have a 2 week old Cayuga whom is now, "balding" along it's backside from it's butt region, stretching upward to it's wings. It appears like a Mohawk. He also is bunked with 4 mallards and 1 Cayuga. They all are 2 weeks old. He is also, the smallest duck of the bunch. I am asking to know, if this is abnormal and or normal? I thought he may be a runt. None of the other ducks have this occurring. Thank-you.