We recently got a baby pekin duck and a baby mallard, unsure of age but guessing under a week. The pekin seems to have poor balance compared to the mallard. He sits more on his elbows vs standing on his feet and is very wobbly. The mallard can lay and groom himself while the pekin tends to fall over. And to me it seems like he does circles at times when walking around. He is eating,drinking, and going to the bathroom fine and he can walk, just seems a little off balance. Is this normal for pekins? Do they take longer to grow into their legs? We are giving them a poultry probiotic with niacin in their water.