Dwarf muscovy

[Joyful_shay]

Does anyone have an idea why this duckling is so small and tiny?!He's the one in front in the first pic;its 12 weeks+ now,the others in the pic are its siblings and they're already 3times its size;in fact I sold some of them already,these are the remaining ones I'm keeping

 

[Duck mommy 2019]

could be female. what are you feeding?

 

[Joyful_shay]

Ok thanks;
I feed them GROWERS MASH and I allow them free range