We had gotten some chicks from tractor supply, 3 of them where the same age and 2 of them are the same breed. They are we believe black astralorps (not sure if thats correct spelling). One astralorp has all feather except on "her" head and has quite the tail. The other one still doesnt have neck feathers or all its wing feathers, its tail is just a tiny stub. Is this normal? Or is there possibly something wrong with my chick. We have had them for about 6-7 weeks. Not 100% sure their actual age (new to this chicken stuff). Can anyone help?