Have just bought a cockateil from local pet shop a week ago. He was the last one and looked a bit scruffy but i couldnt resist him but now im worried as he seems to be nibbling his feathers and the feathers round his neck and back look stubby. This is my first cockatiel so am a bit nieve about them athough i have been reading about them but have not found anything helpful.Would be gratefull for any advice.