Black copper maran has bald patch on her neck

[kkcleek]

We have five hens in a backyard coop. They free range during the day. For the past few months only the BCM had a bald streak on the right side of her neck. I noticed this morning that some of the new feather tips on the breast have white tips. She is eating well, laying well and otherwise seems happy. Should I be concerned? What might be causing this? Thank you for your replies!