over preening mate

[HawaiianRing]

I have a pair of ringnecks alone in a cage. They appear to be bonded so I am hoping they will mate. I have added a nesting box for them and they both spend the nite sitting on the perch inside. During the day, a lot of time is spent with the male preening the female. The problem is, he has developed a habit of plucking out her feathers on her 2 cheeks. She now has bald spots on both sides of her head, exposing her ears. Why is he doing this and why is she letting him do this?

 

[Birdbabe]

Ringnecks can be aggressive and possessive, usually it's the females who are cranky and can actually kill the male's during breeding season, best to give up on babies for now, remove the nest box and separate them till hormones are over, best to be safe.