Cherry finch feathers missing?

[finchbob]

One of my female cherry finches has lost a bunch of feathers, some to her side near her chest, and now some on her back. She looks fine, other than that it looks like someone plucked loads of her feathers out. She's in with a male cherry finch and they're sharing incubation of some eggs together, taking turns.

Anyone know how she could have lost all those feathers? She literally has bald patches.

[Sally]

I don't think too many of the US forum members have Cherry finches, so hopefully someone from an area where they keep them will be able to help you. The only thing I can think of is the male (or even the hen herself) plucking to add lining to the nest? Or do Cherry finch males get aggressive during breeding time:

[finchbob]

I heard that cherry finches do get aggressive during breeding, so I was told to keep them in seperate pairs in their own space. The male who is with her shows his aggression every time I go into the room where he is kept, he will squark rampantly at me until I go away.