Male bullying female Zebra finch

Question
I've had a male and female Zebra finch pair for about 5 months now.  The female seems to be a chronic egg layer, and they had taken care of several bunches of eggs that were not fertilized and never hatched.
Originally, the female would become aggressive towards the male after I had removed the eggs after a week or two.  Now (about two weeks after I removed their last nest) the male seems to be bullying the female badly.  
He chases her away from their food, treats, and cuttlebone, and looks to be grooming her so aggressively that she is losing the feathers above her beak.  I am also afraid that she is losing weight, because of the egg laying before and now because her mate is bullying her.
What should I do?  Separate them, or introduce another female?
Thank you!

Answer
That isn't aggressive grooming, he's pulling her feathers out. You need to separate those two immediately and decide what you want to do with the male. You can try keeping him by himself in another room but I find that only works on the rare occasion.