I got my first pair of male zebs in mid October. They seemed to get along fine, eating/sleeping together, and preening each other. However, a month later, I noticed bald spots around both legs of one of them. After careful observation, I noticed the other plucking him occasionally (maybe a couple of feathers a day). So I removed the sleeping nest, and got shredding/ pacifying toys. When that didn't work, I separated them in two cages. I bought a new larger cage and moved the plucked one into the new cage. He grew back his feathers in as little as 2 weeks (well I don't see the bald spots anymore but it's possible he can fill out more). Anyway, in the mean time, the other one was MISERABLE without his buddy. He spent all day hopping and flying toward the other cage in futile attempt to get to his friend.
So I reintroduced them together in the new big cage, and saw the agressor plucked his long-lost buddy the following day. The plucking is very infrequent (1-2 feathers a day). It's been two days. Should I separate them again or is it possible that he's plucking now because he's more stresed (from moving the cage) and will be less aggressive later? Do plucking behaviors ever end on their own? By the way, they LOVE each other, always preening and sharing things, just one has a plucking habit...

Thanks for any help!