Help with an aggressive finch?

[Crow]

I have one society finch that is quite old. We got her from our neighbor when she moved away... Her siblings were given to other families. We got her another finch to start with, a male, and they got along fine for a month or two. We figured we would let them bond before getting other finches, since our first was so much older.

Anyways, a few months ago, we got two more finches - a female zebra finch and another male society finch. Again, all of them got along well... The new society finch settled right into their nest, and though it took longer for the zebra finch to be accepted (they kept letting her stay in the nest one night then kicking her out into the spare nest the next), until recently all was well.

But now the first male finch we got as a companion for our old girl is attacking her. It's been going on for a week or two, on and off - she would hop into the nest and jump out immediately with a chirp, and the male would chase her around the cage He always forces her onto the floor of the cage and dives at her, making her screech... Sometimes he seems to tolerate her, but other times he pecks and pecks.

What happened? Why did he suddenly develop this aggression? And how should I handle it - do I separate him from the others? And if so, for how long?

Thanks for the help. I'm pretty new to finch ownership, so I'm not sure what to do...

[ac12]

Seems unusual that a society would behave like that.

Immediately remove that male, and put him in "solitary confinement."
After a couple weeks, put him back. If he does not behave, remove him and consider giving him away.

It might also be a situation where that male has rebonded with the other male society or the female zebra, and does not want the female society around.

How is the 2nd male society behaving?

You may also have to separate them into pairs. 2 in one cage and 2 in another cage.

[cldheath44]

Have you looked in the nest to see if there are eggs in there? Maybe he paired with the female zebra and they have eggs in the nest that he is guarding?

Christine