Tonawanda News —
I think it would be a wonderful idea for you to adopt Rosie, especially if you can provide her with four to five hours out of her enclosure daily, like you do for Forrest. That sounds like a great companion parrot home.
I agree that leaving them alone to deal with their issues might not be the best solution, especially if
Rosie is the one that is being aggressed upon, since she wasn’t encouraged to use her flight skills at her previous home. It would appear that Forrest would have the advantage of flight and the lay of the land, since he was at your house first.
One thing to think about is to try and avoid circumstances that illicit aggressive behavior. This could include not allowing either bird on the other’s play gym for the immediate future. You mentioned that they do well when they are each on a different person’s hand, which I believe is the solution for the time being.
When they are in the same room out of the enclosure, keeping them on someone’s hand, while at the same time reinforcing with head scratches or treats, whichever they prefer, for calm behavior is a great alternative behavior to train. You can also reward them for rousing (fluffing feathers), turning their head away from one another or opening their wings. Rousing is often seen in birds that are very comfortable with their surroundings. It is similar to a bird taking a bath; they aren’t going to bathe if they feel threatened, it wouldn’t be safe.
Before I would introduce them again, I would start to slowly move their cages a little closer to one another. If it has already been a week and they seem to be doing well, move their cages another foot closer and see how they react. Keep moving their enclosures together until they are 10 inches apart and there is no aggression (lunging, eye pinning, hissing etc.) between them.