Everyone is happy to be out together in the kitchen, dining area, bathroom, etc. as long as they are in their "safe" places. There are boings and places to perch separately in the bathroom while I get ready for work. They have separate areas to eat in the dining area (island, counter, and a perch on a faucet). And the kitchen is big enough to have them all out together, but separated. Zeek is not interested in going after any of my conures. You may find that since the other birds were in the household first, the new caique may not have aggressive tendencies towards them. I have Zeek out with the other birds, and also separately. He does get more one on one attn. then the other birds. He insists on being snuggled before bed. "Grooming" is very important to him where he grooms me and I snuggle him, pet him, and groom his feathers. We do this every night. For whatever reason, my boy loves to be snuggled under my chin and carried around like a baby.
At five years of age, your caique may not take to another caique. It is hard to know. I wished that I had gotten my caique the unrelated female he was raised with but I was too ignorant then. Now, because of his age, I have found it is too late. I would be happy if all my parrots were paired, not to breed, but because I feel a buddy or mate can provide the companionship they need better than I. But this doesnt look like it will ever be a reality.
I did recently in fact temporarily bird sit a female caique. The owner and I had hoped that they would get along and that, ultimately, I would adopt her. We both thought that our caiques wanted a buddy. I discussed this with the vet before doing so. After two days, it was clear it was a disaster. Zeek wanted to attack her. I believe that it is because, at 14 years of age, he is too old to accept another caique. He felt that she was competing for my attn. (she was). I was beside myself trying to devote attention to two caiques separately. She was incredibly sweet, but also very loud. I called the owner and, as she had not left on her trip yet, she picked her up. I will not be getting a second caique after this experience. I will say that she was only 2 yrs. old and DID want a buddy. She was also so sweet and adorable. I do miss her after only two days with her and for some reason I feel like I failed her.
All I can say about a second caique is that the risk you take is that you will have two caiques who hate each other and that is not a good situation to be in.
Caiques are not like other birds. You will find that you can handle this bird differently. They have less fear of being physically held, kissed, snuggled. You may find yourself taking him around the house with you while you clean, get ready for work, cook, etc. You dont have to always actively play with him. Just being near you is sometimes good enough. Also, when my caique seems especially bored, I take him for walks around the house and I hold him up to look at things he never gets close to - window frames, the ceiling light, a wall corner, etc. to inspect.
The last thing I will mention is caique aggressiveness. Caiques will always tell you when they are angry. If your bird's pupils constrict, neck feathers ruffled and (sometimes) rhythmic strutting with beak down, then watch out. I will not handle Zeek if he is like this. (I hold a shirt or towel in front of him, which he attacks and latches onto. I carry the dangling towel to the cage and he usually lets go.) My male became aggressive at 4 years of age. He was very angry with me. The reason was clear to me eventually. He was bored. I was also not providing the companionship he needed. He had hit sexual maturity and was no longer a little playful puppy. He wanted a job. He would attack my shoes, my car keys, my sunglasses...things he associated with me leaving. He also would attack my phone (and my face) if I talked on it while he was on my shoulder. I do not let him on my shoulder anymore. After a few years of bloody bites, we finally seemed to figure it out. The dumb human learned to interpret caique anger and avoid bites, purchased the bird a large airy stainless steel cage, moved the bird to a window with more activity, and established a daily routine. I dont know if he is truly happy, but given the bad experience with a second caique, I dont know what more I can do for him. Anyway, I think if you should at least give it a try with the little guy. You are asking all the right questions. Your bird may also never show the aggression that mine does. He also may never be aggressive towards your other birds. If you are able to handle him right now, then that is a good sign.
You could try a foster period. If you keep him, I would think about housing him in the bird room but MAKE SURE THE CAGE DOORS ARE ALWAYS LOCKED. The reason I would consider housing him in the same room is he may like the comfort of other birds around.
Here are some pics:
Cages-I try to give everyone a view out of the window. Zeek is against the wall. He likes it here because he can see out the window and watch for me out the door also.
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Kitchen: Zeek gets the island or counter, while Scout sits on the faucet with the food bowl, and the two smaller conures get the other counter or island.
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Zeek playing on the island:
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Parrots eating lunch:
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For awhile, Zeek liked eating on the floor:
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