Lonely middle aged cockatoo?

Hello everyone! My parents' umbrella cockatoo, Calla, is a sweet, shy, and gentle 30-40 year old. She was adopted in the 80s, and has had two bonded mates/friends since then. Both mates/friends are unfortunately no longer with us. First was my grandparents' male moluccan cockatoo, Sammy, who didn't live with our bird, but had frequent visits. After Sammy died, Calla began picking herself. This habit never really went away. The next bird Calla bonded with was my dad's female green-cheeked amazon, Gypsy. Calla and Gypsy lived in the same cage for 15-20 years, and they were best friends. The only issue was that Calla extended her picking habit onto Gypsy's head, so Gypsy always looked bald...poor thing. Gypsy died about 10 years ago, and since then Calla has been alone.

I've tried to convince my parents to find a friend for her, because she seems so lonely. She's only happy in front of a mirror, in her outside cage with wild birds (sparrows, hummingbirds, etc), or bothering one of our dogs that she somehow bonded to (though Skye doesn't care for her at all). Since Calla still has 20-30 years left in her life, I feel like she would benefit from another friend. I've suggested looking for a middle aged or elderly rescue bird, but my parents do not want to invest the time, effort, and earplugs into another large parrot.

So my question is this: are there any small parrot breeds that are compatible with cockatoos? Budgies, cockatiels, conures...? I know you can never tell how a bird will be with another bird, but Calla is the sweetest, gentlest creature (her nickname is "Bunny"). She loves the little birds that come visit her through the bars of her outside cage. I just want her to have a fulfilling and happy life. Thanks in advance for your advice!

What a touching situation, and thanks for caring for Calla so intently.

Calla has such an interest and proven bonding potential it would be a pity to deprive her of avian companionship. While it is tempting to experiment with other small parrots in close proximity, the realities of disease prevention and quarantine protocol make this problematic.

I don't know of specific species that are known to be compatible with large Toos, but hopefully others may have better advice.

I do think she may need a friend. My friends Goffin cockatoo is beast friends with a budgie! They found it in the yard and after a while they put the keet in the Goffins cage and now the cockatoo stopped her plucking! The little bird is therapeutic! So maybe? I think if you brought Calla to a bird shop and had her pick out her friend, I think she would like that! I wish she could have another big bird with her...

Thank you so much for caring about her so much And if you do get another bird, quarantine and vet check up is a nice thing to do

But if you do get her a little friend, please don't put it in the same cage. I don't think it was a great idea to put the parakeet in the cockatoos cage but I cant tell them what to do... So if you get her a friend, it would be best to put it in another cage next to Callas cage. There is a bit of risk in homing two different spices of birds together sadly :\