Re: do birds get jealous?
I have three (males) who do get along and are out of their cages together during the day. In a bird room. YES, I do see signs of jealousy but in their case, they are all still very tame towards me. They all want individual time with me and I give each one that but my first and oldest bird, Oliver, gets the most. I'd had him for 2 years when I added the second two, brothers, and he did not loose his No. 1 position with his momma. They all enjoy each other and human contact, too. There are never any guarantees that any two or three (or more) will get along so introducing them slow and easy and after a full 30 day quarantine is a must. It was a full 6 months before I was completely comfortable that my three would get along outside their cages and I do NOT cage all three together when they are caged at night. The brothers sleep in one cage and Oliver has his own cage at night. Funny thing, they both like him better than they do each other now but I am sure Oliver likes his "alone" time at night so that is our set-up.
Knowing what sex you've got and what you'll be adding is very helpful, too. Males "usually" get along better together than females.
Janie
Oliver, RIP
Big Boi
Shy