I agree with Lindamary71. I have a male tiel (Coby) who is around 8 years old and I am birdsitting a female (Trumpette) who is close to 3 years old. From what I understand, Coby has always been a solitary bird whereas, Trumpette, had always had a friend (probably her sister) since the day she was born. At first, Coby didn't take too kindly to having another bird here. I had only had him for about 5 months before I started birdsitting the female tiel. Anyway, I just happened to be on vacation the week I started birdsitting so I decided I was just going to go for it and let them both out of their cages at the same time figuring, if I saw them fighting or not getting along, I could always put one back in the cage and let them out at separate times. I was pleasantly surprised to see they did just fine. The only time he would go to bite her was if she got too close to him. He still does that, from time to time, but she has learned to defend herself and stand up to him now but I always break it up if I see them going at it. In fact, this morning I caught them mating so I guess they don't dislike each other as much as they make it appear sometimes.......lol.