I wanted to report on the amazing things that have happened with the budgies who share my life.
After 3 weeks of cages being kept on opposite sides of the room, I moved Twinkie's cage (Twinkie is the new addition) about 4 feet from Peek and Boo (who I've had almost 2 years). At 3 weeks, Twinkie had begun sitting on different perches, playing on her 3-ring rope chain, and occasionally making a chirping sound. (For the first two weeks, she was utterly silent and rarely moved from her little mirror with the beaded wire.) With Twinkie's cage closer, Peek and Boo (Peek especially) would look over at Twinkie occasionally, although Twinkie didn't seem to notice the other birds existed.
After another week or two, I moved Twinkie's cage about six inches from Peek and Boo's. WOW. That made a huge difference! Peek began walking up and down over the wall of the cage that faced Twinkie and sometimes squawking when Twinkie was eating, the same way she squawks when Boo eats. Peek also began doing somersaults over her pine perch and the comfy clamshell, which was new behavior for her; Twinkie, however, had been doing somersaults on her 3-ring rope chain. Twinkie began grabbing and shaking her hanging toys, which was new behavior for her; Peek and Boo, however, have many toys in their cage that they shake and chew. So there were all kinds of back-and-forth copycat behavior beginning. So exciting!
Twinkie also began climbing on the cage wall that faces Peek and Boo, so she definitely noticed the other birds existed!
Last weekend, I opened everybody's cage doors so they could come out and meet if they wanted. Everybody stayed in their cages.
Today, I did the same thing. This time, Peek came out of her cage and walked all over the outside of Twinkie's cage! I stayed nearby in case they got nasty with each other, but Twinkie did the head-bobbing thing and they seemed to be trying to feed each other through the bars. Once Peek returned to her cage, I placed the cages very close together, maybe half an inch between them. Since then, Twinkie has been making the squawking noise occasionally and flapping her wings the way Peek does (Peek holds onto the perch and flaps her wings like she's trying to take off with it).
I have been so gratified at how Twinkie has become more vocal and active!
That's great that you're seeing such good progress - very exciting! It sounds like you have been patient and cautious introducing the birds to each other. I'm making a mental note to try what you've done since I would like to introduce my two budgies as well.