When the quarantine period of 4-6 weeks is over for your new budgie, you will want to keep both budgies in their cages and place the cages next to each other. This gives the two birds a chance to interact (at a safe distance) and realize that there is now a new budgie in the house!
After a couple of days with the cage next to each other (use your judgement for time), you can introduce the budgies in a neutral area. Neutral areas include a playground or playgym, someplace NOT inside of a cage.
Never introduce budgies by putting one inside the other's cage -- always introduce the two in neutral territory.
Putting a new bird in another's cage can cause tension and aggression between the two. The bird currently occupying the cage may become very territorial and try to protect his "home" from the "intruder".
Watch how the budgies interact.
If they are at all aggressive (blood being lost, feathers being pulled out), immediately separate them back into their original cages.
It is normal for a little bickering to occur.
There might be some squawking, chasing around, or odd budgie noises. To make things a little less tense, give them both some millet, and then reduce it to one stick to see how the budgies react.
If the budgies seem fine on the playground/neutral area, you can then move them both into the same cage.
If you move them into a cage previously occupied by one of the two budgies, make sure you rearrange it so it looks different and foreign to both birds. This will help prevent any territorial feelings coming from one budgie or the other.
The new cage should be as large as possible. At the very least, it should meet the minimum recommended size for two birds.
Include a variety of toys (ropes, bells, ladders) and perches (rope, swing)
Ensure you have separate food and water bowls for each budgie. Place one set of food and water dishes each on opposite sides of the cage
Once the two budgies are in their new cage, keep an eye on how they are doing. All new budgies will fight a little (but not too violently) and bicker to establish who is the "alpha" budgie. This 'bickering' should go on for at most couple of days, but then settle down.
If you notice that one budgie is agressively bullying or injuring the other, you will need to separate them back into two separate cages. You can try a reintroduction again a week or so later.
If you are interested in taming one/both of your budgies, you will want to work with them separately in quarantine and when they are together. After about a week of the two budgies being together, only then should you start training them. Work patiently with 'stepping-up' (even if one of your budgies has mastered that step when he was alone) and start back from the beginning of the "training book". It may be frustrating and your budgie may bite you (he's scared you'll separate him and his new friend), but keep with it! Once one budgie begins to show trust, the other one follow his example.
I did all the above with my 1st pair. It worked really well. But the older bird never wanted to share a cage. In the end it was outside the cage where they got to know each other. Over time they became friends but not too close.
I introduced my 2nd pair outside the cage. Outside the cage they were able to fly away from each other and be safe. They maintain their own cages until they are comfortable to share. I have the big cage open all day & now after a month the small cage is away during the day. In the last 3 days the baby has been exploring the big cage on his own & really seems to find everything entertaining. So much so that our other Budgie [who dislikes cages] has played inside as well.
We offer separate feed & water stations as well but outside of the cage we encourage them to forage & there they have to learn to co-operate. They learn there is is enough for all & we learn not to overreact to their bickering & displays. They also have a great time hunting for their food. It is quite lively. Special treats have to be offered one per bird or on a very big plate.
Excellent information Alexandra It is definitely sticky worthy
I would like to add...
When it is time to place your budgies together in the same cage, I do encourage people to re-do the entire cage before adding in the budgies. By rearranging toys, perches, food bowls, and other objects in the cage, there will be no "marked territory." The rearrangement makes it so that the cage is neutral, rather than "owned" by the budgie that had been previously placed in the cage.
Also, when it comes to training your budgies together, it is ideal to train them separately, but it is also a good idea to train them together. Like Alexandra noted, when one budgie starts to warm up to you, the other will usually follow along. Budgies are generally, "monkey see, monkey do." By training them together, you're allowing yourself to be one of their flock. It is great to have one best friend, but it's even better to have a group of friends too, right?
I definitely agree with the rearranging of the cage. Most often owners will have their birds introduced properly in a neutral area, and the birds will get along. But then, they'll place both of them back into the cage that looks the exact same. The one budgie, of course, will become territorial all of a sudden and aggressive to the new bird. If you rearrange the cage, and add some new toys, ladders, and perches, that reaction may not happen as much.
Aaralyn added a great point about the training, too! Thanks!
I just pulled my two new babies out of quarantine yesterday, and their cage has been sitting next to my older birds -- everybody is very interested in everyone else, and there's a lot more activity now than there was before.
Today, I let everyone out of their cages with two playgrounds side by side. They all 'jumped' at the chance to meet. It's pretty clear my older female Alice is going to be queen of the castle. She spent some time showing everyone who is boss, but was always willing to come to me for some finger/millet time and calm down.
Right now, I have both cages open so everyone can retreat if needed. So far the older pair have gone in to check out the newbies cage, and the newbies made a couple of attempts to get into the bigger cage, but were chased out. They're curious little budgies, so I'm sure they'll keep trying.
Everyone is chewing a lot more, fiddling with toys they used to ignore, shredding shredders like crazy. Is this an expression of the excitement/stress of the change in their lives? Or are they just so happy they have more energy?
I hadn't thought about changing around toys in the big cage to make it a little less like 'home' to my original pair. That's a great idea, and I'll go do it right now.
Is it ok to leave both cages open and next to each other and let everyone move into the big cage on their own? I have already removed treats from both cages, and put them in the playground area, so everyone gets an equal shot at them. (And to encourage everyone to come out and play.) I figure that if I just don't refill the food quite as quickly on the smaller cage, but the bigger cage is getting fresh food every day, everyone will eventually prefer that cage and I can remove the quarantine cage. What do you think? I intend to close up the birds in whatever cage they're in at night, or when I have to go out and leave them unsupervised. (House rule. No loose birds without an adult to keep the cats away. Doors don't always stay closed.)
This felt like the least stressful way to introduce them. Any comments or ideas?