[KimBear]

You can't make parrots get along, but you can do your best to get them to the point where they will tolerate one another, and there's always that chance that at some point they may become good friends. First of all, realize that since you've only had the macaw for a week, everyone is still in the getting-to-know-you phase, and it's understandable that the two birds aren't jumping to be best pals. Let the macaw settle in, and let your cockatoo get used to the idea that he's not the only bird in the house anymore. If he seems to be jealous, be sure to pay extra attention to him but don't react too much if he screams at or otherwise acts hostile to the newcommer. You don't want to accidentally reinforce unfriendly behavior, but nor do you want to punish it. It's perfectly normal for things to be a bit tense for a while.

If you've already got the macaw in the same room as the cockatoo (it would have been better if you had quarantined the new bird but what's done is done), leave it at that for now. Putting the cages too close together may be a bit much at first, for both parrots. After it seems as though tension between the two isn't as high, you can move the cages a bit closer.

Once you see signs that they're tolerating one another, and possibly even curious about eachother, you can try introducing them outside their cages, in a neutral place. Put them both down several feet from eachother, and be right there to step in if someone decides to get too pushy or is outright mean, or if you sense that either bird is afraid. The idea is to get them to be comfortable together, and fear on anyone's part won't help at all.

There's no way to know for sure how long it may take before you feel they're ready for this kind of interaction, but I'd error on the side of caution and not rush things. If you plan to have both these parrots long-term, you have lots of time to let them decide if they can be friends.

If I had to guess, I'd say that the odds may be in your favor, because many parrots often enjoy the company of other parrots. Not always, though, so take it slowly.