I used to have two macaw hens, a GW and a capri hybrid. I was lucky: my girls liked each other. They could play, eat, bathe, and squabble together just fine. A friend of mine had a scarlet, a hy, and a harlequin, all hens. They couldn't stand each other. If you get another bird, it better be for you. If you're lucky, they'll tolerate each other. If you're extremely lucky, they'll be buddies. Even if they don't like each other, they'll become a flock. My DYH never liked my other birds; once, she tackled Daff, the capri, in mid-air. However, she would contact call when they were out of sight and talked to them.