I have two Royal Palm poults and I'm thinking they are a pair. They are both only about 3 weeks old, but one has grown out black markings on his feathers already, while the other is almost still a solid white. But watching them, I can also see a difference in their personality - one is definitely more aggressive than the other. They also have different voices, as one is MUCH, MUCH louder! Although I'm really hoping to get their large outdoor pen finished before the parrot living in the same room, practices chirping enough to sound exactly like them.... (yes I've caught her practicing many times already, but it doesn't match yet).