I asked this same question last year and unfortunately, they do not neuter birds but 1. DON'T get one of those "cozy" hide away beds or those ones that look like a nest because that will encourage them to breed there. My vet, and what I read, said to not provide any "nesting" conditions in their cage, and when the female's cere turns brown and crusty and the boys is a really dark blue, seperate them for a while. You can trick them into thinking it is winter by covering their cage at 4:30 pm and keep moving their cage to different rooms during breeding season, so they are don't feel "at home" in one spot. The only problem is once the female's cere turns brown, it pretty much stays that way, so, like now, I can't tell if my girl is in breeding mode because her cere has been brown for 9 months. I hope these tricks work for mine as well because I cannot have baby birds either..I already have 4.