I've Kept Cockatoo's before. First off, they need to have almost nil Nitrate's as they are dead sensitive. Second, no 2 males cannot be kept together. Third, im pretty sure they only have one mate, but they might breed in Harem's. No they arent easy to keep. Make sure you keep the water Clean, Clear and safe. They are terribly sensitive, and most cockatoo's availble are babys as breeder's try to get rid of them as soon as posdssible. Also, baby's are even more sensitive.