I've had pet cockatiels for a while now. About 5 years ago we got what we thought was a female and then about 3.5 years ago we got another one which we thought was a female. We were never sure though and when I finally moved them from my parents home to mine I took them to the vet. He told me by looking at them that he thought one was male and one was female however they have never done anything. Well at least they hadn't until the other day. They have started mating and I'm not sure what to do. I don't want eggs but I can't simply get rid of one because of their temperament (not too friendly..The first one was rescued from a "friend".) I don't want the eggs to just die but I really which I could just stop them from mating. Once again we thought they were both females (bought the second from petsmart and its the male). They are for sure trying to mate and I can not get rid of one. Any advice.

Separate them, get another cage.

Don't have a nesting box if she lays eggs replace them with marbles or fake eggs and she will sit on them. Keep moving the cage every couple of weeks get new toys take them out of the cage for a few hours every day. The constant change will deter the mating behavior.

Breeder