Hi,
Actually your male is still too young to be paired with a female. Cockatiels should be at least 2 years old before you put them together. Young birds do not make good breeders and tend to develop bad habits that ruin them for ever being a good breeder. You need to separate these birds until you are sure both are 2 years or older. A young hen is at a high risk of becoming egg bound and dying of she is put with a male too soon. Both birds may be capable of breeding, but they have not finished developing physically or emotionally. The males tend to only be interested in mating, and will break or eat the eggs to get the female to mate again. The female’s reproductive track is still developing, and the muscles she needs to move the eggs through her system are not strong enough, so the egg can get stuck and she will die.
As for the aggression, breeding birds can’t be pet birds. If you want them to be tame, then do not cage them together and never try to breed them again. Breeding birds need privacy and should not have human interaction. They need to focus on each other. When you try to handle a breeding bird, it causes confusion which results in aggression to the human and the mate. In some cases a bird gets so conflicted that it ends up killing the mate out of frustration over whether to be loyal to the mate or the human.
Since they aren’t old enough, and need to be in separate cages until they are, you have time to think about whether they will remain pets, or become breeders in the future, meaning no more handling. As for the male being in “heat”, there is no such thing. Birds will get hormonal when the right triggers are present – longer days, warmer weather, abundant food, and a safe, private place for breeding. They do not have heat cycles. If your male is hormonal right now, he will settle back down, especially when he isn’t sharing a cage with the female. You can avoid triggers by limiting light to 8-10 hours a day, don’t let either bird roam freely – this mimics searching for a nesting place. Limit the fresh foods to a few times a week. Never pet your birds below the neck and do not cuddle with them. Keep them out of any dark, cozy places.
Research is good, but do not get your information from social media. Learn from experts like myself, not the average bird owner or videos you see online.
Thank you for asking Lafeber,
Brenda