Hi Signe,
Your male isn’t old enough to breed yet. Both birds should be at least two years old. Since she is older than him, giving them a nest box could actually cause her to get aggressive with him. She is mature, he isn’t, and she is already showing some signs that she is frustrated with him in that respect. If her hormones kick in to the point that she wants to mate with a mature male, she could actually end up killing him because he is simply in the way. So it’s best to discourage any nesting or hormonal triggers. I would recommend some changes to help, at least until he is 2 years old. You also need to think hard about breeding, because it means you can’t handle them anymore. You basically end up with a pair of birds that need privacy and a lot of healthy foods. Then you have chicks to find homes for if they produce, because you can’t keep the offspring with the parents and you can’t keep related chicks together or they might try to breed. Breeding birds isn’t easy, and you are likely to lose eggs or chicks while the parents are learning. And some parents never get it right. So you have to be able to handle the down sides and understand you might never be rewarded with chicks. But of course if you are, it makes the hard work worth it.
You need to do all of these things to discourage egg laying & breeding behavior. Keep in mind that to lay eggs, she needs longer daylight, warmer weather, abundant food, and a quiet, private environment. Your goal is to reverse these conditions.
Limit their light to 8-10 hours by covering the cage early each evening
Do not give them anything to use as a nest – no bird huts or tents, no box, bowl, etc. If she decides to sit in a food bowl, remove it and replace with smaller cups.
Do not give them anything to shred such as paper or cardboard.
Rearrange the toys in the cage frequently.
Move the cage to a different place in the room. Move the cage about once a week, or whenever she shows signs of nesting – settling on the cage floor for example. This disrupts her idea of having a stable place to lay eggs and raise chicks.
If you feed a lot of fresh foods, stop offering any for a couple of weeks, and then only offer them in small amounts about 2 or 3 times a week. You can resume normal feeding later when the birds aren’t being hormonal.
If she is let out of the cage, do not let her get in any dark cozy places and don’t give her free roam.
When you handle them, limit any petting to only the head and neck – do not pet either bird on the body. Only a bonded mate is allowed to groom the body. We can’t be a mate, so touching the body is off limits.
If there is no metal floor grate, then do not use any bedding or paper in the cage tray – leave it bare and clean it daily.
Thank you for asking Lafeber,
Brenda