I’m not sure how old your female is, but your male is just now old enough to be set up for breeding. If the female is not at least 2 years old, then you should remove the nest box and wait until she is old enough. When the birds are allowed to breed too young, they make mistakes or fail to settle down to care for the eggs. A young female is also at a high risk of becoming egg bound and dying. If she is 2 years or older, then mainly you just need to be patient. However, the other birds may be too much of a distraction or threat to the pair, so that may be part of the problem. Cockatiels need a nutritionally balanced diet, especially if you want them to breed. They need to be eating pellets or our foraging diets – a loose seed mix will not provide the nutrition they need to produce eggs and healthy chicks. In addition, you should offer dark leafy greens, chopped veggies and to get them in breeding condition, you should also offer cooked eggs with the shell washed, crushed and cooked with the eggs and some multi grain bread. These last two foods should be given to them from the time they have the nest box until the chicks are weaned. Cockatiels need privacy for breeding – having other birds around may keep them from breeding and checking on them too often is not good. The nest box should be attached to the outside of the cage as high as possible. If the pair does lay eggs and hopefully hatch chicks, the nest box must be removed as soon as the chicks leave it. If the eggs do not hatch, the nest box should still be removed. The pair needs to be rested for about 6 months between every clutch. You can allow them to lay eggs twice a year, which is one more time than they would in the wild. If you do not control how often they breed, they will literally keep breeding and laying eggs year round, and this will eventually kill the female. It takes a lot of patience to breed birds. You should make sure they are eating a good diet and have everything they needs, and then all you can do is wait and hope they breed and lay eggs.
Thank you for asking Lafeber,