When breeding parrots, you can only have one pair per cage. Otherwise there will be fighting and they are likely to destroy each other’s nests, eggs or chicks.
When breeding American parakeets, if you have a very large walk in aviary, you can try colony breeding. But you will need to set up more nest boxes that breeding pairs, several feeding stations and then monitor them for fighting or nest raiding. The problem with colony breeding is you can lose track of which chicks came from which pair. You never want to allow related birds to breed, so all chicks need to be removed when they are weaned.
English parakeets should not be colony bred – keep only one breeding pair per cage.
Cockatiels and parakeets can live together, in a very large aviary, but they should not be set up for breeding. Parakeets can actually be a lot more aggressive than cockatiels and there is likely to be a lot of fighting and possible deaths.
Breeding birds is not easy, so it is important to do a lot of research and make sure you have all the supplies you may need on hand. This includes knowing how to hand feed the chicks in case the parents will not feed them. Breeding birds need a lot of food, and it needs to be replenished throughout the day once they have eggs and chicks. All weaned chicks need to be separated from the parents or they are likely to breed with them. Regardless of the species you breed, all breeding pairs need to be rested between clutches, which means removing the nest box and in some cases splitting up the pair for a few months.
Good luck & thank you for asking Lafeber,