If you are colony breeding your budgerigars, they pretty much choose their own partners. Cage breeding is a different matter as you choose the two birds that are to breed together. Breeders use several variations when it comes to introducing the pair to the breeding cage. Cock bird first, hen bird first, both together. The time between introducing the birds to each other also varies from a few minutes to a few days. In practice, this seems to make little difference and a pair of budgerigars in breeding condition just want to get on with the job in hand.