It is indeed normal for a female budgie to mount a male budgie. This behavior can be confusing to new budgie owners, but it’s often a natural part of their social and reproductive interactions.
Mounting, also known as 'treading', primarily occurs between mature male and female budgies during the breeding season and is intended for mating. The intention is very clear. However, 'mock mounting' can occur regardless of gender or whether the birds are in breeding condition, even between two females or two males. Interestingly, there seems to be a higher rate of same-sex relationships among budgies. It's not uncommon to see two females, when housed together, become highly affectionate, engaging in mock mounting, and even laying infertile eggs. So, a female budgie mounting a male is perfectly within the normal range of budgie behavior.
Signs a Female Budgie is Not Interested in a Male
If a female budgie is not yet mature, has no intention to breed, or simply isn’t interested in the male, she will protest with rapid, soft clucking sounds. The male budgie will perform his courting rituals, including regurgitating food and trying to coax her into the nest box. However, the decision to breed depends solely on the female. The behavior of the male is secondary to the female’s willingness. Budgie breeding is mostly determined by the female budgie, not the male budgie.
Normal vent (left) pre-breeding and swollen vent (right) during breeding/egg laying. Female budgies play a deciding role in the breeding process. It is important to know if the female is in breeding condition. A female budgie who is ready to breed will begin investigating the nest box. At the same time, you can observe her cloaca opening, closing, and swelling. If the cloaca doesn't demonstrate these characteristics, it's a good indication that she is not prepared to breed. Monitoring her behavior is crucial to understanding her willingness to breed and to provide the best care for your pet birds.