Why are my pet birds fighting and injuring themselves? What to do?

If they were fighting or your older bird was causing distress to the new one, I would wait and try introducing them again later to see how they get along. It could be that the cage you have is too small for two birds and they are being territorial, or your older bird is just stressed out by the change. Making sure the cage is large enough, and there are multiple food and water dishes available so they can't be possessive over one or the other can help reduce fighting. Adding in extra perches along with barriers such as toys or clothespins can also help break up the space to avoid one bird chasing and picking on another.

It would be best to separate each pair into their own cage as the birds may begin to fight over territory, food and water, perches, and shared nesting areas, which could lead to injury. If you don't wish to have babies, removing the nesting material and any eggs should resolve the issue. If you do wish to breed them, making sure the birds have a calcium supplement such as a cuttle bone can help prevent egg binding and produce healthier eggs in addition to a regular balanced diet.

I'm sorry to hear about the loss of your bird. It is possible the male became frustrated, or there was competition over shared resources such as food, water, bedding, etc, that led to a fight and the death of your female if it appears she was attacked by the male. Making sure birds have enough space to move around and access food and water safely is always needed, as well as slow introductions when two birds haven't been together before or in a long time. It would probably be best not to introduce another bird to your male, and to instead focus on enrichment in other ways such as adding in puzzle toys, treats, fun things to interact with, etc, instead of adding a new bird that may stress him out or cause competition.

Thanks for your question about your budgies. It isn’t typical for the pair to start fighting, but it wouldn’t be unheard of either. I didn’t see if this was their first clutch together, but sometimes that can make a difference. I would recommend ensuring that there is a great deal of space for them to get away from each other, and lots of resources available. Multiple food dishes, numerous hiding spaces, etc. Also, keeping any additional stress to a minimum would be important - things like new people coming over, loud sounds, etc. I hope this gives you a place to start, and thanks for using Petco Pet Education Center, formerly Petcoach.

If the aviary is too small to handle multiple breeding pairs it may be that they are competing for nesting space, even if there are multiple nests. One nest may be seen as "ideal" and thus everyone is fighting over it. Usually, birds are separated into individual breeding groups per cage to avoid competition and ruining of eggs, as well as reduce overall stress for the breeding pair.

It is good that you separated the bird being picked on. If he is actively bleeding, injured, or the sites of his wounds appear to be infected, then it is best to bring him to a vet and have him treated with antibiotics as needed. Until you can get to the vet, keeping him separate, cleaning any wounds of any debris or oozing, and preventing him from picking at the wounds can help some.

It may be a dominance behavior. Consider a larger cage for them with additional food and water bowls to prevent resource protection. A concrete perch or sandpaper perch wraps may help keep nails trim. You can also clip them yourself or have them clipped if you have never done it before. If the behavior persists or worsens, you may need to cage them separately to prevent injury.