I have a large indoor aviary that houses 18 cockatiels. Spikey, a normal grey male cockatiel, and Blondie, a pied male cockatiel, have been best buddies for years. Blondie slowly bonded with Frosty, a female cockatiel. Spikey has become aggressive. Spikey and Blondie get into terrible fights, and I frequently have to separate them. What should I do for my cockatiels?
For the safety of your cockatiels, I think it’s time to separate them. You have several options. One, you could take cockatiel Frosty out of the aviary and bring her in as a pet cockatiel, then the boys can go back to being buddies without the influence of a love interest that has broken up their relationship.
Two, you could separate the male cockatiels and put them in a cage of their own; or, three, separate Blondie and Frosty into one cage, and give them a chance to build their relationship. If the cockatiels continues to have fights, you could put them into three separate cages.
If you separate the aggressive pet birds now, you can reunite them in mid-summer and over the winter when breeding season has passed. It’s natural to have times when pet birds congregate in flocks and other times when they pair up to raise families.
It’s also natural for a male cockatiel to act aggressively toward its mate when there is danger around. Spikey feels protective toward Blondie, so he rather aggressively drives him away from other birds and from people. Spikey is probably frustrated that his cockatiel suddenly has his eyes on another bird.
I had a lovelorn cockatiel injure its intended mate when it could see but not get to the object of his affection. I know that displaced aggression and frustration can cause injuries, even though cockatiels are normally peaceable birds. That is why I suggest you segregate Blondie and Spikey or set up a separate cage for your trio if they can get along without the outside interference of other birds. Trios of cockatiels can get along, but only if all the birds agree. They can even raise a nest of chicks together with the "aunt” or "uncle” helping incubate eggs and feed babies.