Hi Shad!
Happy New Year – it’s great to hear from you! The short answer is yes, please separate the sweet female from the pair. You are very lucky the parents, particularly the breeding hen, have tolerated this intruder. Many breeding hens would have already launched a vicious attack and possibly killed her! And most breeding males may have tried to mate with the new female, starting up more territorial fighting. In some cases, the breeding pair will destroy their eggs or abandon or kill their chicks in the case of an intruder. This would not be tolerated in the wild – breeding pairs defend their territory and a rival would be attacked and driven away. In your situation, you also do not want the single female to start laying eggs. Single female cockatiels are known for becoming chronic egg layers in captivity and in some cases, they need a Vet to administer a hormone shot or implant to stop her from laying or she will eventually die from laying too many eggs. Even though the pair has tolerated your other female to this point, the situation could turn tragic with no warning. Dr. Tully actually discussed unusual pet bird interactions in his webinar last month. He brought up the many photos and videos you see on social media showing pet birds interacting with other pets or interacting with other pet birds that are much different in size. He pointed out that while these interactions seem cute at the time, each one is a tragedy waiting to happen as all it takes is a bite from a pet dog or cat, or a large parrot biting a small parrot and when that happens, the bird rarely survives or if it does, it is permanently disfigured.
Congratulations on your Christmas Eve chick! I hope all continues to go well and I’m sure the parents will be relieved that your sweet nosy female isn’t bothering them anymore! 🙂
Thanks for the update,
Brenda