I have a 10 month old cockatiel who I'm pretty sure is a girl. If I were to introduce a second bird to keep her company, I've heard it's better to introduce one of the same species. But when she begins to lay eggs, what if I put an egg in there... of a completely unrelated bird? Say if I were to put a lovebird egg in a cockatiel's nest, is the mother likely to adopt it as her own? Would the size of the bird affect this? Say having a budgie egg compared an indian ringneck.