Here's the story: About 5 years ago I got a cockatiel from a friend. She told me the cockatiel was a girl. I wasn't super positive about this because there was no striping underneath the tail, which I've been told is the way you tell females and males apart. If the cockatiel has stripes, it's a girl. No stripes, it's a boy. Anyways, I wasn't positive, but I accepted it and called my bird a "she". About 2 1/2 years later, I went on vacation and left my tiel at a friend's house. This friend also had a female tiel. I came back from vacation only to be told that "she" had tried (never actually succeeded being the key phrase here ) to mate with my friend's bird. So, I started calling my tiel "he". Now, a couple of days ago, I caught my male PARAKEET in the act of mating with my tiel. Now I am having serious doubts as to my bird's gender. I thought that it might be possible that my tiel was just doing a dominance thing with the other tiel, and the stripes of a female just don't show up on this one? I have heard about mounting as a dominance display between two female dogs, and seen it before in two female guinea pigs, but I really don't know. PLEASE HELP ME SOMEBODY!