I just watched this on animal planet's "Planet Earth". Look at the amazing coloring on the males. I've never seen anything like that!
I read an article about them that explains that sometimes males who have gone rogue will mate by intercepting a travelling female, and basically jump on her and rape her. To avoid this, the female lizards stay by the dominant, territorial males. It made me laugh because it's so personified. It's like when a chick goes to a bar and brings her muscle-y boyfriend so that all the scum bags stay away. hahaha.
http://youtube.com/watch?v=6sWS6WUxvjw