Of course, males need not be harrassing the female to incur female aggression. In many cases, females will nip at the male and drive him off. By co-opting the female rejection display, yellow males use a dishonest signal to fool some territory holding males. The ruse of yellows works only on orange-throated males. Blue-Throated Male Behavior Blues are not fooled by yellows.
Blue males root out yellow males that enter the territory of the blue male.
Blue males are a little more circumspect when they engage another blue male during territory contests. Blue males spend a lot of time challenging and displaying, presumably allowing males to assess one another. Attack may or may not follow as blue males very often back down against other blue males. Indeed, Neighboring males use a series of bobs to communicate their identity, and the neighbors usually part without battle. Orange-Throated Male Behavior Orange males are ultradominant and very aggressive owing to high levels of testosterone, and attack intruding blue males that typically have more modest levels of testosterone.