Fluctuating asymmetry is a population phenomenon of random deviation in a morphological trait. Some researchers think that fluctuating asymmetry reflect an indirect measure of fitness. This is because sexual ornaments are under intense directional selection. The sexual ornament displayed, the degree of fluctuating asymmetry, reflects the male's ability to deal with environmental and genetic stress, thus as an observer, there is a compromise in males between tail length and symmetry. The tail length itself is the strongest predictor of mating success. However, when the tails were experimentally manipulated, comparing a shortened tail to the control, these males had equal success in acquiring territory with no difference in size or quality. The long-tailed controls spent less time flying and performing courtship displays and they attracted higher quality and more nesting females compared to short-tailed males.