Sexual Dimorphism and Patch Size Variation in Three Lizard Species Suggests Potential for Sexual Confusion

Abstract

In lizards, signal patches play a role in sexual selection, both in interactions among and between sexes. The size and shape of a signal patch may be used by males to determine if another individual is of the same or opposite sex. Males may confuse other males for females, or vice versa (i.e., sexual confusion) if the signal patches overlap in size and shape between males and females. As a result, the confused male may perform courtship displays to an intruding male or display aggression toward a female. Sexual confusion has been documented in Sceloporus cowlesi and is attributed to overlap in signal patch morphology between the sexes. But it is unknown how common this pattern is among other Sceloporus lizards. To make inferences about sexual confusion at the species level, we compare the morphology of signal patches between males and females in three species of Sceloporus lizards (S. consobrinus, S. cowlesi, S. tristichus) to test for adequate differences in signal patch size to prevent sexual confusion. Our results suggest that due to similarities in patch size between the sexes of both S. cowlesi and S. tristichus sexual confusion may be occurring.