Meeting Abstract

P1.2  Monday, Jan. 4  The effect of female ornamentation on aggressive male-male interactions in the striped plateau lizard (Sceloporus virgatus) DUBIN, Matthew E*; WEISS, Stacey L; Univ. of Puget Sound; Univ. of Puget Sound medubin@gmail.com

The intensity of male-male competition is hypothesized to be influenced by the quality of the contested resource. When competing for females, that quality may be signaled with sexually selected female ornamentation. In the striped plateau lizard (Sceloporus virgatus) females develop ornamental orange throat patches before ovulation, and previous research has shown that the more ornamented females are of higher phenotypic quality and also produce offspring with higher phenotypic quality. Therefore, we hypothesize that variation of the female ornament influences the intensity of male-male competition. Beginning approximately twenty days before ovulation, lizards were captured and held in groups of two males and one female for five days, such that all three lizards were in separate cages and the males could see the female but not each other. Males were then placed in the female’s cage and videotaped for twenty-minutes (n = 51). Male aggression was quantified using an ethogram and each aggressive behavior was weighted using Principle Component Analysis. Male aggression was found to be uncorrelated with female patch area, hue, brightness or chroma (p > 0.05). These results indicate that male-male aggression during the breeding season is not influenced by the female ornament. Past research has found that the intensity of male-male aggression increases in the presence of a female. Further research is needed to determine how variation in the intensity of male-male competition is influenced by female or environmental cues.