The Function of Breeding Coloration in the Lizard, Sceloporus virgatus

Abstract

During the non-breeding season mature females of Sceloporus virgatus have blue throat patches and closely resemble males in coloration. During the breeding season orange coloration surrounds or replaces these blue throat patches, and the orange is most intense when the female is gravid. In discrimination tests males courted females with either orange or bluepainted throat patches. Resident males made more mistakes in sex recognition of introduced male lizards with orange than with blue-painted throat patches, and of introduced females with blue than with orangepainted throat patches. The responses of non-gravid females are similar to the reactions between agonistic males and different from the responses of gravid females. The changes in response and color probably facilitate sex recognition by males during the breeding season.