Female Residency and Courtship intensity in a Territorial Lizard, Holbrookia propinqua

In the territorial iguanid lizard Holbrookia propinqua territory-holding males were found to court nonresident females more intensely than coresident females. Resident males also attempted to force copulation more frequently with nonresident females. These results indicate that males can operationally distinguish resident from nonresident females and suggest that males may recognize individual females. The selective forces underlying differential responses to resident and nonresident females presumably are related to differences in expected mating opportunities.