Does courtship behavior predict parentage in Collared Lizards? Influence of male social status and habitat structure

Incorporating microsatellite techniques to determine parentage is a powerful addition to behavioral mating system studies in wild animals. Nonetheless, in some tetrapod taxa such as lizards, there are relatively few direct comparisons of individual reproductive success measured genetically versus estimates based on behavioral interactions, especially in species where males and females do not maintain prolonged social contact. We combined observations of behavior with microsatellite analysis of parentage over ten seasons in male Collared Lizards, (Crotaphytus collaris), to test the extent to which the proportion of each female's total courtship interactions with different males predicted the proportion of total offspring sired by those males (proportion of paternity). Territorial males (T-males) court females frequently. Non-territorial (NT) males on the other hand behave stealthily. This allows them to court females, albeit less frequently, while limiting attacks by T-males. Both T- and NT-males occupied habitats that varied in structural complexity which might influence which males court and sire offspring with individual females, therefore we included habitat type (simple vs. complex) and male social tactic as possible predictors in our test. Proportion of courtship by NT-males did not predict their proportion of paternity in either habitat type. Courtship by T-males was a strong predictor of paternity in simple habitats but not complex habitats. Our findings support the hypothesis that courtship is a more accurate predictor of T-male mating success in simple habitats, which is consistent with previous findings suggesting that reduced area and topographical heterogeneity, especially the absence of subsurface crevices in simpler habitats, makes it more economical for T-males to prevent surreptitious mating by NT-males. Our study, therefore, highlights the importance of considering possible effects of alternative social tactics and variation in environmental conditions when testing the accuracy of behaviorally based estimates of breeding relationships, especially in polygamous species with multiple paternity.

Automated summary

Incorporating microsatellite techniques to determine parentage in wild animal mating system studies is powerful. The study found that non-territorial males behave differently from territorial males, and in simple habitats, courtship behavior by territorial males is more likely to predict paternity, emphasizing the importance of considering different social tactics and environmental conditions when testing the accuracy of behaviorally based estimates of breeding relationships.