Thursday, August 5, 2010

PS 72-66: Finding a perfect match: Female choice on male traits in eastern fence lizards, Sceloporus undulatus

Lindsey Noele Swierk and Tracy Langkilde. Penn State University


What makes a desirable mate? Understanding how animals select their mates can offer insight into which traits confer fitness benefits. However, reliably determining if female selection on male traits exists can be challenging. Especially in reptiles, female choice can be confounded by female selection of quality territory, or by the result of male contests. We designed an experiment using eastern fence lizards (Sceloporus undulatus) to uncover if females select their partners based on specific traits. We conducted 68 female choice trials in which one female lizard was presented with two males possessing identical territories. We quantified the time females spent associating with both males.


Although females preferred to associate with the larger male in their arena, if females were presented with males of identical size they nevertheless exhibited a clear preference for one male over the other. This suggests that additional male traits, such as genetic makeup, may be important in female choice. Future research is planned to examine factors that influence mate choice and mechanisms by which individuals may compensate for pairing with a suboptimal mate, using both fence lizards and wood frogs, Rana sylvatica, as model systems.