Possible Female Preference in Hatchling Collared Lizards, Crotaphytus collaris: Precocial Sexual Selection

Abstract

All species have a varying preference for phenotypic traits for sexual selection. Sexual selection can be based on the specie’s sexual dimorphism such as their color, size, and structure.  A lot of the extraordinary morphological and behavioral diversity in the animal kingdom has come up through sexual selection. The species in particular that we are researching over is the Crotaphytus collaris along with their choices for sexual selection. Males of this species show off vivid orange bars horizontally across their backs while the females stay drab. And the true purpose of these orange bars is unknown though they bring up questions. These lizards also pair bond so they will have a mate when they come out of hibernation for the mating season. Because of this, females get to choose which males they want to mate and pair bond with based on their preference of phenotypic traits of the males.  Much of this helped us bring up the question that we are asking which is “Do either female collared lizard hatchlings and/or yearlings prefer males with bright orange bars over the males that are drab?” Understanding this question will help with understanding the questions behind the mystery of the oranges bars. I hypothesize that females would have a greater preference towards the Hatchling orange barred males which will be a delayed benefit towards fitness. I hypothesized this because if the females preferred males with orange bars then there would be less of an availability of mating with males making for a smaller amount of clutches leading to a delayed benefit towards the lizard’s fitness. In order to try to prove my hypothesis for this project we will go out to our site at sooner lake; we have sites on both the dam known as SL1 and in an area along the shoreline known as SL2. By use of the technique known as noosing we will capture about 20+ of both males and females ranging from hatchlings to yearlings so as for a larger group of test subject.  The lizards will be transported back to our lab at the Stillwater campus. We will use three tanks for the lizards during trials; two tanks will be set up identical to each other side by side, horizontally, but have the view of both tanks side blocked from sight so the males will not be able to see each other. We will observe the decisions of the females over a period of one to two hours to see which male she prefers. Her preference will be determined based on which of the two males she will stay closest to or further from the longest. I expect that the females will choose the females will choose the males with these orange bars over their drab counterparts. Though I do expect that there is a possibility that my hypothesis is wrong and the females might choose the drab males over the vivid males or they may choose neither.