Using the Pronghorn to Test the Strength of Sexual Selection
Sexual selection, or selection caused by competition over mates, is a major driving force of evolution. To understand sexual selection in the wild, detailed knowledge of individual identities and mating success is required but is rarely available. Recently a model based on the distribution of sexually receptive females in space and time was proposed as a proxy to estimate the strength of sexual selection in the absence of detailed population information (Shuster and Wade 2003). For the first time, the validity of this model will be tested using the population of pronghorn (Antilocapra americana) found on the National Bison Range, Montana. Behavioral observations will be used to calculate the intensity of sexual selection based on the Shuster and Wade (2003) model. These results will be compared to the intensity of sexual selection calculated using genetic paternity analyses. If the model is valid, sexual selection should be a strong force when receptive females are clustered in space and a weak force when they are clustered in time. The estimate of the intensity of sexual selection determined using behavioral data should also correlate with that found using the genetic analyses. As broader impacts, the results of this study will be pertinent to a variety of fields including animal behavior, evolution, and genetics. The data will provide information on basic population parameters to the U.S. Fish and Wildlife Service for use in management of pronghorn. This project involves collaboration between two colleges at the University of Idaho, and will lead to the training of one female Ph.D. student and approximately 12 undergraduate students. Information from this project will not only be presented at scientific conferences, but also to an upper-division biology major Animal Behavior course, to biology students at St. Maries High School in rural St. Maries, Idaho, and to visitors at the National Bison Range.
