First Name:
Katherine
Last Name:
Pittman
Major Department:
Biology
Thesis Director:
Lynn Siefferman
Date of Thesis:
May 2009
Research with a population of socially monogamous Eastern bluebirds (Sialia sialis) breeding in Auburn, Alabama has demonstrated that the more colorful males feed offspring more often and fledge more offspring. However, this measurement of reproductive success does not account for the extra-pair young, which current research suggests comprise of 30% of the offspring in this population. these extra-pair young are fathered by a male that is not their mother’s social mate. In this study we used microsatellite DNA to assign paternity and test the hypothesis that male plumage coloration and personality type influence the likelihood of cuckoldry. We measured personality by recording the level of aggression towards simulated territorial intrusion and by quantifying male feeding rates to offspring. We confirmed previous findings that the brighter males in the population feed their offspring more often, and tend to be less aggressive. Through paternity analyses we demonstrate that bright males tend to be cuckolded less often than duller males. However, we found no correlation between aggression and cuckoldry which may suggest the most aggressive of the duller males are able to retain some paternity in their nests. Future research should assign paternity to all offspring in the population and test whether aggression predicts reproductive success.