Peucaea aestivalis

Animals face both natural and sexual selection pressures, and at times, these pressures conflict with one another. This results in a tradeoff between sexual and natural selection. In my thesis, I examine aspects of Bachman’s sparrows’ behavior and morphology in relation to weather conditions in light of these two conflicting pressures.
Large bill size is selected for by the natural selection pressures of thermoregulation. Smaller bills are selected for by the sexual selection pressures of song quality. Both thermoregulation and song are important behaviors/processes that have fitness implications. By looking at bill size in relation to thermoregulatory ability and song quality I examined the tradeoff between these two selection pressures acting on the bill of Bachman’s sparrows

Behavioral ecology is an integrative field that span many different topics from genes and physiology to ecology and evolutionary biology. In this dissertation, I studied territoriality, behavioral plasticity and syndromes, song learning, and natal dispersal in the Bachman’s sparrow (Peucaea aestivalis), an imperiled songbird that is understudied in many aspects of its behavior. In chapter one, I provide a background of behavioral ecology, the topics covered in this dissertation, and the Bachman’s sparrow. In chapter two, I determine if the ideal despotic distribution applies to Bachman’s sparrows. In chapter three, I examine whether two common personality traits, aggressiveness and boldness, are consistent over time and form a behavioral syndrome, or if they change in relation to environmental variables. My last chapter infers song learning and natal dispersal strategies in Bachman’s sparrows from examining patterns song-type sharing over geographic distance.