Date of Graduation
Master of Science in Biology (MS)
Erica L. Westerman
Marlis R. Douglas
Second Committee Member
Third Committee Member
Neelendra K. Joshi
Two key components of mate choice research focus on: 1) who an organism mates with, which may be influenced by any number of factors from sexual ornamentation to male-male competition; and, 2) when an organism courts, be it daily, monthly, or seasonally. Both aspects are especially important for gregarious species as mistakes in either can incur high costs to overall fitness. My research focuses on using butterflies to explore kin recognition from the larval stage and its possible impacts on adult mate choice and if courtship is circadian in Heliconius hewitsoni. My first experiment concerned kin recognition. When inbred, Bicyclus anynana are known to suffer from inbreeding depression, however populations can recover lost fitness within just a few generations when allowed to mate freely. It has been shown that B. anynana can recognize and choose against inbred individuals, however it is unknown whether they can detect siblings. I demonstrated that larval rearing condition (isolated or gregarious) did not influence adult mate choice in that female B. anynana did not innately detect or learn to detect and avoid sibling males during mate selection. Thus, in B. anynana, kin recognition may not be important to reproductive fitness. Through analysis of recorded behavior, I also showed that male harassment did not influence female mate choice. In my second experiment I examined circadian rhythms, specifically regarding courtship. I demonstrated that H. hewitsoni exhibits circadian rhythms, including a period of peak courtship around noon, and that some behaviors are sexually dimorphic in these butterflies. Recorded peak activity closely matches diurnal behavior in H. hewitsoni’s primary food source, which may influence overall behavior patterns in this species. My findings broaden our understanding of the mechanisms behind mate choice and provide valuable information for future research in these two systems, including the importance of female choice versus male harassment and sexual dimorphism in behavior. With my research I have improved our overall understanding of kin recognition and circadian rhythms to address the “who” and “when” of mate choice.
Robertson, Deonna Nicole, "A Tale of Two Butterflies: The Effect of Larval Social Environment and Circadian Rhythms on Mating Behavior in Bicyclus anynana and Heliconius hewitsoni" (2018). Theses and Dissertations. 3093.