Doctor of Philosophy, The Ohio State University, 2020, Evolution, Ecology and Organismal Biology

Critical social interactions between animals such as courtship and competition over resources are mediated by communication signals, which have evolved via natural or sexual selection. Signals may have evolved to transmit information about senders, to affect receiver responses, or both. Birds have long served as focal organisms in studies of signaling, as many avian signals have undergone extensive elaboration. The role of avian signals in breeding behavior is also well studied, as many signals evolved specifically for use in this context. Additionally, birds exhibit several types of mating systems and the reliability of signal information may vary between mating systems. Among birds, some grouse species are distinguished by a promiscuous mating system which is often centered on leks. Although these species exhibit the classic lek-mating system, several questions related to signals transmitted during breeding behavior remain scantly researched. The research in this dissertation focuses on signals employed in the breeding behavior of the lek-mating lesser prairie-chicken (Tympanuchus pallidicinctus), a North American grouse (sub-family Tetraonidae). Males display two sets of bright, conspicuous color ornaments used in visual signaling and sound production during breeding behavior. I tested the hypotheses that these ornaments are honest signals of age, condition (Chapter 2), and parasite loads (Chapter 3). Additionally, I considered the effects of ornament size and color properties on male mating success and the performance of male duets which are unique to the lesser prairie-chicken relative to other grouse. In Chapter 4, I tested the hypothesis that females rely on the interpretation of multiple male signals when choosing mates, and in Chapter 5 I explored three non-mutually exclusive hypotheses related to male duets: 1) duets serve as an endurance contest, 2) duets serve as a mechanism to de-escalate or prevent violent interactions between males, and 3) duets (open full item for complete abstract)

Committee: Jacqueline Augustine PhD (Advisor); Robert Gates PhD (Committee Member); Ian Hamilton PhD (Committee Member); Christopher Tonra PhD (Committee Member) Subjects: Animals; Biology; Ecology; Evolution and Development; Zoology