| dc.description.abstract | The complex courtship signaling of three of the four species groups of the Sophophora subgenus (e.g., melanogaster, obscura, and willistoni) has been studied. In this dissertation, I examined the complex courtship signaling of the fourth species group, saltans, for the first time. In the first chapter, I assessed through what modalities courtship signals were communicated in Drosophila saltans (sensu stricto). No single modality ablation eliminated mating, and all ablations affected mating, thus courtship was multimodal. In the second chapter, I examined if the role of two modalities (i.e., vision and audition) during mating were correlated in nine species of the saltans species group. In particular, I investigated if the two modalities were assessed in an integrated manner (i.e., positively correlated), or if there was a tradeoff between the role of two modalities (i.e., negatively correlated). The role of vision and audition varied from playing no role to being necessary for mating success and were not correlated when considering independent contrasts. In Chapter Two, I also described the auditory courtship signal of each species of the group and found variation in song production with one species producing an elaborated song element and two species producing reduced songs. Furthermore, song production (reduced or elaborated) was not associated with the role of audition in mating success. In the third chapter, I examined if the two song types (i.e., pulse and beep) in the elaborated song of D. sturtevanti communicated one or multiple messages and if the messages were unique or redundant. The song of D. sturtevanti conveyed multiple redundant messages. In summary, I found that courtship signaling was complex by being multimodal in D. saltans (sensu stricto) and containing both multiple, and redundant messages in the auditory modality of D. sturtevanti. Also, I found that apparent signal complexity of song was not associated with the role of song during courtship. | |
