Oral Presentations and Performances: Session II
Project Type
Presentation
Faculty Mentor’s Full Name
Douglas Emlen
Faculty Mentor’s Department
Division of Biological Sciences
Additional Mentor
Sophia Fitzgerald sophia.fitzgerald@umconnect.umt.edu
Abstract / Artist's Statement
A Night in the Life of a Female Japanese Rhinoceros Beetle
During the height of the mating season, Japanese rhinoceros beetle (Trypoxylus dichotomus) males aggregate on trees to fight against rivals over access to females. Males in this species are very well studied for their charismatic, large horns that constitute up to 30% of their body weight. However, winning fights is not enough to guarantee matings. Males must still perform complex courtship songs on the backs of females, and surprisingly, females ultimately choose only one male to mate with. Females may evaluate male quality via these songs, which serve as auditory and tactile signals. Nevertheless, female Japanese rhinoceros beetles are understudied compared to males. To assess female experience and influence we conducted a comprehensive field study following marked males and females over the course of the breeding season. For any given mating event, we quantified how many unique males contacted and courted each female, which males successfully copulated, and what sequence of events led to a mating event. This detailed study also allows us to disentangle how female choice and male competition relate in this species. By describing the course of events that unfold over a night, we hope to highlight the importance of female choice and elaborate male courtship songs in a species with extreme animal weapons.
Category
Life Sciences
A Night in the Life of a Female Japanese Rhinoceros Beetle
UC 327
A Night in the Life of a Female Japanese Rhinoceros Beetle
During the height of the mating season, Japanese rhinoceros beetle (Trypoxylus dichotomus) males aggregate on trees to fight against rivals over access to females. Males in this species are very well studied for their charismatic, large horns that constitute up to 30% of their body weight. However, winning fights is not enough to guarantee matings. Males must still perform complex courtship songs on the backs of females, and surprisingly, females ultimately choose only one male to mate with. Females may evaluate male quality via these songs, which serve as auditory and tactile signals. Nevertheless, female Japanese rhinoceros beetles are understudied compared to males. To assess female experience and influence we conducted a comprehensive field study following marked males and females over the course of the breeding season. For any given mating event, we quantified how many unique males contacted and courted each female, which males successfully copulated, and what sequence of events led to a mating event. This detailed study also allows us to disentangle how female choice and male competition relate in this species. By describing the course of events that unfold over a night, we hope to highlight the importance of female choice and elaborate male courtship songs in a species with extreme animal weapons.