A Mechanistic Two-Stage Mating Model for Alternative Reproductive Tactics in Eurycea wilderae

Alternative reproductive tactics (ARTs) are discrete reproductive strategies used by individuals of the same sex. The Blue Ridge two-lined salamander, Eurycea wilderae, shows a sequential ARTs system in which males are categorized as Searchers and Guarders. Unlike in classic ARTs systems, these two tactics do not appear to compete directly for the same mating opportunity or resources. During the early breeding season, Searcher males are active on land and court females in the fall; later, females enter streams and may mate again with Guarder males near aquatic nesting sites before spring egg laying. Maintaining a stable polymorphism in nature is theoretically challenging. Therefore, in this project, we develop a discrete-time frequency model to explore what ecological and reproductive conditions can maintain both Searcher and Guarder tactics as a stable polymorphism.