Spatiotemporal reproductive strategies in the fire salamander: A model and empirical test

Although density-dependent processes and the risk of pool desiccation dominate temporary pool ecology literature, the spreading of larvae across pools and time as a strategy for managing these central stress factors has not been rigorously addressed as an adaptive mechanism. We develop a state-dependent oviposition habitat selection model predicting that females of the endangered fire salamander, Salamandra infraimmaculata, will split their larval load temporally during the rainy season and across multiple pools and will adjust the number of larvae deposited according to pool quality. These strategies are predicted to reduce the negative effects of larval density-dependence and limited habitat duration. We tested the qualitative predictions of the model in an outdoor experiment. Consistent with our predictions, gravid females, when allowed to choose deposition sites among pools of different depths, spread their larvae both spatially and temporally and deposited more larvae into deeper pools. This study offers a novel theoretical and experimental framework for studying the evolution of reproductive strategies in ephemeral systems.