Terminal reproductive investment in male Eastern Gray Treefrogs (Dryophytes versicolor, Anura: Hylidae) is a marathon not a sprint

Abstract

The idea that greater investment in current reproductive events reduces future survival is fundamental to our understanding of life history evolution. The terminal investment hypothesis proposes that individuals with limited future reproductive opportunities will invest more time and energy into the current reproductive event. We tested this hypothesis in male Eastern Gray Treefrogs (Dryophytes versicolor LeConte 1825) predicting that larger, older males will spend more time at the breeding pond and lose a greater percentage of their body mass over the entirety of the breeding season. We found a positive correlation between male size and the number of nights males attended the breeding pond; males that attended the pond more often also lost more weight over the breeding season. Lastly, larger older males extended their breeding season by remaining at the pond later in the season, rather than arriving earlier. Moreover, males that invested more in reproduction were less likely to be recaptured the following year. These results suggest that older males invest more in reproduction than younger males and pay a cost in terms of future survival, which is consistent with the terminal investment hypothesis.