Consequences of environmentally induced variation in age and size at metamorphosis in Pacific treefrogs (Pseudacris regilla)

Many species with complex life cycles exhibit adaptive phenotypic plasticity in behavior and morphology during the larval stage.  While these strategies confer increased survival during the larval stage, they are associated with reduced size at metamorphosis and delayed metamorphosis.  Here, I test the effects of variation in size and age at metamorphosis on survival to and age at reproduction in cohorts of pacific treefrogs (Pseudacris regilla) metamorphosing from four ponds over three years.  Within cohorts, size at metamorphosis was positively correlated with survival and negatively correlated with age at reproduction.  Date of metamorphosis was negatively correlated with survival and positively correlated with age at first reproduction.  However, differences in survival and age structure between these populations could not be explained by differences in size at metamorphosis.  I discuss explanations for this discrepancy.