Abstract

We examined trade-offs between current reproduction and future reproductive potential in a terrestrial salamander (Plethodon cinereus) in outdoor enclosures. We raised females that differed in brooding status under manipulations of food level and tail condition in two years (1993 and 1994), and measured the effects of our treatments on current reproductive success (egg survival) and indicators of future reproductive potential (female growth and production of ova). Current reproductive success depended strongly on clutch size but not resource availability. Brood abandonment was higher among females with small clutches. Both brooding status and tail condition affected future reproductive potential. Brooding females gained less mass and produced fewer new ova than nonbrooders. Tail loss resulted in increased tail regeneration but decreased production of new ova. These strong main effects were consistent between years, despite differences in experimental protocol and limited sample sizes. Food levels affected female growth only in interaction with brooding status, and these effects differed between years. Gain in mass was affected by this interaction more strongly in 1993 than in 1994, and tail regeneration was only affected in 1994. Understanding costs of reproduction in natural populations will require understanding how the condition of both the organism and its environment influence energy allocation to current reproduction and different components of future reproductive potential.