Optimal Reproductive Allocation in Female Dusky Salamanders: A Quantitative Test

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Abstract
Analyzing a model of reproduction in Desmognathus ochrophaeus using optimal-control theory suggests that female salamanders can maximize their fecundity by using one of two allocation schemes. Fecundity will be maximized either by allocating food resources to reproduction for the entire period before egg laying or, if enough food is available, by growing first and then switching to egg production later in the season. Egg mortality is minimized if the female provides maternal care at the maximum level throughout brooding. Numerical analyses using data from studies of the energetics, behavior, and demography of D. ochrophaeus indicate that the food intake of sexually mature females probably is not sufficiently high to allow growth before egg production. Furthermore, reproductive success depends on the relationship between female size, efficacy of maternal care, and predation risk. Egg clutches of small females may be subject to high mortality in spite of maternal care. Thus, energetics, behavior, and the consequences of body size may have resulted in the evolution of delayed maturity in this species.