Optimal Offspring Provisioning when Resources are not Predictable

I begin with two basic premises: first, that organisms frequently must base offspring allocation decisions on expected levels of resource availability, and second, that allocated resources are at least partially nonrecoverable. Given this, how many offspring should an organism begin to provision? Here, I develop an analytical model to address this question. In this model I make offspring fitness a function of the integral of all possible resource states, multiplied by the probability density function for parental resources. Parental fitness is the product of offspring fitness and the number of offspring. I solve this basic model numerically and find that the optimum offspring number for iteroparous organisms is not strongly affected by variance. In contrast, semelparous organisms maximize their expected reproductive success by initiating fewer offspring as variance increases. I use my results to provide a theoretical explanation for seasonal seed size decline in plants.