8 - Production: Growth and reproduction

Summary

Production is the last component of the balanced growth equation that we can examine in depth and probably the most important. Production determines the amount of exploitation by man or natural predators that a population can withstand, the capacity of a population to recover from depredation, and its ability to resist control. Conversely, production defines the role of an animal population as a continuing resource for other members of its community, and, therefore, it determines much of the population's role in directing mass and energy to other parts of the community. Finally, the relationships of production to ingestion and respiration describe efficiencies of resource use around which animal communities must be organized and upon which human utilization of both wild and domestic stocks depends (Ames 1980).

The primary goal of this chapter is an equation or set of equations that predicts average rates of total production from animal size. These equations are essential for the allometric definition of the balanced growth equation, which is an underlying theme of this book, and for further analysis of the implications of body size in animal ecology. However, relations that predict average individual rates of production are rare and often imprecise. Were this chapter to limit itself to predicting individual production rates, it would seriously underestimate our knowledge of the scaling of the production process. Body size–production relations for use in the balanced growth equation will be treated at the end of the chapter.