James Brown,, James Gillooly, Joseph Jun, John Pepper, Van Savage

Paper #: 03-02-005

The aggregation of individuals into colonies raises important questions about scaling of structure and function. We model the metabolic benefits and costs of two-dimensional, fractal-like foraging trails, such as those used by ant colonies. The total area foraged by the colony and, consequently, the resource flow to the nest and rate of colony metabolism, increase non-linearly with the number of foragers (F) as F 2/3. Since the cost of foraging increases linearly with F, the model predicts an optimal number of foragers and, therefore, the total foraging area that maximizes colony fitness or energy allocation to reproduction. The scaling of foraging may influence the evolution of coloniality.