On the Missed Opportunity Cost, Gud, and Estimating Environmental Quality

Abstract

The missed opportunity cost (MOC), i.e., all foregone alternatives while foraging in a patch, is an important aspect of the cost-benefit analysis of foraging patch use. When making between-environment comparisons it will often be the most important factor influencing behavior, but it has received less interest than other foraging costs. In this paper, we focus on differences between individuals living in different territories or home ranges and how giving-up densities of food (GUD) should reflect between-environment differences in habitat suitability. We then investigate the extent to which such differences depend on effects mediated through the cost of predation or MOC. We model different scenarios for individuals in different environments and review literature on empirical studies that investigate such scenarios. The modeling results show that all three components of the MOC (survival rate, marginal value of energy, and marginal value of time) depend on average resource availability in the environment. This makes MOC, and thereby GUD, increase strongly with food availability. MOC increases only weakly with safety from predation, and moderately as travel distance between food patches declines. Also the cost of predation increases with richness of the environment, and notably it differs more between safe and risky patches in rich environments. These results are reflected in the GUDs, which are higher in environments with high food availability and short travel distances. In contrast, GUDs vary only marginally between safe and risky environments.