Diet Selection on Depletable Resources

Publisher Website
Google Scholar
Abstract
We tested a number of patch use and diet choice strategies using natural populations of kangaroo rats, Dipodomys merriami. Patch use strategies included leaving patches: 1) at a fixed quitting harvest rate, 2) after a fixed search time, and 3) after a fixed amount of harvest. The diet choice strategies included: 1) expanding specialist, 2) micropatch partitioning, and 3) resource-specific encounter rates. The predictions of these strategies were couched in terms of forager use of patches containing two resource types and subject to resource depletion. The giving up densities of kangaroo rats in manipulated resource patches provided the measure of utilization. With respect to patch use, the kangaroo rats use a fixed quitting harvest rate strategy. With respect to diet choice, they incorporate elements of all three diet strategies. This latter result is reasonable given: 1) the biology of kangaroo rats, 2) the characteristics of the resource patches, and 3) that the diet choice strategies are not mutually exclusive.