SEARCH PATH OF A FOSSORIAL HERBIVORE, GEOMYS-BURSARIUS, FORAGING IN STRUCTURALLY COMPLEX-PLANT COMMUNITIES

Examines the influence of habitat patchiness and unpalatable plants on the search path of plains pocket gopher, evaluating how individual animals explored (by tunnel excavation) enclosures free of plants except for ≥1 dense patches of a palatable plant (Daucus carota), a dense patch of an unpalatable species (Pastinaca sativa) containing a few palatable plants (D. carota), or a relatively sparse mixture of palatable (D. carota) and unpalatable (Raphanus sativus) species. Only 2 of 8 individuals showed the predicted pattern of concentrating search effort in patches of palatable plants. Maintenance of relatively high levels of effort in less profitable sites may reflect the security afforded food resources by the solitary social system and fossorial lifestyle of G. bursarius. Unpalatable plants repelled animals under some conditions, but search paths in the sparsely planted mixed-species treatment suggest animals can use visual or other cues to orient excavations. Evidence supporting area-restricted search was weak. -from Author