Spatial and behavioral foraging patterns and diet selectivity in the social yellow bellied marmot

Abstract

Two colonies of yellow-bellied marmots (Marmota flaviventris) at an elevation of 2900 min Colorado were studied to elucidate the role of various behavioral and ecological factors as determinants of spatial foraging patterns. The locations of known individuals were periodically recorded. These locality data were plotted as three-dimensional block diagrams, the peak heights representing the frequency of observation. Predation risk and vegetation distribution influenced the location of foraging areas, but kinship was the most important factor in the determination of the amount of foraging area overlap between individual marmots. Overlap tended to be greatest among close kin, but this was modified by individual behavioral characteristics, reproductive state, the existence of separate burrow systems within a colony, and the age of the animal. Mothers and juveniles, and littermates as young and resident yearlings, had nearly identical foraging areas.