Nutritional ecology of yellow‐bellied marmots in the White Mountains of California

This study examined the basis of diet preference in a mammalian hibernator, the yellow‐bellied marmot Marmota flaviventris , in the White Mountains of California. Preference indices calculated from dietary data and food plant availability in the habitat indicated that forb species were preferred over graminoids, particularly in the spring and early summer. Chemical analysis of food plant species suggested that marmots preferred forbs over graminoids because of their lower fiber (cellulose) content and higher concentrations of phosphorus, sodium and possibly protein. Inclusion of graminoids in the diets was probably due to their greater availability in the habitat coupled with the need to maximize the rate of nutrient intake during the short (4–5 month) active season. Seasonal changes in diet composition were noted which may reflect, in part, temporal changes in nutrient demands.