The Himalayan marmot (Marmota himalayana) occurs throughout the Himalayan alpine mountain ecosystem.We examined the characteristics of Himalayan marmot habitat,diet and macronutrient consumption in the upper Mustang region of Nepal.Marmots inhabitwarmer valleys close to water sources in areas between 3200 m and 5100 m above sea level.Soil pH,organic matter,and organic carbon were not different in habitat occupied by marmots compared to areas where marmots were absent; however,phosphorus (P2O5) levels were higher and potash (K2O) levels lower in marmot burrow habitat.Seventeen species of plants,including Primula spp,Potentilla fruticosa,Kobresia pygmaea,Anaphalis contorta,Lonicera spinosa and Corex spp were recorded in marmot scats over three seasons (summer,autumn and spring) .Analysis showed a positive correlation between the total macronutrient content (dry matter protein + carbohydrate + fat) of plants and their occurrence in the diet.Analysis of the macronutrient balance of marmot diets indicated marmots consumed more plants high in protein pre-hibernation,and plants higher in non-protein macronutrients post-hibernation.Furthermore,the frequency of plants in the diet did not reflect their abundance in the environment,suggesting active selection of plants high in total macronutrient concentration.