关键词: 植食性小哺乳类, 营养生态学, 高原鼠兔, 食物选择, 食物质量

Abstract: This paper reported the food pattern，food preference index and natritional componant of food itemsJ and analysed the relation between the food quality and the food selection．PIateau pikas mostly ate dicotyledon leaves．Comparison of diet composition with forage availability indicated the food selective degree on each food item for plateau pikas．PIateau pikas strongly preferred Elymus nutans，Oxytropis ochrocephala and Potentilla nivea, Contents of nutrient component in the three food items were changed markly monthly．Wefound positive correlations between dietary percents of food item sand those for water，crude protein，sodium (Na)and phosnhorus(P)contents，and negative correlations between dietary percents and those for fat，fibrel potassium (K)，calcium (Ca)and magnesium (M g) contents．Multiple regressive techniques revealed that only the relationships with dietary percents and phosphorus (P) content remained singnificant wheneffects of other nutrients were removed．Those correlations and regressions between those nutrients and dietary percents were diffcrrents(Table 5 and Table 6)．Those results above support to the hypothesis：the forage availability and found quality decide food selection．

Key words: Herbivorous small mammalsI Nutritional ecology, Plateau pika(Ocherulae), Food selection, Food quality