Influence of Artificial Food on Stable Carbon and Nitrogen Isotope Composition of Plateau Pikas

To better understand stable isotope enrichment and metabolism of small \nmammals and to provide alternative for their dietary information \nanalysis,a controlled feeding experiment was conducted on plateau pikas \n(Ochotona curzoniae ) with mixture of flours of corn (C4 \nplant),millet (C4 plant) and mung bean (C3 plant).Muscles of back legs \nwere collected from plateau pikas for stable isotope analyses after 40 \ndays' artificial feeding.The results demonstrated that stable carbon \nand nitrogen isotopes showed great variations after introduction of \nartificial food.Stable carbon isotope ratios of treatment groups became \nless negative compared with the control [(-19.05±0.09)] to \n(-24.66±0.42)]% and showed great differences \n(t=-31.528,df=6,P=0.000).Stable nitrogen isotope ratios of treatment \ngroups were a little bit positive compared with the control \n[(3.61±0.32)] to (3.28±0.13)]% \n(t=1.427,df=7,P=0.197).Fractionations of stable carbon and nitrogen \nisotopes between plateau pikas' muscles and their diets were 4.73] and \n2.79] respectively.Introduction of C4 food had strong effect on stable \nisotope metabolism (especially for stable nitrogen isotope) of plateau \npikas.Turnover rate of stable carbon and nitrogen isotopes for plateau \npikas might be much more than forty days as respected.