This study was conducted to determinate carbon and nitrogen isotope fractionation in Bolivian and Chilean alpaca, llama and guanaco, hair, breath, plasma and feces. We also wanted to determine forage selection for these camelids using stable isotope technology. From the data, niche feeding and diet selection habits will determinate based on fecal composition. Bolivian sites were located near the high snow Altiplano Mountains at Tomarapi, Sajama, and at the Technical University Oruro's research center at Condoriri, Bolivia. Chilean samples were collected at INIA's (Instituto Nacional de Investigacion Agropecuaria) Kampenaike Research Station, Punta Arenas, Chile. Bolivian alpacas and llamas were 3 to 5 years of age from producer herds and the Oruro University's camelid herd. Chilean animals were selected from INIA- Kampenaike's camelid herd. The alpacas, llamas and guanacos were selected based on heath status: no conformation defects, illness, genetic abnormalities or apparent nutrition problems. Samples were taken of fiber, feces, and blood from alpacas, llamas, and guanacos. Forage samples from pastures and grazing areas were taken. Forage species that were collected came from the asteraceae, berberidaceae, gramineae, caryophyllaceae, leguminoseae, plantaginaceae, gentianiaceae and the chenopodaceae families and ranged from -15.5‰ to -33.9‰ δ13C and -3.0‰ to 6.4‰ δ15N. Isotope values for feces and fiber were similar for the two Bolivian sites, but the Chilean values were significantly more depleted. This was attributed to the forage isotopic values being significantly more depleted than those found in Bolivia. Forage selection, based on fecal and forage isotopic signatures supported the observation that alpacas, llamas and guanacos eat different forages. This is dependent on forage source and time of year (dry versus wet season). Stable isotope technology will be a useful tool in determining forage selection and species competition or interactions in South American Camelids.



College and Department

Life Sciences; Plant and Wildlife Sciences



Date Submitted


Document Type





Llama, Alpaca, Guanaco, Vicuna