Summary
Stable carbon isotope ratios in bone collagen have been used in a variety of dietary studies in modern and fossil animals, including humans. Inherent in the stable isotope technique is the assumption that the isotopic signature is a reflection of the diet and is persistent in collagen because this is a relatively inert protein. Carbon isotope analyses of bones from a southern Indian population of Asian elephant (Elephas maximus), a long-lived mammal that alternates seasonally between a predominantly C3 (browse) and C4 (grass) plant diet, showed two patterns that have important implications for dietary interpretation based on isotopic studies. Relative to the quantity of the two plant types consumed on average, the δ13C signal in collagen indicated that more carbon was incorporated from C3 plants, possibly due to their higher protein contribution. There was a much greater variance in δ13C values of collagen in sub-adult (range -10.5‰ to-22.7‰, variance=14.51) compared to adult animals (range -16.0‰ to -20.3‰, variance=1.85) pointing to high collagen turnover rates and non-persistent isotopic signatures in younger, growing animals. It thus seems important to correct for any significant relative differences in nutritive value of food types and also consider the age of an animal before drawing definite conclusions about its diet from isotope ratios.
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References
Altmann J (1974) Observational study of behaviour: sampling methods. Behaviour 49: 227–267
Boutton TW, Wong WW, Hachey DL, Lee LS, Cabrera MP, Klein PD (1983) Comparison of quartz and pyrex tubes for combustion of organic samples for stable carbon isotope analysis. Anal Chem 55: 1832–1833
Chisholm BS, Nelson DE, Schwarcz HP (1982) Stable-carbon isotope ratios as a measure of marine versus terrestrial protein in ancient diets. Science 216: 1131–1132
Craig H (1957) Isotopic standards for carbon and oxygen and correction factors for mass spectrometric analysis of carbon dioxide. Geochim Cosmochim Acta 12: 133–149
DeNiro M, Epstein S (1978a) Carbon isotopic evidence for different feeding patterns in two hyrax species occupying the same habitat. Science 201: 906–908
DeNiro M, Epstein S (1978b) Influence of diet on the distribution of carbon isotopes in animals. Geochim Cosmochim Acta 42: 495–506
Douglas-Hamilton I, Douglas-Hamilton O (1975) Among the elephants. Collins and Harvill, London
Laws RM, Parker ISC, Johnstone RCB (1975) Elephants and their habitats. Clarendon Press, Oxford
Lewin R (1983) Isotopes give clues to past diets. Science 220: 1369
Libby WF, Berger R, Mead J, Alexander G, Ross J (1964) Replacement rates for human tissue from atmospheric radiocarbon. Science 146: 1170–1172
Minson DJ, Ludlow MM, Troughton JH (1975) Differences in natural carbon isotope ratios of milk and hair from cattle grazing tropical and temperate pastures. Nature 256: 602
Moss C (1988) Elephant memories. William Morrow, New York
Ramsay MA, Hobson KA (1991) Polar bears make little use of terrestrial food webs: evidence from stable-carbon isotope analysis. Oecologia 86: 598–600
Roth VL, Shoshani J (1988) Dental identification and age determination inElephas maximus. J Zool London 214: 567–588
Rundel PW, Ehleringer JR, Nagy KA (eds) (1989) Stable isotopes in ecological research. Springer-Verlag, Berlin Heidelberg New York
Sealy JC, van der Merwe NJ (1985) Isotope assessment of Holocene human diets in the southwestern Cape, South Africa, Nature 315: 138–140
Smith BN, Epstein S (1971) Two categories of13C/12C ratios for higher plants. Plant Physiol 47: 380–384
Stenhouse MJ, Baxter MS (1977) Bomb14C as a biological tracer. Nature 267: 828–832
Sukumar R (1989) The Asian elephant: ecology and management. Cambridge: Cambridge University Press
Sukumar R, Bhattacharya SK, Krishnamurthy RV (1987) Carbon isotopic evidence for different feeding patterns in an Asian elephant population. Curr Sci (Bangalore) 56: 11–14
Sukumar R, Joshi NV, Krishnamurthy V (1988) Growth in the Asian elephant. Proc Indian Acad Sci (Anim Sci) 97: 561–571
Tauber H (1981)13C evidence for dietary habits of prehistoric man in Denmark. Nature 292: 332–333
Tieszen LL (1978) Carbon isotope fractionation in biological material. Nature 276: 97–98
Tieszen LL, Boutton TW, Tsedahl KG, Slade NA (1983) Fractionation and turnover of stable carbon isotopes in animal tissues: Implications for δ13C analysis of diet. Oecologia 57: 32–37
Tieszen LL, Boutton TW, Ottichilo WK, Nelson DE, Brandt DH (1989) An assessment of long-term food habits of Tsavo elephants based on stable carbon and nitrogen isotope ratios of bone collagen. Afr J Ecol 27: 219–226
van der Merwe NJ, Vogel JC (1978)13C content of human collagen as a measure of prehistoric diet in woodland North America. Nature 276: 815–816
Woessner JF Jr (1968) Biological mechanisms of collagen resorption. In: Gould BS (ed) Treatise on collagen Vol 2. Academic Press, London, pp 253–329
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Sukumar, R., Ramesh, R. Stable carbon isotope ratios in Asian elephant collagen: implications for dietary studies. Oecologia 91, 536–539 (1992). https://doi.org/10.1007/BF00650328
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DOI: https://doi.org/10.1007/BF00650328