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Results | Food Web and its Function | Interesting Isotopic Studies

Interesting Isotopic Studies

ANIMAL STUDIES: Diet Discrimination, Tissue Differences and Diet Changes Over Time

Khutzeymateen bear tissue chart Bone collagen chart
Figure 1. Bears that eat a diet of just nuts and berries have tissue d15N and d13C values lower than those of bears that also eat salmon (which is higher up the food chain). View larger image.
Figure 2. Collagen preserved in modern and fossil bones records an organism’s relative diet. Carnivores have higher d15N and d13C values than herbivores. View larger image.

gerbil tissue chart gerbil tissue after diet change
Figure 3. Different tissues of gerbils have varying d13C values. Brain, muscle, and liver tissue best reflect the d13C signature of a gerbil’s diet. Note the large offset between diet and fat! Fat typically has lower d13C values than other tissues. View larger image.
Figure 4. When a gerbil’s diet is switched to food with a different d13C value, its tissues change over time to reflect this. This happens as carbon in the tissues is replaced. Some tissues show this change more rapidly than others. For example, liver tissue achieves the d13C value of the new diet in less than 80 days, whereas hair takes well over twice as long. View larger image.


  • Lyon, T.D.B. and Baxter, M.S., 1978. Stable carbon isotopes in human tissues. Nature, 273: 750-751.
  • O'Connell, T.C. and Hedges, R.E.M., 1999. Investigations into the effect of diet on modern human hair isotopic values. American Journal of Physical Anthropology, 108: 409-425.
  • Ostrom, P.H. and Fry, B., 1993. Sources and Cycling of Organic Matter within Modern and Prehistoric Food Webs. In: M.H. Engel and S.A. Macko (Editors), Organic Geochemistry. Plenum Press, New York, pp. 785-798.
  • Schwarcz, H.P., Melbye, J., Katzenberg, M.A. and Knyf, M., 1985. Stable isotopes in human skeletons of southern Ontario: Reconstructing paleodiet. Journal of Archaeological Science, 12: 187-206.
  • Tieszen, L.L., Boutton, T.W., Tesdahl, K.G. and Slade, N.A., 1983. Fractionation and turnover of stable carbon isotopes in animal tissues: Implications for d13C analysis of diet. Oecologia, 57: 32-37.
Using stable isotopes for research
Animal and Diet Studies
Human and Diet Studies
Results | Food Web and its Function | Interesting Isotopic Studies

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