CHICKEN AND EGG: TESTING THE CARBON ISOTOPIC EFFECTS OF CARNIVORY AND HERBIVORY

摘要

In bone, the spacing between delta C-13 in collagen and bioapatite carbonate is greater in herbivores than carnivores, with implications for understanding animal dietary ecology from surviving hard tissues. Two explanations have been proposed: varying diet composition or differences in physiology between herbivores and carnivores. We measured the isotopic effects of carnivorous and herbivorous diets on a single species, to test the effect of diet composition alone. Protein delta C-13 and delta N-15 and carbonate delta C-13 were measured on egg and bone from hens on different diets. Herbivorous hens had a +14.3% spacing between egg albumen and shell delta C-13, compared to +12.4% for omnivorous hens, and +11.5% for carnivorous hens. The bioapatite-collagen. Delta C-13 spacing was measured as +6.2% for herbivorous hens, and calculated as +4.3% for omnivorous hens, and +3.4% for carnivorous hens-similar to observed mammalian herbivore and carnivore bioapatite-collagen. Delta C-13 differences. We conclude that a shift in diet composition from herbivory to carnivory in a single species does alter the bioapatite-collagen carbon isotopic spacing. Our data strongly suggest that this results from differences in the. Delta C-13(bioapatite) (diet) spacing, and not that of. Delta C-13(collagen) (diet).