Stable carbon isotope variability of bone collagen and hair within a modern population of red kangaroos (Macropus rufus) in south western Queensland: some implications for palaeoecological research

Full text: Before any palaeo-reconstruction work can be attempted using stable isotope analysis of macropod remains it will be necessary to determine the nature of natural variability within contemporary populations. This research indicates that δ13C of bone collagen is strongly related to age. Furthermore, bone collagen δ13C not at equilibrium with dietary δ13C, as indicated by analysis of hair, until animals are several years old. These preliminary data suggest that in younger macropods most carbon in bone collagen has been derived via the mother's milk which may have undergone fractionation. These findings have significant implications for any palaeoecological research using bone or tooth. Teeth of macropods erupt from the rear of the jaw and move forward in molar progression. Since the rate of eruption is variable, and many of the forward molars are well formed while the joey is still at the pouch, teeth formed early in the life of a macropod may be isotopically distinct from those that develop later. This hypothesis is currently under investigation