Isotopic evidence of foraging ecology of Asian elephant (Elephas maximus) in South China during the Late Pleistocene

Abstract

Currently, knowledge of dietary preferences throughout the evolutionary history of the Asian elephant Elephas maximus is ambiguous due to the absence of quantified proxy from the Late Pleistocene. In this study, carbon and oxygen stable isotope analysis on the fossilized mammal teeth from the faunal assemblage recovered at Baxian Cave in Guangxi, South China was undertaken in order to reconstruct the dietary behavior and foraging ecology of Elephas maximus during the Late Pleistocene. The analyses of X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) on several samples showed that all teeth bioapatite was well-preserved. The isotopic data indicate that all the mammals relied entirely on C3-based foodstuff, revealing that C3 vegetation was dominant in this region. Two groups of the Asian elephants are observed in this study on the basis of isotopic difference. This isotopic variation among the Asian elephants evaluated in this study may suggest that they were mixed feeders. The dietary difference of the two groups observed may relate to elephant ages, seasonal variation and/or subspecies differences. In combination with previously published isotopic data, the dietary transition from substantial C4 plants to C3 plants of Elephas is discussed, indicating flexible dietary behavior throughout the evolution of the genus.