IDENTIFYING DIETARY AND MIGRATORY PATTERNS OF ILLINOIS MAMMUTHUS PRIMIGENIUS POPULATIONS USING ISOTOPE ANALYSIS OF CARBON, OXYGEN, AND STRONTIUM

The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboard throughout the Late Pleistocene (100-10 Ka). Although it is recognized that woolly mammoths coincided with and lived in a region heavily influenced by glacial ice sheets, little is known about their behavior with respect to activities like migration and dietary preferences in this environment. This study classifies and provides insight into the diet and mobility of Midwestern mammoths by analyzing stable isotopes of carbon, oxygen, and strontium preserved in the tooth enamel of these extinct elephantids. A woolly mammoth tooth from Moline, IL, was bulk-sampled and micromilled to extract the aforementioned isotopes from the base of the enamel. Dated to 16,410 ±110 BP (20,085-19,530 calBP), measured 𝛿¹³C (-12.6‰ to -11.1‰, PDB) values indicate that the terminal LGM landscape of western Illinois was dominated by C₃ vegetation, which is typical of a cooler climate. This cooler climate during the LGM is also reflected by the resulting high 𝛿¹⁸O values (-10.8‰ to -8.1‰, PDB). The ratios of ⁸⁷Sr/⁸⁶Sr isotopes retained in the tooth enamel were mapped using GIS onto a regional isoscape to determine the mobility of one mammoth across its lifetime. The mobility patterns were compared to seasonal and annual dietary shifts to better understand the underlying cause for migrations. Preliminary analyses of the ⁸⁷Sr/⁸⁶Sr values (0.7907 – 0.7156) suggest that there were regional population movements around the northern Mississippi River Valley. The data reveals the climate and landscape during the terminal Pleistocene in western Illinois and how woolly mammoths responded to it.