COMPLEMENTARY APPROACHES TO INFERRING LATE PLEISTOCENE PROBOSCIDEAN NICHES: UNITING GEOCHEMICAL AND CONSERVATION TOOLS

Studies of the end Pleistocene megafauna extinction provide an opportunity to provide large scale insights into modern conservation issues relating to climate change and biodiversity loss. Fundamental to the study of extinctions is disentangling potential abiotic and biotic factors involved in species decline. We present an approach combining species distribution modeling, in Maxent, with stable isotope analysis to help clarify how two ecologically distinct taxa, Mammut and Mammuthus, utilized resources during the late Quaternary (25-8 thousand years before present), concurrent with climate change. Our approach highlights differences that would not be evident with either method taken on their own: Mammut are climatically constrained, but maintain a restricted diet that varies little with climate, while Mammuthus have a more flexible diet that changes according to climate suitability. From this, we find that large-scale changes to the geographic distribution of mammoths and mastodon were unlikely to be driven by bottom-up, climate-caused losses in habitat or resource use and availability. Going forward, complementary approaches such as these may be implemented to clarify the relative impacts of abiotic and biotic influences on the ‘winners’ and ‘losers’ of past extinctions and better understand biotic responses to climate change, today.