Woolly mammoths (Mammuthus primigenius) were important members of Ice Age faunas until the time of their extinction, about 10,000 years ago on the Siberian mainland, and only 3700 years ago on Wrangel Island, off the northeast coast of Siberia. This project will clarify aspects of mammoth biology, the cause of mammoth extinction, and the nature of environmental change during the transition from the Ice Age to climates more typical of today's conditions. The new data that permit these advances come from mammoth tusks, the enlarged incisor teeth typical of all elephant-relatives and frequently recovered from the Arctic permafrost. Mammoth tusks formed through a life-long process of adding cone-shaped layers to the tusk base. This process was modulated by, and thus recorded, complex interactions involving climate, food resources, behavior, and reproductive history. By drilling cores of material from multiple positions along tusks and analyzing the structure and composition of the layers in these cores, we will assemble records of diet, climate, health status, migratory movements, and reproductive history. This yields a detailed picture of how mammoths responded to environmental conditions during their lifetimes, what changes were associated with their dramatic reduction in range, near the end of the Ice Age, and what changes preceded their final extinction. This project will involve fieldwork by University of Michigan and University of Minnesota Co-PIs and graduate students, along with Russian and European collaborators, in north-central Siberia, northeast Siberia, and Wrangel Island. We will collect new specimens, sample specimens in existing collections, and return samples for analysis at our home institutions. Analytical procedures will include (a) radiocarbon dating, to place each specimen in a temporal as well as a spatial context, (b) documentation of growth lines, to lay out the basic framework of life history, (c) oxygen, carbon, and nitrogen isotope analyses, to assess aspects of diet, climate, and physiology, and (d) strontium-isotope analyses to evaluate patterns of migratory movement. Mammoth tusks are a rich archive of natural history and environmental data, and this project coordinates a broad array of approaches for distilling this information and applying it to research questions in multiple fields. Collaborative aspects of this project support international cooperation in Europe and Asia, and the dramatic character of mammoths and mammoth tusks makes this work engaging for non-specialist audiences, in addition to the paleontologists, ecologists, archaeologists and climate modelers interested in the data.
