Subsistence strategy changes during the Middle to Upper Paleolithic transition reveals specific adaptations of Human Populations to their environment

International audience; The transition from Middle to Upper Paleolithic is a major biological and cultural threshold in the construction of our common humanity. Technological and behavioral changes happened simultaneously to a major climatic cooling, which reached its acme with the Heinrich 4 event, forcing the human populations to develop new strategies for the exploitation of their environment. The recent fieldwork at Les Cottés (France) transitional site offers a good opportunity to document subsistence strategies for this period and to provide for the first time high-resolution insights on its evolution. We present the results of the complete zooarchaeological and taphonomic analysis of the transitional sequence, associated with a large regional synthesis of the subsistence strategy evolution during the Middle to Upper Paleolithic. We conclude that, while there is no major change in the hunting strategies, the butchery activities evolved in strict correlation with the development of range weapons. In addition, the demise of carnivore seems to be a consequence of the human pressure on the environment. Our study demonstrates how the faunal component of the environment became a structuring element of the human social organization, being at the base of future cultural evolutions. The Middle to Upper Paleolithic transition is well known for the major demographic shift that occurred with the arrival of anatomically modern humans (AMH) in Europe, their interbreeding with the local Neanderthal populations 1 , whom they eventually replaced. We assist to major behavioral changes with the gradual development of the cultural components of what would define the Upper Paleolithic and the cultural modernity 2. Scarce during the European late Middle Paleolithic 3-6 , evidences of symbolic behavior exploded in term of quantity and diversity in the Early Upper Paleolithic (EUP) cultural material 7-11. Significant technological advances were developed with the production of blades and notably bladelets in the Châtelperronian 12,13 , the intensification of the bladelet production with the Proto-Aurignacian and finally the individualization of their reduction sequence during the Early Aurignacian 14,15. Simultaneously, craftsmen explored and mastered new raw material 10,16,17 , bones and teeth, producing a brand-new set of tools as a response to arising needs. The development of these new needs and subsequently these new bone technologies had direct consequences on the resources procurement and management strategies and, in a more general way, on the cultural relationships constructed by human with their animal counterpart. This is specifically attested by the development of figurative art, where mammals play a quasi-exclusive role during the EUP, and the introduction of mammal bones and teeth in the personal ornaments 10 , where previously only minerals and malacofauna were used 5. These symbolic and economic transformations of the societies occurred in a changing environment characterized by the major climatic shift of the MIS3 18. In Southwestern France, the final Mousterian took place in a