This paper summarizes the results of my PhD thesis. In western Europe, between 12000 and 6500 BP, hunters-gatherers societies have gone through a succession of environnemental transformations including the temperate forest extension and the closing of the environment. The consequences of these transformations on their living conditions are interpreted in very opposite ways. Considering an anthropological viewpoint, this research takes a close look at the two antagonistic models that win aggreement for the status of these periods : economies of scarcity or affluent economies. Save the economic context, the "chaîne opératoire" of the predation (all the processes from procurement of animals until bones are discarded) is also analysed in order to understand the economic decisions taken by these hunter-gatherer societies : prey selection, biotopes choices, hunting techniques and treatment modalities. Results are based on an archaeozoological analysis of twenty faunal assemblages and a supra-regional bibliographic database. Between 12000 and 6500 BP no broadening spectrum evolution, neither a chronological diversification of the subsistence can be attested in these regions. Hunters used to rely on two of the highest ranked preys (red deer and wild boar). Similarly, they chose to exploit principally few biotopes : open forests and clearings. Mortality data suggest that during the Mesolithic hunting strategies were well differentiated : a high risk adult red deer hunting, a less selective and less risky wild boar hunting, and a more opportunistic small game predation. All these evidences are against the sarcity hypothesis. Other analysis suggest the existence of hunting camps (characterised by a specific composition of the squeletal parts, of the lithic industry and by the settlement structures) that were occupied seasonnally. Such hunting camps could indicate a logistical mobility of the human groups.