An Optimal Foraging Perspective on Early Holocene Human Prey Choice on Gotland : Affluence or Starvation?

Abstract: The Optimal Foraging Theory, rooted in the processual archaeology, uses a measuring methodology where the foraging strategy that gives the highest payoff measured as the highest ratio of energy gain per time unit is analysed (Mac Arthur & Pianca 1966, Emlen 1966). The theory is a branch of evolutionary ecology why much attention is paid to the interdependence of humans and preys and environmental conditions caused by climatologically and geographical changes or by overexploitation or other changes caused by humans. The analysis of Early Mesolithic pioneers onGotland, who settle in a transforming landscape, leaves indications of a Maglemose culture origin, probably from flooded original settlements in the south/southwest Baltic basin. The pioneers have to adapt to a seal-hunting economy dominated by grey seal which give the best cost-benefit outcome as big terrestrial mammals are missing and only mountain hare is available. The diet is narrow and there is a great risk for deficiency diseases as well as for acquiring hypervitaminosis and osteoporosis caused by excess of seal food. There is a hiatus c. 5000-4500 BC in the archaeological records on Gotland and the south-western Baltic region, and the master thesis hypothesises that Littorina Transgression I with a severe cold dip called the “8.2 ka BP cold event” has a delayed, but such a severe impact also on fauna and flora on Gotland, that the ecological system is destroyed. The possibility for humans to survive in a sustainable society is questionable. The extremely cold winters during this c. 400 years cold event, with glaciers moving southwards, delayed the blooming season, diminished the harvest and changed both flora and fauna. When the ecological niche for the grey seal is destroyed with flooded beaches close to the pioneers, human overexploitation is reinforced. With a diminishing population of mountain hare, which eventually gets extinct at the end of the Mesolithic, there are no alternatives but some birds and fish, hard to catch. Probably the pioneers abandon Gotland or move to a higher level on Gotland but no records are yet found why the period is called a hiatus. Extinction is the worst scenario or survival in such a small number that a sustainable society is lost. If so, new population groups repopulatedGotlandafter the Littorina transgressions. The origin is still unknown of the Pitted-ware and Funnelbeaker cultures that are populating Gotland after the transgressions. This master thesis can not confirm an affluent life style but rather a suffering starving society flooded by Littorina transgressions and struggling with the severe cold, caused by the “8.2 ka cold event” that makes the environmental conditions even worse. The subsistence economy is successively destroyed which probably causes the hiatus in archaeological records. The Littorina Transgression I with the “8.2 cold event” and the lack of terrestrial big animals are bottle necks.