Foragers in high elevation environments thus face three significant problems. First, their basic caloric requirements are higher than those of foragers in more benign settings; this problem is exacerbated by the low productivity, high unpredictability, and heterogeneity of the high mountain environment. Second, they need to balance these demanding subsistence requirements against the necessity of other productive work, such as the making of clothing and shelter used to cope with the combined environmental stressors of extreme and constant cold and hypoxia. Third, they must accomplish these goals under the constraint of relatively high costs of movement and the transport of goods obtained through subsistence labor or exchange.
Although most research on the archaeology of high-elevation Andean foragers has not been model driven, from a theoretical perspective, a central place foraging model is a good first approximation of how high elevation foragers use a landscape (Aldenderfer 1998: 22-25, 276-279). A central place model provides a set of expectations against which an empirically-observed adaptive strategy can be evaluated. Deviations from the model can help to examine other aspects of culture change and historical contingency. Diet choice should take into account the relative energetic value of resource packages obtained, the density and value of resource patches, handling time, and processing time. Although other models of diet choice can be employed, central place foraging emphasizes the costs and benefits of moving across the landscape, which, as I have argued above, is central to understanding high mountain adaptive systems. Mobility should be logistical in form, with relatively few residential moves on an annual or seasonal basis. In tropical mountains such as the Andes in which the seasonal pulse is relatively minor and the highest elevations are often habitable year-round, the number of residential moves will be determined more by resource densities and increases in work effort than by significant changes in resource availability due to seasonal change alone. Finally, risk amelioration will be accomplished by mutual access to territory of neighboring groups as long as mobility costs, population density, and productivity remain relatively low. As population sizes and densities increase, however, exchange with neighbors becomes more likely even though productivity may remain relatively low. This can be attributed to the increased costs of residential mobility of larger groups and the decreased benefits to recipient groups as larger groups utilize their territories. Higher social costs are also likely due to increased conflict or avoidance of it.
World History
