Sego Lilies and Prehistoric Foragers: Return Rates, Pit Ovens, and Carbohydrates

Three experiments or simulations were undertaken to obtain a clearer understanding of the role of pit ovens and roots from dry, sagebrush-covered habitats in prehistoric forager subsistence. The archaeological record of north-central Wyoming containing cylindrical pits near dense stands of sego lily served as a model for these studies. They revealed that: (1) the post-encounter return rates for collecting and processing sego lily is relatively low at 207kcal/h; (2) the design of pit ovens of this sort was for long-term moderate heat; and (3) long-term moderate heat transformed the large complex polysaccharides (probably starch) of sego lily into more easily digestible disaccharides and monosaccharides. Given the results of the experiments and archaeological and ethnographic evidence, small groups of foragers probably baked sego lily bulbs or a similar resource near the collection patches for immediate consumption. The use of this predictable, stationary resource would have served to buffer risk and would have provided required carbohydrates in the spring at the end of the nutritionally stressful time of the year.