Climate-Driven Dietary Change on the Colorado Plateau, USA, and Implications for Gender-Specific Foraging Patterns

Lisbeth A Louderback

doi:10.1017/aaq.2021.122

Abstract

Complementary archaeological and paleoenvironmental datasets from North Creek Shelter (Colorado Plateau, Utah, USA) are analyzed using the diet breadth model, revealing human dietary patterns during the early and middle Holocene. Abundance indices are derived from botanical and faunal datasets and, along with stone tools, are used to test the prediction that increasing aridity caused the decline of high-return resources. This prediction appears valid with respect to botanical resources, given that high-ranked plants drop out of the diet after 9800 cal BP and are replaced with low-ranked, small seeds. The prediction is not met, however, with respect to faunal resources: high-ranked artiodactyls are consistently abundant in the diet. The effects of climate change on dietary choices are also examined. Findings show that increased aridity coincides with greater use of small seeds and ground stone tools but not with increases in low-ranked fauna, such as leporids. The patterns observed from the North Creek Shelter botanical and faunal datasets may reflect different foraging strategies between men and women. This would explain why low-ranked plant resources became increasingly abundant in the diet without a corresponding decrease in abundance of high-ranked artiodactyls. If so, then archaeological records with similar datasets should be reexamined with this perspective.

Highlights

Complementary archaeological and paleoenvironmental datasets from North Creek Shelter (Colorado Plateau, Utah, USA) are analyzed using the diet breadth model, revealing human dietary patterns during the early and middle Holocene
The hypothesis that has been most often proposed to explain this dietary pattern is drawn from optimal foraging theory, which suggests that people in general only resorted to low-return small seeds after calorically higherreturn resources and high-quality resource patches diminished in abundance (O’Connell et al 1982)
The lowest abundances occur throughout strata IV (10,500–10,000 cal BP) and VI (∼7400–6700 cal BP)

Summary

Introduction

Complementary archaeological and paleoenvironmental datasets from North Creek Shelter (Colorado Plateau, Utah, USA) are analyzed using the diet breadth model, revealing human dietary patterns during the early and middle Holocene. Abundance indices are derived from botanical and faunal datasets and, along with stone tools, are used to test the prediction that increasing aridity caused the decline of high-return resources This prediction appears valid with respect to botanical resources, given that high-ranked plants drop out of the diet after 9800 cal BP and are replaced with low-ranked, small seeds. The patterns observed from the North Creek Shelter botanical and faunal datasets may reflect different foraging strategies between men and women This would explain why low-ranked plant resources became increasingly abundant in the diet without a corresponding decrease in abundance of high-ranked artiodactyls. Broad spectrum diets have been described as energetically expensive, incurring high caloric costs in harvesting, processing, and preparing food materials for human consumption (Flannery 1969) Such diets included seed, insect, and small mammal components that required different technologies and social structures to provide sufficient caloric yields. An increase in the abundance of lower-ranked resources in the diet indicates a decline in the availability of high-ranked resources and an overall reduction in foraging efficiency (Bayham 1979; Broughton and Grayson 1993; Kelly 1995a; Winterhalder and Smith 1992)

Methods

Results

Discussion

Conclusion