The ecological and evolutionary energetics of hunter-gatherer residential mobility

TL;DR

This study applies the metabolic theory of ecology to explain variations in hunter-gatherer residential mobility, linking mobility patterns to human body size and ecosystem energy availability, supported by empirical data.

Contribution

It demonstrates how ecological and evolutionary constraints, modeled by metabolic theory, predict hunter-gatherer mobility patterns and their variation across cultures.

Findings

Mobility scale correlates with human body size.

Energy availability in ecosystems predicts mobility variation.

Metabolic theory extends to behavioral ecology within species.

Abstract

Residential mobility is deeply entangled with all aspects of hunter-gatherer life ways, and is therefore an issue of central importance in hunter-gatherer studies. Hunter-gatherers vary widely in annual rates of residential mobility, and understanding the sources of this variation has long been of interest to anthropologists and archaeologists. Since mobility is, to a large extent, driven by the need for a continuous supply of food, a natural framework for addressing this question is provided by the metabolic theory of ecology. This provides a powerful framework for formulating formal testable hypotheses concerning evolutionary and ecological constraints on the scale and variation of hunter-gatherer residential mobility. We evaluate these predictions using extant data and show strong support for the hypotheses. We show that the overall scale of hunter-gatherer residential mobility is predicted by average human body size, and the limited capacity of mobile hunter-gatherers to store energy internally. We then show that the majority of variation in residential mobility observed across cultures is predicted by energy availability in local ecosystems. Our results demonstrate that large-scale evolutionary and ecological processes, common to all plants and animals, constrain hunter-gatherers in predictable ways as they move through territories to effectively exploit resources over the course of a year. Moreover, our results extend the scope of the metabolic theory of ecology by showing how it successfully predicts variation in the behavioral ecology of populations within a species.