Gendered movement ecology and landscape use in Hadza hunter-gatherers

Brian M Wood,David A Raichlen,Richard Mcelreath,Audax Mabulla,James Holland Jones,Katherine Sayre,Elizabeth Cashdan,Colette Berbesque,Herman Pontzer,Amelia Sancilio,Jacob A Harris,Alyssa N Crittenden

doi:10.1038/s41562-020-01002-7

Abstract

Understanding how gendered economic roles structure space use is critical to evolutionary models of foraging behaviour, social organization and cognition. Here, we examine hunter-gatherer spatial behaviour on a very large scale, using GPS devices worn by Hadza foragers to record 2,078 person-days of movement. Theory in movement ecology suggests that the density and mobility of targeted foods should predict spatial behaviour and that strong gender differences should arise in a hunter-gatherer context. As predicted, we find that men walked further per day, explored more land, followed more sinuous paths and were more likely to be alone. These data are consistent with the ecology of male- and female-targeted foods and suggest that male landscape use is more navigationally challenging in this hunter-gatherer context. Comparisons of Hadza space use with space use data available for non-human primates suggest that the sexual division of labour likely co-evolved with increased sex differences in spatial behaviour and landscape use.

Highlights

Our species’ use of space is exceptional in many regards
Our study demonstrates that substantial gender differences in spatial behaviour were present across the life course in this hunter-gatherer society
Among the Hadza, men travelled further, visited more areas of the landscape, followed more sinuous routes and were more solitary while foraging. These patterns are consistent with the gendered ecology of hunting and gathering, in which men search for rarer, more energy-dense and more mobile resources than women[23,26,27,46]

Summary

Introduction

Our species’ use of space is exceptional in many regards. At a global level, our distribution across the earth’s habitats attests to an unrivalled capacity to explore and adapt to novel environments. Some basic measures of spatial cognition, including three-dimensional mental rotation and dead reckoning, have been studied in many human populations, and research to date shows that in these two measures, average male scores are characteristically higher than those of women[6,7] Some have ascribed this result to our species’ evolutionary history of hunting and gathering[8], while others propose that ranging patterns established prior to the advent of the sexual division could account for these sex differences[9]. Vincent[27] reports that two dietary staples targeted by Hadza women, the tubers //ekwa (Vigna frutescens) and shumuko (Vatovaea pseudolablab), were found at levels averaging 5,200 kg hectare−1 and 63,000 kg hectare−1, respectively These data illustrate a stark difference in the availability of male- and female-targeted foods

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Conclusion