Provisioning offspring and others: Risk-energy trade-offs and gender differences in hunter-gatherer foraging strategies

Offspring provisioning is commonly referenced as the most important influence on men's and women'sforaging decisions. However, the provisioning of other adults may be equally important in determininggender differences in resource choice, particularly when the goals of provisioning offspring versusothers cannot be met with the acquisition of the same resources. Here, we examine how resources varyin their expected daily energetic returns and in the variance or risk around those returns. We predictthat when available resources impose no trade-off between risk and energy, the targets of men's andwomen's foraging will converge on high-energy, low-risk resources that allow for the simultaneous provisioningof offspring and others. However, when minimizing risk and maximizing energy trade-off with oneanother, we expect men's foraging to focus on provisioning others through the unreliable acquisition oflarge harvests, while women focus on reliably acquiring smaller harvests to feed offspring. We testthese predictions with foraging data from three populations (Aché, Martu and Meriam). The resultsuphold the predictions, suggesting that men's and women's foraging interests converge when highenergyresources can be reliably acquired, but diverge when higher-energy resources are associatedwith higher levels of risk. Social factors, particularly the availability of alloparental support, may alsoplay a major role.