Evidence of Lévy walk foraging patterns inhuman hunter-gatherers

When searching for food, many organisms adopt a superdiffusive,scale-free movement pattern called a Levy walk, which is considered optimal when foraging for heterogeneously located resourceswith little prior knowledge of distribution patterns [ViswanathanGM, da Luz MGE, Raposo EP, Stanley HE (2011) The Physics ofForaging: An Introduction to Random Searches and BiologicalEncounters]. Although memory of food locations and higher cognition may limit the benefits of random walk strategies, no studiesto date have fully explored search patterns in human foraging.Here, we show that human hunter-gatherers, the Hadza of northernTanzania, perform Levy walks in nearly one-half of all foragingbouts. Levy walks occur when searching for a wide variety of foodsfrom animal prey to underground tubers, suggesting that, evenin the most cognitively complex forager on Earth, such patternsare essential to understanding elementary foraging mechanisms.This movement pattern may be fundamental to how humans experience and interact with the world across a wide range of ecological contexts, and it may be adaptive to food distribution patterns onthe landscape, which previous studies suggested for organisms withmore limited cognition. Additionally, Levy walks may have becomecommon early in our genus when hunting and gathering aroseas a major foraging strategy, playing an important role in theevolution of human mobility.