Original Article Mutualism and manipulation in Hadza–honeyguide interactions Brian M. Wood a, ⁎, Herman Pontzer b , David A. Raichlen c , Frank W. Marlowe d a Department of Anthropology, Yale University, 10 Sachem Street, New Haven, CT 06511 USA b Department of Anthropology, Hunter College, 695 Park Ave, NY, NY 10065 USA c School of Anthropology, University of Arizona, 1009 East South Campus Drive, Tucson, AZ 85721 USA d Biological Anthropology Unit, Department of Archaeology and Anthropology, University of Cambridge, Pembroke Street, Cambridge, CB2 3QG, UK abstract article info Article history: Initial receipt 16 December 2013 Final revision received 21 July 2014 Available online xxxx Keywords: Hunter-Gatherers Indicator indicator Honeyguide Honey Interspecific cooperation Manipulation Mutualism We investigated the ecology and evolution of interspecific cooperation between the Greater Honeyguide bird, Indicator indicator, and human hunter-gatherers, the Hadza of northern Tanzania. We found that honeyguides increased the Hadza's rate of finding bee nests by 560%, and that the birds led men to significantly higher yielding nests than those found without honeyguides. We estimate that 8–10% of the Hadza's total diet was acquired with the help of honeyguides. Contrary to most depictions of the human-honeyguide relationship, the Hadza did not actively repay honeyguides, but instead, hid, buried, and burned honeycomb, with the intent of keeping the bird hungry and thus more likely to guide again. Such manipulative behavior attests to the importance of social intelligence in hunter-gatherer foraging strategies. We present an evolutionary model for human-honeyguide interactions guided by the behavioral ecology of bees, non-human primates, and hunter-gatherers. © 2014 Elsevier Inc. All rights reserved. 1. Introduction When searching their woodlands for nests of honey bees, Hadza hunter-gatherers are often helped by the Greater Honeyguide (Indicator indicator, hereafter ‘honeyguide’), a bird that flies ahead of them, leading them to nests of the honey bee, Apis mellifera. In this article, we 1) describe how Hadza and honeyguides interacted; 2) test whether honeyguides changed the Hadza’s efficiency at finding honey; 3) estimate the fraction of the Hadza’s diet that was acquired with honeyguides’ help; 4) examine how and why the Hadza manipulate honeyguides; 5) discuss the evolution of this relationship. These research questions arise as part of our ongoing studies of Hadza behavioral ecology (Marlowe, 2003, 2010; Marlowe & Berbesque, 2009; Pontzer et al., 2012; Raichlen et al., 2014; Wood, 2006; Wood & Marlowe, 2013). Here, we are guided by theories of the evolution and maintenance of social foraging strategies, using rates of energy capture as a proxy variable for fitness benefits (Smith & Winterhalder, 1992; Winterhalder, 1996). We define mutualism in the standard manner as an interaction that provides net benefits to both parties, and commensalism as an interaction which provides net benefits to one party and does no harm to the other (Boucher, James, & Keeler, 1982; Connor, 1995). We use the term manipulation here to refer to an act by partner A that causes partner B to alter its behavior in a way that is beneficial to A and marginally costly to B. Archaeologists have paid special attention to the role of mutual- istic interactions between humans and other species, largely in order to understand the processes of plant and animal domestication (Rindos, 1980). One goal of this paper is to provide a case study of cooperation between humans and a wild animal partner. We hope this study will help foster an appreciation for the diverse ways in which people like the Hadza engage and influence their ecosystems, embedded in a full suite of species interactions including but not restricted to predation. 1.1. Hadza, honey, and honeyguides The Hadza are an ethnic group that has traditionally subsisted from hunting and gathering who live in northern Tanzania near Lake Eyasi (latitude -3.3 to 4.0; longitude 34.6–35.6; elevation 1200–1600 m). Today there exist approximately 1200 speakers of the Hadza language, among whom about 250 continue to hunt and gather with traditional technologies for approximately 95% of their total diet. More ethno- graphic details and information about Hadza subsistence can be found in other publications (Marlowe, 2010; Wood & Marlowe, 2013). In cultures around the world, honey is highly prized as food and medicine, and there is no known culture with a taboo prohibiting its consumption 1 . Honey forms an important part of the diet of many Evolution and Human Behavior xxx (2014) xxx–xxx ⁎ Corresponding author. 10 Sachem Street, New Haven, CT 06511 USA. E-mail address: brian.wood@yale.edu (B.M. Wood). 1 Based on a search of 258 cultures coded in eHraf World Cultures. 5 cultures (2%) have transient prohibitions against consumption of some types of honey by a subset of the population during political gatherings, initiation rites, religious gatherings, and crop plantings. http://dx.doi.org/10.1016/j.evolhumbehav.2014.07.007 1090-5138/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Evolution and Human Behavior journal homepage: www.ehbonline.org Please cite this article as: Wood, B.M., et al., Mutualism and manipulation in Hadza–honeyguide interactions, Evolution and Human Behavior (2014), http://dx.doi.org/10.1016/j.evolhumbehav.2014.07.007