Hunting income patterns among the Hadza: big game, common goods, foraging goals and the evolution of the human diet.

The assumption that large mammal hunting and scavenging are economically advantageous to hominid foragers is examined in the light of data collected among the Hadza of northern Tanzania. Hadza hunters disregard small prey in favour of larger forms (mean adult mass greater than or equal to 40 kg). Here we report experimental data showing that hunters would reduce their mean rates if they included small animals in the array they target. Still, daily variance in large animal hunting returns is high, and the risk of failure correspondingly great, significantly greater than that associated with small game hunting and trapping. Sharing large kills reduces the risk of meatless days for big game hunters, and obviates the problem of storing large amounts of meat. It may be unavoidable if large carcasses cannot be defended economically against the demands of other consumers. If so, then large prey are common goods. A hunter may gain no consumption advantage from his own big game acquisition efforts. We use Hadza data to model this 'collective action' problem, and find that an exclusive focus on large game with extensive sharing is not the optimal strategy for hunters concerned with maximizing their own chances of eating meat. Other explanations for the emergence and persistence of this practice must be considered.     

Upper-body strength predicts hunting reputation and reproductive success in Hadza hunter–gatherers

Hunting is a characteristic feature of early human subsistence, and many theories of evolution have emphasized the role of hunting in hominization. Still today hunting ability continues to be selected for in extant foragers with better hunters experiencing greater reproductive success. Yet little is known about the traits that comprise a successful hunter traits that are presupposed to also be under selection. Two complementary empirical analyses were conducted to examine this question using data collected from Hadza hunter–gatherers in Tanzania. First, data on upper-body strength, running speed, target precision and visual and auditory acuity were collected to examine the traits that predict hunting reputation in men. Second, interview data were collected from Hadza informants regarding the traits they deem important for hunting. Results from the first study implicate upper-body strength as the strongest and most consistent predictor of men's hunting reputation. Hadza conventional wisdom also accord with these findings. Although informants stressed the importance of non-physical traits, such as “intelligence” and “heart”, strong arms were cited as the most important physical trait for hunting. Finally, men with stronger upper-bodies experienced greater reproductive success, a result that is largely mediated by hunting reputation. These findings suggest that selection for hunting ability may have acted on men's upper-bodies. Nevertheless, the importance of effort on strength and hunting success cannot be dismissed. This is also discussed.     

Hunting, Social Structure and Human–Nature Relationships in Lower Omo, Ethiopia: People and Wildlife at a Crossroads

Hunting is often either portrayed as the ultimate means to enact a close connection between the human being and nature, or investigated in terms of its contribution to livelihoods. Through in-depth interviews and focus group discussions, we explored the meaning of hunting in the lower Omo valley, Ethiopia, and found that large game hunting was best understood as an activity that served to establish and maintain human–human relationships. Hunting was important as it created the basis for long-term bond-relations between a hunter and his friend (‘misso’) and a hunter and his honorary elder sister (‘misha’) that could be drawn on in times of hardship. By contrast, interactions between hunter and wildlife were given hardly any attention by our participants. We discuss implications in relation to the stark decline in wildlife and the degradation of grazing land over the last decades, and the consequences of our findings for conservation and development activities.     

Duck hunter activity,success, and satisfaction on public hunting areas

Because hunting disturbance can influence local distribution of ducks and their availability to hunters, managers often limit access to hunting areas to improve hunting success and satisfaction. Few studies have quantified the effectiveness of public area access restrictions on duck hunter activity, harvest, or hunters' satisfaction with their hunting experience. We used a cross-over design over 6 consecutive hunting seasons (2008–2009 through 2013–2014) on State Wildlife Areas (SWAs) in northeastern Colorado, USA, to compare the effects of restricted hunting access regulations and regulations without these restrictions on duck hunter activity, harvest success, harvest levels, and satisfaction. We also considered effects of SWA types, duck abundance, temperature, precipitation, use of equipment by duck hunting parties, and, for hunter satisfaction, hunting success, hunting parties' satisfaction with ducks seen, habitat conditions, crowding from other hunters, and SWA regulations. The number of days when duck hunters had access to restricted properties was about half that on unrestricted properties, and unrestricted properties were used by about twice as many duck hunting parties, but the mean number of hunting parties per available hunting day and mean party size were similar under the 2 types of regulations. Most (56%) duck hunting parties did not bag any ducks; hunting success (harvest of ≥1 duck by a hunting party) was best explained by a model that included a regulation type × hunting season interaction, a SWA type × month interaction, hunter density the previous day, an index of hunter investment (number of decoys used and whether dogs and calls were used), and temperature. Successful hunting parties harvested 1.92 ± 1.60 (SD) ducks/hunter/day (range = 0.1–7.0); the best model predicting the number of ducks harvested per hunter in successful parties included a regulation type × hunting season interaction, a SWA type × month interaction, hunter density the previous day, an index of hunter investment, temperature, and precipitation. Overall satisfaction of duck hunting parties with a day's hunt averaged 3.62 ± 1.20 based on a rank scale of 1 (very unsatisfied) to 5 (very satisfied), and was best explained by a model that included hunting party success; hunter investment; temperature; and satisfaction with duck numbers, habitat conditions, hunting regulations, and crowding. While greatly reducing days available for hunting, access restrictions were associated with improved chances of hunting parties successfully harvesting ≥1 duck in 5 of 6 hunting seasons, and substantially greater numbers of ducks harvested by hunters in successful parties in 1 of 6 hunting seasons. Restrictions did not have a strong direct effect on hunting parties' satisfaction with a day's hunt. Uncontrolled factors, including weather and use of equipment by hunters, had important influences on hunter success, harvest, and satisfaction. Managers should carefully assess hunting activity, hunter expectations and desires, and hunting area characteristics when considering access restrictions on public hunting areas.     

From subsistence to market: A case study of the mbuti net hunters

This article describes the recent transition from subsistence to market hunting of some net-hunting Mbuti, a nomadic society of the Ituri Forest of Zaire. The history of this development dates to the late 1950s, as the Mbuti began to have increasing contact with commercial meat traders, called bachuuzi, from outside markets. Before this, the Mbuti had a long history of contact with local swidden agriculturalists, called bakbala, a relationship that continues today. It is sanctioned by religious beliefs, but material exchanges are also important. The Mbuti provide bakbala with meat and other forest resources and receive in return iron implements, tobacco, and cultivated food. The Mbuti view such items now as necessities; however, this does not allow the bakbala to subjugate or control them. Most exchanges take place in the bakbala's village at the Mbuti's discretion, and exchange rates are not fixed. Finally it appears that such trade does not undermine the resource base of either group. The Mbuti's commercial exchanges contrast with this subsistence-oriented system. Unlike the bakbala, the bachuuzi traders establish themselves in the Mbuti's forest camps, where they can promote intensified net hunting and monopolize trade of meat. The Mbuti tolerate the alien traders in camp because they are often a convenient source of food and other desired material goods; however, they do not share the traders' commercial motives. The Mbuti freely manipulate credit to their own advantage and they are often able to evade the traders' efforts at economic control. The future of market hunting is uncertain. Mbuti material needs are changing and the antelope fauna (Cephalophinae) upon which commercial trade depends is being reduced in some areas.A fellowship from the Thomas J. Watson Foundation provided financial support for this research. I am also thankful to Citoyen Bokanga Ekanga Botombele, Commissaire d'Etat du Zaire for his interest in my work and support in obtaining necessary visas, and to Père Thyert of the Catholic Mission of Biambwe for his generous hospitality. Terese Butler Hart, Colin Turnbull, Paul Riesman, Randall Packard, Paul Wholt, and Stuart Marks criticized drafts of this paper. Finally, I am most grateful to the Mbuti with whom I lived for so generously sharing their daily life with me.     

Hunter Movement and its Role in National Game Bird Surveys

Analysis of sample survey data on the species composition of waterfowl kill for resident and nonresident hunters for provinces of Canada during 1974 and 1975 showed that a successful game bird hunter who hunted in more than one area (degree block) had both a higher average season kill and more successful days of hunting in which one or more birds were bagged, than one who hunted in the same area during the season. Adjustment for days hunted resulted in a higher daily hunting for those who hunted in more than one degree block. However, the higher kill of the successful hunter is attributable more to a larger number of days hunted than to a larger kill per successful day. Also, hunters hunting in more than one degree block had their successful hunting days more evenly spread across the season. The estimates of kill per successful hunter and days hunted for stratified sampling by areas of hunting were considerably more efficient than simple random sampling.     

No evidence of short-term exchange of meat for sex among chimpanzees

The meat-for-sex hypothesis posits that male chimpanzees (Pan troglodytes) trade meat with estrous females in exchange for short-term mating access. This notion is widely cited in the anthropological literature and has been used to construct scenarios about human evolution. Here we review the theoretical and empirical basis for the meat-for-sex hypothesis. We argue that chimpanzee behavioral ecology does not favor the evolution of such exchanges because 1) female chimpanzees show low mate selectivity and require little or no material incentive to mate, violating existing models of commodity exchange; and 2) meat-for-sex exchanges are unlikely to provide reproductive benefits to either partner. We also present new analyses of 28 years of data from two East African chimpanzee study sites (Gombe National Park, Tanzania; Kanyawara, Kibale National Park, Uganda) and discuss the results of previously published studies. In at least three chimpanzee communities, 1) the presence of sexually receptive females did not increase hunting probability, 2) males did not share preferentially with sexually receptive females, and 3) sharing with females did not increase a male's short-term mating success. We acknowledge that systematic meat sharing by male chimpanzees in expectation of, or in return for, immediate copulations might be discovered in future studies. However, current data indicate that such exchanges are so rare, and so different in nature from exchanges among humans, that with respect to chimpanzees, sexual bartering in humans should be regarded as a derived trait with no known antecedents in the behavior of wild chimpanzees.     

Evolutionary Implications of Persistence Hunting: An Examination of Energy Return on Investment for !Kung Hunting

Hominins are smaller, slower, and weaker than most large mammals, yet they have been eating meat from freshly killed large mammals since before the invention of sophisticated weaponry. It is thought that they could have achieved this seemingly impossible feat through persistence hunting, a practice powered by endurance running. Essentially, one or more hunters pursue a prey animal in the heat of the day until it reaches the point of hyperthermia. This allows a hunter to safely kill the weakened animal at close range using methods such as beating, strangling, or spearing. The energy balance of this approach to getting food is controversial and has not been calculated previously. We examined the energy costs and gains of persistence hunting through several energy returned on investment (EROI) calculations based on synthesizing available field and laboratory data on the energy used by the hunters and the energy returned from the greater kudu (Tragelaphus strepsiceros). We estimate that the EROI of these hunter-gatherers hunting a kudu ranged from 26:1 to 69:1. The net energy gained from such an effort would sustain an average sized !Kung family for 6.7 to 11.2 days. The “profit” energy within these ranges would have supported the early human societies that practiced persistence hunting, contributing to the often-noted “leisure” characterizing many foraging societies (Sahlins 1974).     

Household and Kin Provisioning by Hadza Men

We use data collected among Hadza hunter-gatherers between 2005 and 2009 to examine hypotheses about the causes and consequences of men’s foraging and food sharing. We find that Hadza men foraged for a range of food types, including fruit, honey, small animals, and large game. Large game were shared not like common goods, but in ways that significantly advantaged producers’ households. Food sharing and consumption data show that men channeled the foods they produced to their wives, children, and their consanguineal and affinal kin living in other households. On average, single men brought food to camp on 28% of days, married men without children at home on 31% of days, and married men with children at home on 42% of days. Married men brought fruit, the least widely shared resource, to camp significantly more often than single men. A model of the relationship between hunting success and household food consumption indicates that the best hunters provided 3–4 times the amount of food to their families than median or poor hunters. These new data fill important gaps in our knowledge of the subsistence economy of the Hadza and uphold predictions derived from the household and kin provisioning hypotheses. Key evidence and assumptions backing prior claims that Hadza hunting is largely a form of status competition were not replicated in our study. In light of this, family provisioning is a more viable explanation for why good hunters are preferred as husbands and have higher fertility than others.     

Bear-Baiting May Exacerbate Wolf-Hunting Dog Conflict

Background

The influence of policy on the incidence of human-wildlife conflict can be complex and not entirely anticipated. Policies for managing bear hunter success and depredation on hunting dogs by wolves represent an important case because with increasing wolves, depredations are expected to increase. This case is challenging because compensation for wolf depredation on hunting dogs as compared to livestock is less common and more likely to be opposed. Therefore, actions that minimize the likelihood of such conflicts are a conservation need.

Methodology/Principal Findings

We used data from two US states with similar wolf populations but markedly different wolf/hunting dog depredation patterns to examine the influence of bear hunting regulations, bear hunter to wolf ratios, hunter method, and hunter effort on wolf depredation trends. Results indicated that the ratio of bear hunting permits sold per wolf, and hunter method are important factors affecting wolf depredation trends in the Upper Great Lakes region, but strong differences exist between Michigan and Wisconsin related in part to the timing and duration of bear-baiting (i.e., free feeding). The probability that a wolf depredated a bear-hunting dog increases with the duration of bear-baiting, resulting in a relative risk of depredation 2.12–7.22× greater in Wisconsin than Michigan. The net effect of compensation for hunting dog depredation in Wisconsin may also contribute to the difference between states.

Conclusions/Significance

These results identified a potential tradeoff between bear hunting success and wolf/bear-hunting dog conflict. These results indicate that management options to minimize conflict exist, such as adjusting baiting regulations. If reducing depredations is an important goal, this analysis indicates that actions aside from (or in addition to) reducing wolf abundance might achieve that goal. This study also stresses the need to better understand the relationship among baiting practices, the effect of compensation on hunter behavior, and depredation occurrence.     

Public Access for Pheasant Hunters: Understanding an Emerging Need

Ring-necked pheasant (Phasianus colchicus; i.e., pheasant) hunting participation is declining across North America, reflecting a larger downward trend in American hunting participation and threatening benefits to grassland conservation and rural economies. To stabilize and expand the pheasant hunting population, we must first identify factors that influence pheasant hunter participation. We used an extensive in-person hunter survey to test the hypothesis that hunter demographics interact with social-ecological traits of hunting locations to affect hunter decisions, outcomes, and perceptions. We built a series of Bayesian mixed effects models to parse variation in demographics, perceptions, and hunt outcomes of pheasant hunters interviewed at public access hunting sites across 3 regions in Nebraska, USA, that varied in pheasant abundance and proximity to urban population centers. Among pheasant hunters in Nebraska, access to private lands was negatively related to the human population density of a pheasant hunter's home ZIP code and the distance a hunter had traveled to reach a hunting location. Pheasant hunters interviewed closer to metropolitan areas tended to be more urban and travel shorter distances, and their parties were more likely to include youth but less likely to include dogs. Hunter satisfaction was positively associated with seeing and harvesting pheasants and hunting with youth. Whereas youth participation and the number of pheasants seen varied by study region, hunter satisfaction did not differ across regions, suggesting that hunters may calibrate their expectations and build their parties based on where they plan to hunt. The variation in hunter demographics across hunting locations and disconnects between social and ecological correlates of hunter satisfaction suggests that diverse pheasant hunting constituencies will be best served by diverse pheasant hunting opportunities. © 2019 The Wildlife Society.     

Social sharing and risk reduction: Exploring a computational algorithm for the psychology of windfall gains

Sharing important resources widely beyond direct kin group members is one of the core features characterizing human societies. Moreover, generalized exchange involving many community members (e.g., meat sharing in bands) seems to be a uniquely human practice. This paper explores a computational algorithm for the psychology of social sharing that may underlie such practices, based on the risk-reduction hypothesis in food sharing of Kaplan and Hill [Curr. Anthropol. 26 (1985) 223]. We predicted that, independent of the amount of effort actually invested, uncertainty involved in resource acquisition is a key factor that triggers the psychology of social sharing for both acquirers and nonacquirers of a resource. It was also predicted that the “windfall effect” is independent of individual preferences as to modern distributive ideologies. Four multisample/multimethod studies, using Japanese and American participants, and laboratory as well as vignette experiments, supported these predictions: although the identical fungible resource (money) was under consideration, different psychological processes were triggered, depending on the degree of uncertainty involved in the money acquisition. Implications of the windfall effect for egalitarianism in resource sharing, observed not only in hunter–gatherer bands but also in highly industrialized societies, are discussed.     

Hunting Behavior of Chimpanzees at Ngogo,Kibale National Park,Uganda

Chimpanzees (Pan troglodytes) prey on a variety of vertebrates, mostly on red colobus (Procolobus spp.) where the two species are sympatric. Variation across population occurs in hunting frequency and success, in whether hunting is cooperative, i.e., payoffs to individual hunters increase with group size, and in the extent to which hunters coordinate their actions in space and time, and in the impact of hunting on red colobus populations. Also, hunting frequency varies over time within populations, for reasons that are unclear. We present new data on hunting by chimpanzees at Ngogo, Kibale National Park, Uganda, and combine them with earlier data (Mitani and Watts, 1999, Am. J. Phys. Anthropol. 109: 439–454) to examine hunting frequency and success, seasonality, and cooperation. The Ngogo community is the largest and has the most males of any known community. Chimpanzees there mostly hunt red colobus and are much more successful and make many more kills per hunt than at other sites; they kill 6–12% of the red colobus population annually. The number of kills and the offtake of meat per hunt increase with the number of hunters, but per capita meat intake is independent of hunting party size; this suggests that cheating occurs in large parties. Some behavioral cooperation occurs. Hunting success and estimated meat intake vary greatly among males, partly due to dominance rank effects. The high overall success rate leads to relatively high average per capita meat intake despite the large number of consumers. The frequency of hunts and of hunting patrols varies positively with the availability of ripe fruit; this is the first quantitative demonstration of a relationship between hunting frequency and the availability of other food, and implies that the chimpanzees hunt most when they can easily meet energy needs from other sources. We provide the first quantitative support for the argument that variation in canopy structure influences decisions to hunt red colobus because hunts are easier where the canopy is broken.     

‘Impact hunters’ catalyse cooperative hunting in two wild chimpanzee communities

Even when hunting in groups is mutually beneficial, it is unclear how communal hunts are initiated. If it is costly to be the only hunter, individuals should be reluctant to hunt unless others already are. We used 70 years of data from three communities to examine how male chimpanzees ‘solve’ this apparent collective action problem. The ‘impact hunter’ hypothesis proposes that group hunts are sometimes catalysed by certain individuals that hunt more readily than others. In two communities (Kasekela and Kanyawara), we identified a total of five males that exhibited high hunt participation rates for their age, and whose presence at an encounter with red colobus monkeys increased group hunting probability. Critically, these impact hunters were observed to hunt first more often than expected by chance. We argue that by hunting first, these males dilute prey defences and create opportunities for previously reluctant participants. This by-product mutualism can explain variation in group hunting rates within and between social groups. Hunting rates declined after the death of impact hunter FG in Kasekela and after impact hunter MS stopped hunting frequently in Kanyawara. There were no impact hunters in the third, smaller community (Mitumba), where, unlike the others, hunting probability increased with the number of females present at an encounter with prey.     

Showoffs or Providers? The Parenting Effort of Hadza Men

Paternal care plays an important role in many scenarios of human evolution. Lately, however, this “Man the Provisioner” view has been challenged. The showoff hypothesis, for example, proposes that men hunt not to provision children but to gain extra mating opportunities, and some have suggested that male care among mammals is always a form of mating, rather than parenting, effort. This study, based on observation in a hunting and gathering society, the Hadza of Tanzania, tests whether men provide care as parenting effort. If male care were mating effort only, stepchildren should receive no less care than biological children. My data, however, reveal that stepchildren do receive less care. This suggests that care is provided, at least in part, as parenting effort. Although lower direct care implies stepfathers are less motivated to care for stepchildren, resource acquisition data raise the question of whether stepfathers are less motivated, or simply less skilled.     

Birth Order, Age, and Hunting Success in the Canadian Arctic

What explains variation in hunting success? This paper examines foraging success among Inuit hunters, paying particular attention to factors that account for differential returns in hunting. Although there are several possibilities for explaining hunting success, this study finds that birth order and age are important predictors of foraging returns. Furthermore, data on food sharing suggests that birth order has important effects on the distribution of food. That is, early-born hunters not only produce more food, they give much of that food to their parents, who then distribute it to the hunter’s younger siblings. These findings are discussed within the context of local resource enhancement and the value of early-born sons to Inuit parents.     

Sex Differences in Hadza Dental Wear Patterns

Among hunter-gatherers, the sharing of male and female foods is often assumed to result in virtually the same diet for males and females. Although food sharing is widespread among the hunting and gathering Hadza of Tanzania, women were observed eating significantly more tubers than men. This study investigates the relationship between patterns of dental wear, diet, and extramasticatory use of teeth among the Hadza. Casts of the upper dentitions were made from molds taken from 126 adults and scored according to the Murphy dental attrition scoring system. Females had significantly greater anterior occlusal wear than males when we controlled for age. Males exhibited greater asymmetry in wear, with greater wear on the left side in canines, first premolars, and first molars. We suggest that these sex differences in wear patterns reflect the differences seen in the diet, as well as in the use of teeth as tools.     

A noisy signal: To what extent are Hadza hunting reputations predictive of actual hunting skills?

The measurement of hunting ability has been central to several debates about the goals of men's hunting among the Hadza and other hunter-gatherer populations. Hunting ability has previously been measured indirectly, by weighing the amount of food individuals bring back to camp over an extended period, their central place hunting return rate, and by conducting hunting ability interviews. Despite the centrality of the hunting ability concept, some authors (Hill & Kintigh, 2009) have expressed scepticism that such measures accurately capture individual differences in actual hunting ability. In the current study, we introduce a novel measure of hunting reputation which, unlike previous ones, allows fine-grained distinction between hunters of all reputations. To assess the suitability of this measure as a viable proxy for hunting ability, we address two further questions. First, to what extent do interviewees agree about the hunting ability of their present and former campmates? Second, to what extent does this measure of hunting reputation reflect success in four tasks expected to capture important components of hunting ability? We demonstrate that these measures of hunting reputation appear to reflect variation in these skills. We argue, however, that hunting reputation appears too noisy an index of these skills and, we infer, hunting ability in general for hunting to act, as some have suggested (e.g. Hawkes & Bird, 2002), as an honest signal of cryptic qualities related to hunting ability.     

Effects of hunter access and habitat security on elk habitat selection in landscapes with a public and private land matrix

Traditional elk habitat management on public land has focused on providing security habitat for bull elk during the hunting season to provide for both adequate hunter opportunity and bull survival. This paradigm has given less consideration to adult female elk habitat use, patterns of adjacent land ownership, and hunter access. This paradigm also was developed when elk population sizes were much smaller in many areas. In many Rocky Mountain states, the focus of elk population management has recently shifted to reducing or maintaining elk population sizes, necessitating a better understanding of the implications of security habitat management, as well as patterns of adjacent land ownership and hunter access, on adult female elk. We addressed this need by testing the hypotheses that during the hunting season: 1) adult female elk selection for areas prohibiting or limiting hunter access is stronger than elk selection for publicly owned and managed elk security habitat, 2) these effects occur during the archery hunting period and intensify during the rifle hunting period, and 3) the effects of hunter access on selection are consistent among herds that occupy landscapes characterized by a matrix of public and private lands. We used global position system locations collected from 82 females in 2 different Greater Yellowstone Ecosystem (GYE) elk herds to evaluate effects of hunter access, security habitat as defined by the Hillis paradigm, and other landscape attributes on adult female elk resource selection during the pre-hunting, archery, rifle, and post-hunting periods. We found that female elk selection for areas restricting public hunting access was stronger than selection for security habitat in both study areas, and that the density of roads open to motorized use was the strongest predictor of elk distribution. Increases in selection for areas that restricted hunting access occurred during the rifle hunting period, and we did not find consistent evidence these movements were triggered by the archery hunting period. Our results provide evidence that in landscapes characterized by a matrix of public and privately owned lands, traditional concepts of elk security habitat need to be expanded to also include areas that restrict hunter access to plan for elk population management that is regulated through adult female harvest. Future efforts should investigate whether elk use of areas that restrict hunter access are flexible behavioral responses to hunting risk, or if these behaviors are passed from generation to generation such that a learned pattern of private land use becomes the normal movement pattern rather than a short-term behavioral response. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.