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As the world's most ubiquitous carnivore, domestic dogs maintain unique proximity to human populations. Partly because dogs potentially serve as hosts of zoonotic diseases, determinants of canine health are increasingly the focus of interdisciplinary research. Emerging perspectives suggest that dogs' health may vary as a function of their owners' wealth and financial resources, a correlation that could potentially inform public health programs and conservation efforts. The objective of this study was to evaluate associations between household wealth and the health of domestic dogs (n = 208) among indigenous Mayangna communities in the Bosawás Biosphere Reserve, Nicaragua. The dogs were evaluated using serum biochemistry, complete blood count, and physical exam findings. Using these data, a principal components analysis (PCA) determined the presence of four "syndromes": 1) decreased body condition score (BCS) & hypoalbuminemia; 2) lymphocytosis & eosinophilia; 3) segmented neutrophilia; and 4) lymphadenopathy, tick infestation, & hyperglobulinemia. An inventory of possessions indexed household wealth. For all four syndromes, household wealth was a weak and uninformative predictor of the dogs' health. The few differences seen among dogs from households with different degrees of wealth likely reflect that nearly all dogs had marginal health and all households were relatively poor. Results from this study imply that owners' wealth may have diverse effects on canine health in rural settings.

Hunters exhibit high skill across the life span, individuals vary substantially in skill, and age-related peaks vary across sites., Human adaptation depends on the integration of slow life history, complex production skills, and extensive sociality. Refining and testing models of the evolution of human life history and cultural learning benefit from increasingly accurate measurement of knowledge, skills, and rates of production with age. We pursue this goal by inferring hunters’ increases and declines of skill from approximately 23,000 hunting records generated by more than 1800 individuals at 40 locations. The data reveal an average age of peak productivity between 30 and 35 years of age, although high skill is maintained throughout much of adulthood. In addition, there is substantial variation both among individuals and sites. Within study sites, variation among individuals depends more on heterogeneity in rates of decline than in rates of increase. This analysis sharpens questions about the coevolution of human life history and cultural adaptation.

Becoming valuable to fellow group members so that one would attract assistance in times of need is a major adaptive problem. To solve it, the individual needs a predictive map of the degree to which others value different acts so that, in choosing how to act, the payoff arising from others’ valuation of a potential action (e.g., showing bandmates that one is a skilled forager by pursuing a hard-to-acquire prey item) can be added to the direct payoff of the action (e.g., gaining the nutrients of the prey captured). The pride system seems to incorporate all of the elements necessary to solve this adaptive problem. Importantly, data from western(-ized), educated, industrialized, rich, and democratic (WEIRD) societies indicate close quantitative correspondences between pride and the valuations of audiences. Do those results generalize beyond industrial mass societies? To find out, we conducted an experiment among 567 participants in 10 small-scale societies scattered across Central and South America, Africa, and Asia: (i) Bosawas Reserve, Nicaragua; (ii) Cotopaxi, Ecuador; (iii) Drâa-Tafilalet, Morocco; (iv) Enugu, Nigeria; (v) Le Morne, Mauritius; (vi) La Gaulette, Mauritius; (vii) Tuva, Russia; (viii) Shaanxi and Henan, China; (ix) farming communities in Japan; and (x) fishing communities in Japan. Despite widely varying languages, cultures, and subsistence modes, pride in each community closely tracked the valuation of audiences locally (mean r = +0.66) and even across communities (mean r = +0.29). This suggests that the pride system not only develops the same functional architecture everywhere but also operates with a substantial degree of universality in its content.

Author(s): Ross, Cody T; Mulder, Monique Borgerhoff; Oh, Seung-Yun; Bowles, Samuel; Beheim, Bret; Bunce, John; Caudell, Mark; Clark, Gregory; Colleran, Heidi; Cortez, Carmen; Draper, Patricia; Greaves, Russell D; Gurven, Michael; Headland, Thomas; Headland, Janet; Hill, Kim; Hewlett, Barry; Kaplan, Hillard S; Koster, Jeremy; Kramer, Karen; Marlowe, Frank; McElreath, Richard; Nolin, David; Quinlan, Marsha; Quinlan, Robert; Revilla-Minaya, Caissa; Scelza, Brooke; Schacht, Ryan; Shenk, Mary; Uehara, Ray; Voland, Eckart; Willfuhr, Kai; Winterhalder, Bruce; Ziker, John | Abstract: With apologies, an incorrect author list was given in the article. An additional author, Chris von Rueden, (Jepson School of Leadership Studies, University of Richmond) also contributed to this work. Author Ryan Schacht's affiliation was out-of-date. His correct affiliation is: Department of Anthropology, East Carolina University.

Dietary reconstruction via stable isotope analysis is an important part of the study of past populations, but can raise issues in many parts of the world where human remains are scarce, absent, or restricted due to ethical concerns. Given these issues, some researchers have used domesticated dogs as human dietary proxies via the Canine Surrogacy Approach (CSA). We performed carbon and nitrogen stable isotope analysis on the hair of 304 humans and 57 dogs from 45 households in two contemporary indigenous communities in Nicaragua’s Bosawas Biosphere Reserve to explore whether dogs function as dietary proxies for their human owners in this Neotropical horticulturalist context. While CSA is broadly viable at these study sites, on a more precise scale the diets of dogs do not reflect the diets of their owners. This raises questions about the applicability of CSA to archaeological contexts, suggesting that relying on dogs as dietary proxies may overlook key variation in past human diets.

Given the complexity of human foraging strategies, especially hunting, recent attention has focused on the ways in which hunters acquire needed knowledge and skills, including via social learning. One potentially useful heuristic is a “conformist bias,” in which individuals identify and adopt the most common beliefs or strategies, but the usefulness of this heuristic depends on the accuracy of the information. In this study, 45 indigenous Mayangna and Miskito informants in Nicaragua were asked to rank 17 game species on the extent to which harvests of these species are associated with the use of hunting dogs. Consensus analysis indicates that there is high agreement on the rankings, and the aggregated rankings closely reflect harvest data from a yearlong study that documented the use of dogs and other hunting accessories (e.g., firearms). There were noteworthy outliers in the analysis, however, and a possible explanation is that informants are inferring that dogs are useful for some species because they are valuable for hunting perceptually similar species, as revealed by pile sort data. In addition, the consensus analysis reveals sex-related subgroup agreement in the rankings, but the aggregated rankings of neither men nor women seem to more closely correspond to the harvest data. Overall, these results suggest that a conformist learning bias could allow novice hunters to acquire information that would promote optimizing hunting strategies.

Recent analyses of food sharing in small-scale societies indicate that reciprocal altruism maintains interhousehold food transfers, even among close kin. In this study, matrix-based regression methods are used to test the explanatory power of reciprocal altruism, kin selection, and tolerated scrounging. In a network of 35 households in Nicaragua's Bosawas Reserve, the significant predictors of food sharing include kinship, interhousehold distance, and reciprocity. In particular, resources tend to flow from households with relatively more meat to closely related households with little, as predicted by kin selection. This generalization is especially true of household dyads with mother-offspring relationships, which suggests that studies of food sharing may benefit from distinctions between lineal and collateral kin. Overall, this analysis suggests that exchanges among kin are primarily associated with differences in need, not reciprocity. Finally, although large game is distributed widely, qualitative observations indicate that hunters typically do not relinquish control of the distribution in ways predicted by costly signaling theory.

OBJECTIVES We measured carbon and nitrogen isotopic ratios in a contemporary population, and tested how the isotopic variability relates to measures of socioeconomic status (e.g., household wealth) and anthropometric measures (e.g., standardized height-for-age and weight-for-age z-scores). METHODS Hair samples from individuals living in the Bosawas Biosphere Reserve in Nicaragua were analyzed for δ13 C and δ15 N, and these data were examined in relation to individual (e.g., age, sex, anthropometrics) and household (e.g., household size, wealth) variables. RESULTS We found through mixed-effects modeling that δ13 C and δ15 N varied predictably with individual age and household wealth. δ13 C and δ15 N did not, however, improve models predicting variation in individual anthropometric measures. CONCLUSION These results indicate that, although there is a relationship between diet (δ13 C and δ15 N) and socioeconomic variables, these dietary differences are not the main cause of health differences in this population.

Once absent in much of Amazonia, dogs are now commonly used for hunting throughout the lowland Neotropics. Although some ethnographers have questioned their usefulness, dogs are particularly effective in pursuits of several mammalian prey species. The return rates of hunting with dogs appear to compare favorably with those of hunting with firearms, and dogs may be especially beneficial in anthropogenic habitats. There is considerable cross-cultural variation in the training and care of dogs. Good hunting dogs typically receive better care than their less-talented conspecifics. Mortality rates for dogs in the Neotropics are high, and the causes of death include malnutrition and attacks by other animals. Although isolated Neotropical societies may not have initially recognized the overall value of hunting dogs, a more likely explanation for the absence of dogs in prehistoric Amazonia is the high mortality of dog populations in the region. Additional research is needed to resolve ethnological questions about...

Although dogs are used by subsistence hunters in many locations throughout the world, hunters with dogs have not been studied from an optimal foraging perspective. A study of indigenous Mayangna and Miskito hunters in Nicaragua indicates that the use of dogs affects both the encounter rates and the pursuit times of several prey types. Before hunters can identify the prey type and initiate a pursuit, they must first catch up to the dogs, and their dogs sometimes chase unprofitable prey types. These costs are incorporated as an additional constraint in the optimal prey choice model. The results of the optimal foraging analysis indicate that hunters generally focus on prey types that are in the optimal diet set. However, hunters do not consume two rarely encountered species that are in the optimal diet set, giant anteaters and northern tamanduas. Although hunting with both rifles and dogs increases the likelihood of harvesting tapirs, the return rates of hunting with dogs, hunting with rifles, and hunting wi...

SUMMARYAlthough they are used throughout the Neotropics, the impact of dogs on the composition of wildlife harvests has received little systematic attention. In the Bosawas Biosphere Reserve of Nicaragua, indigenous hunters rely heavily on dogs to locate prey. Hunting harvest data over a year-long period in two indigenous Mayangna and Miskito communities indicate that the use of hunting dogs is significantly associated with the harvests of several terrestrial mammalian species. The use of dogs is also a significant predictor of the extent to which the species composition of harvests deviates from Neotropical averages. Although dogs appear to have little effect on the sex profiles of harvested game species, the use of dogs is significantly associated with hunting in agricultural landscapes. From a conservation perspective, the disadvantages of dogs include their indiscriminate pursuit of prey species, including species that hunters would not otherwise pursue. Advantages of dogs include their relative ineffectiveness in pursuits of species that are particularly vulnerable to overhunting, such as primates and white-lipped peccaries (Tayassu pecari). Hunting dogs may be an economical option for many Neotropical societies, and their role in wildlife management plans merits increased attention from conservationists.

Distributions of human foraging success across age have implications for many aspects of human evolution. Estimating the distribution of foraging returns is complicated by (1) the zero-inflated nature of hunting returns, as many if not most trips fail, and (2) the substantial variation among hunters, independent of age. We develop a multilevel mixture analysis of human foraging data to address these difficulties. Using a previously published 20-year record of hunts by 147 individual Ache hunters in eastern Paraguay, we estimate returns-by-age functions for both hunting failures and the size of harvests, while also estimating the heterogeneity among hunters. Consistent with previous analyses, we find that most hunters peak around 40 years of age. We can also show, however, that much more of the variation among Ache hunters arises from heterogeneity in failure rates (zero returns), not harvest sizes. We also introduce a new R package, glmer2stan, to assist in defining and fitting similar multilevel mixture models.

This report is the first to document giant anteaters (Myrmecophaga tridactyla) in Nicaragua. An indigenous hunter killed four giant anteaters in the Bosawas Biosphere Reserve, Nicaragua. The Mayangna and Miskito residents of the reserve do not eat giant anteaters, but hunters sometimes kill the animals because of the threat they pose to hunting dogs.

In past and modern human societies, dogs have played an important role as hunting companions. Given considerable ethnographic evidence that dogs vary in their hunting abilities, this paper addresses the effects of key demographic variables, namely age and sex, on the amount of harvested game that dogs contribute in an indigenous Nicaraguan community. Controlling for variation in the time spent potentially hunting, male dogs and older dogs are significantly associated with greater harvests. These results may account for documented preferences for males in both archaeological and ethnographic contexts. Among societies in which dogs are used both as hunting companions and sources of food, the age-related delay in peak hunting ability also suggests a tradeoff that might explain the consumption of dogs shortly after they have reached adult size. Informant rankings of two cohorts of dogs indicate that residents of the community exhibit high agreement about the relative abilities of the dogs, and the rankings indicate that dogs from the same household exhibit comparable skill. There is little evidence that talented, highly-ranked dogs are provided a more nutritious diet, as measured by nitrogen-based and carbon-based isotopic analysis of hair samples. Overall, although dogs can be quite advantageous as hunting companions, this research suggests that the heterogeneity of hunting ability combines with the high mortality of dogs to impose risks on households that depend on dogs as a source of harvested meat.