Jeremy Koster

Hunting with Dogs in Nicaragua : An Optimal Foraging Approach

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 with both guns and dogs are otherwise comparable. This study therefore demonstrates that dogs can be valuable hunting accessories.

The impact of hunting with dogs on wildlife harvests in the Bosawas Reserve, Nicaragua

SUMMARY Although 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.

Interhousehold Meat Sharing among Mayangna and Miskito Horticulturalists in Nicaragua

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.

Living with Kin in Lowland Horticultural Societies

Postmarital residence patterns in traditional human societies figure prominently in models of hominid social evolution with arguments for patrilocal human bands similar in structure to female-dispersal systems in other African apes. However, considerable flexibility in hunter-gatherer cultures has led to their characterization as primarily multilocal. Horticulturalists are associated with larger, more sedentary social groups with more political inequality and intergroup conflict and may therefore provide additional insights into evolved human social structures. We analyze coresidence patterns of primary kin for 34 New World horticultural societies (6,833 adults living in 243 residential groupings) to show more uxorilocality (women live with more kin) than found for hunter-gatherers. Our findings further point to the uniqueness of human social structures and to considerable variation that is not fully described by traditional postmarital residence typologies. Sex biases in coresident kin can vary according to the scale of analysis (household vs. house cluster vs. village) and change across the life span, with women often living with more kin later in life. Headmen in large villages live with more close kin, primarily siblings, than do nonheadmen. Importantly, human marriage exchange and residence patterns create meta-group social structures, with alliances extending across multiple villages often united in competition against other large alliances at scales unparalleled by other species.

Hunting Dogs in the Lowland Neotropics

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 the use of dogs in the lowland Neotropics.

Food sharing networks in lowland Nicaragua: An application of the social relations model to count data

Abstract Previous research on food sharing in small-scale societies provides support for multiple evolutionary hypotheses, but evolutionary anthropologists have devoted relatively little attention to the broader relational context of inter-household transfers of food. The present research observes transfers of meat over a yearlong period among 25 households of indigenous Mayangna and Miskito horticulturalists in Nicaragua. To analyze these data, we extend the multilevel formulation of the social relations model to count data, namely the number of portions of meat exchanged between households. Along with other covariates, we examine the effect of an “association index,” which reflects the amount of time that households interact with one another. The association index exhibits a positive effect on sharing, and our overall results indicate that food sharing networks largely correspond to kin-based networks of social interaction, suggesting that food sharing is embedded in broader social relationships between households. We discuss possible extensions of our methodological approach, as appropriate for research on food sharing and social network analysis more broadly.

Giant Anteaters (Myrmecophaga tridactyla) Killed By Hunters With Dogs In the Bosawas Biosphere Reserve, Nicaragua

Abstract 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.

Heterogeneity of hunting ability and nutritional status among domestic dogs in lowland Nicaragua

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.

SOURCES OF STABLE ISOTOPE VARIATION IN ARCHAEOLOGICAL DOG REMAINS

Assessment of the δ 15N ratios and δ 13C isotope values of archaeological dog and human bone collagen, ethnoarchaeological dog bone collagen, and ethnoarchaeological dog and human hair protein demonstrates that these tissues can be used to show subtle differences in diet between households at the same site. While δ 13C isotope values for dog and human bone and hair protein can be used as evidence of C4 photosynthetic plant foods, it is not necessarily an accurate measure for the presence or absence of maize in the diet. Less than 50% of the ethnoarchaeological dog and human samples from households that consumed an average of 0.01 kg of maize per day, had δ 13C isotope values greater than −19%.

Wisdom of the Elders?: Ethnobiological Knowledge across the Lifespan

A common assumption is that individuals continue to accumulate ethnobiological knowledge throughout their lives, resulting in greater expertise among the elder generations. Alternative theoretical perspectives suggest that ethnobiological knowledge about animals should peak earlier in life, paralleling and facilitating the emergence of foraging proficiency among younger adults. We test these competing models among indigenous Nicaraguans with three measures of knowledge about fish behavior. Our results indicate that individuals exhibit considerable domain knowledge as relatively young adults. There is also a positive correlation between some measures of knowledge and fishing ability, suggesting that knowledge may promote and develop from specialization and the allocation of effort to fishing. These results imply a model of humans as flexible learners, assimilating ethnobiological knowledge via social learning and related experiences. Contrary to conventional perspectives, we suggest that age-related variation in knowledge among adults is attributable primarily to proximate factors, such as acculturation, time allocation to related productive tasks, and social-learning opportunities.