The Behavioral Ecology of Food Sharing among North Siberian Foragers

Buffering and By-Product Cooperation

The 12 cooperative hunts in Ust Avam in which there was no genealogical relatedness between hunt participants and participants' households are significant for the behavioral ecology of hunter-gatherer food transfer. Most of these hunts involve friends going out hunting or fishing together, and dividing meat and fish afterward. A different model should be used to account for this behavior.
One possibility for explaining food sharing during cooperative hunts by non-relatives is the by-product-mutualism model. This model entails cooperative hunting under conditions of environmental adversity and high opportunity costs for not participating in the pursuit (Dugatkin et al. 1992, Mesterton-Gibbons and Dugatkin 1992). There are immediate net positive benefits to the individuals cooperating in the hunt. Defection on cooperative pursuit is not punished, but is to the defector's disadvantage, as foraging efficiency is reduced (Winterhalder 1997). Food sharing under by-product cooperation should occur in cases in which both parties participated in the hunt and not in cases of solitary hunts.

In Ust Avam, and among other human foragers, these cooperative hunts are likely parts of a chain of events. Any given cooperative hunt is a synchronic snapshot of a social relationship. These social relationships more than likely entail transfer of food at other times and situations. Thus, cooperative hunting at certain times may be related to risk reduction at other times.

Risk-buffering models emphasize sharing as a mechanism that reduces variance in daily food intake among cooperating members of a band through delayed returns (Cashdan 1985, Halstead and O'Shea 1989, Smith 1991). By contributing to the subsistence needs of a set of regularly cooperating individuals, buffering strategies are adaptive for individuals in terms of gaining predictable food supplies. Buffering strategies are expected when variance in daily hunting returns is high. The size of the sharing pool should be relatively small and composed of regular cooperators (Wilkinson 1988, Winterhalder 1997). With buffering, returns are delayed. The value of the item being exchanged is what is important, with benefits accruing directly to individuals for cooperation (Trivers 1971, Axelrod and Hamilton 1981, Axelrod 1984). Variance-reduction models make no prediction about the genealogical relatedness of the cooperators.

The Dolgan and Nganasan of Ust Avam spoke to me about two types of faunal and aquatic resources in their environment: local and migratory populations. Local and migratory populations of caribou (Rangifer tarandus sibericus), various species of whitefish and trout, as well as arctic fox were identified. Local populations of prey are widely dispersed, procurement is asynchronous, and the animals are often treated with increased symbolic respect or explicit conservation. Migratory populations are concentrated geographically and temporally. During chronologically compact periods of migration, foraging is characterized by synchronous and cooperative production. As a result, there is a range of predictability (Table 3, Appendix) and efficiency (Table 4, Appendix) for the same prey species. Asynchrony and package-size have been hypothesized as factors in the presence of risk buffering strategies (e.g., Winterhalder 1997, Kaplan and Hill 1985b). In Ust Avam, food sharing during periods of asynchronous production of large packages should take on the characteristics of buffering reciprocity, a concept explicitly used at times (vzaimno-obratnaia pomoshch, or mutual return aid). This project will span several seasons of foraging for local resources and foraging for migratory resources. By covering multiple seasons of local and migratory resource acquisition, as well as seasons when storage is possible and seasons when it is not, this project will significantly advance the available data on the role of synchrony and seasonality in cooperative resource production and transfer. One possibility to be investigated is that by-product cooperation occurs during migration periods and buffering occurs during periods of asynchronous acquisition.

Value Transfer

In Ust Avam, Dolgan and Nganasan told me that they distribute meat and fish according to the maxim "Give it, if you have it." Translated into behavioral-ecological terms, the transfer of a portion of a food resource increases the collective value of the resource. Marginal value means that people are sharing because they are giving away portions that have little value to them but great value to others. Higher quantities on hand should correlate with larger amounts or more frequent giving. Lower quantities on hand should correlate with less frequent or smaller gifts. Specific costs, such as household location, should affect amounts transferred and frequency of transfers under the marginal-value considerations. Knowledge of amounts on hand and relative household need are more easily assessed between households living in close proximity.

Marginal valuation does not necessarily exclude the possibility of altruistic resource transfer and buffering hypotheses. However, under altruistic resource transfer, marginal-value considerations should be weaker than in buffering transfer, especially in cases of resource transfer to kin. The exception should be in cases in which altruistic transfers are made to non-relatives. Among many hunting-and-gathering peoples, the ethic of meat sharing is argued to be part of hunters' reciprocal relationship with the prey species (Hallowell 1960, Fienup-Riordan 1990, Bird-David 1992, Nuttal 1992). In this literature, animals are considered non-human persons that must be treated in the correct way, which includes distribution to non-related people in the community. It is said that this distribution contributes to good future hunting, since the animal is perceived to be giving itself up to the hunter and will only do so if it is cared for by means of ritual and sharing. In other terms, this may be thought of as providing public goods. It is likely that such public goods provisioning operates under marginal valuation (Winterhalder 1997). In Ust Avam, previous survey research (Table 1, Appendix) revealed that people shared food with pensioners, single mothers, and other people who ask. These people are neither friends nor relatives, and amounts on hand should be the major consideration if marginal valuation is an influential consideration.

Because very large meat packages are rarely procured in Ust Avam and there are no public distributions, it is unlikely that distribution to nonrelatives is a kind of public show of hunting prowess to increase status. It is likely, however, that some meat and fish provisioning to nonrelatives is conducted in anticipation of sexual access. This type of transfer might be considered part of mating effort and cost-benefit measurements may be difficult to make because the return is in a different currency. Another similar type of value transfer is trade for another commodity of value. In the case of trade, transfer of meat or fish should provide a return in goods or services of higher value to the giver. In testing the value-transfer model, the objective is to determine the extent to which quantities of food on hand can explain the variance in observed resource transfer for altruistic resource transfer, buffering, and any other social contexts, such as public provisioning, mating effort, or trade.