Population Expansion through Warfare
We would now discuss the contribution of A.P. Vayda towards the application of ecosystem approach in anthropology. Vayda pioneered a very interesting area of ecological research in his famous paper ‘Expansion and warfare among swidden agriculturalists’ published in American Anthropologist as early as 1961 (Vayda, 1961: 346-58). In that paper he began by questioning the standard anthropological interpretation of warfare among simple societies as expression of ‘social solidarity’ or as a ‘safety-valve institution’ for the release of pent-up aggressions. By using the ethnographic literature and other archival sources, Vayda presented two case studies of warfare among the Maoris of New Zealand and Ibans of Sarawak in which he explained the process of expansion of populations in a purely ecological framework. According to Vayda, the need for expansion of these tribal communities arose from the practice of slash-and-burn agriculture which involved clearing of forests for agriculture and keeping large amount of land as fallow for some years before they are again ready for cultivation. Warfare among the Maoris took place for capturing land which has already been cleared by other groups. Vayda argued:
“…Maori groups needing more land may have preferred getting previously used land from other groups, by force if necessary, rather than expanding into the virgin rain forest. If the time and effort required for clearing virgin land were considerably more than were necessary for the operations of both conquest and the preparation of previously used land for cultivation, it follows that territorial conquests, such as some of those recorded in Maori traditional history, would have added more efficiently to the prosperity of particular groups than would peaceful dispersion(Ibid)”.
Vayda extended the above line of argument to envisage Maori intra-tribal warfare in the form of a ‘chain reaction’ model in which the expansion of one group into the contiguous territory of the second group led the second to the territory of the third and so on until the last group in the chain had to take the trouble to clear the virgin forest for survival. In the second model, Vayda analyzed the expansion of the Ibans of Sarawak in Indonesia. In contrast to Maoris, the Ibans displayed remarkable mobility over geographical space and lesser frequency of intra-tribal warfare; the Ibans however, were found to be engaged in warfare with other tribes. According to Vayda, the expansion of the Ibans took place through a variety of environmental and socioeconomic factors. The Ibans expanded into the riverside lands of the other tribes which facilitated intra-community movements among them. This kind of expansion enabled the Ibans to cooperate more effectively in military undertakings and also provided the tribe access to trading with Chinese and Malay businessmen from whom they got a variety of goods including guns and European iron and steel which further strengthened their economic and military power over a wider territory.
Resource Management through Religious Ritual
In this subsection, we would discuss one of the most remarkable contributions in Ecological Anthropology which employed the conceptual tools of ecosystem to explain the role of rituals among the Tsembaga Marings of New Guinea Islands. In this work Rappaport described the culture of the Tsembaga as a system in which a particular religious ritual functioned to maintain equilibrium between humans and their subsistence resources. Rappaport viewed the relations of the Tsembaga with their environment as a complex system composed of two subsystems, viz.(i) a local subsystem which is constituted by the Tsembaga cultural practices and the immediate nonhuman components of the environment and (ii) a larger regional subsystem of which Tsembaga is one of the constituent units. A lot of quantitative data on calorie consumption, protein intake as well as number of domestic animal over time were collected by Rappaport. The major finding of the study is quite interesting. The Tsembaga mainly subsist on horticulture along with domestication of pigs. Normally, the pig population served a number of functions to the horticulture gardens and the household economy of the tribe and they did not eat pork frequently. Rappaport through his meticulous collection and analysis of field data observed that the increase in the pig population among the Tesmbaga created a stress in the system and the pig began to compete with the human population at the local level. When the stress crossed the threshold of the system, the members of the village community performed a ritual addressed to their ancestors in which large numbers of domestic pigs were slaughtered and the pork was eaten as well as distributed among the kins and allies who helped a particular group in warfare and various economic activities. This pig slaughter ritual reduced the stress in the system and also supplied essential protein to the community members, enhanced social solidarity among kins and allies brought back equilibrium in the system by reducing the pig population to much below the threshold of stress.
We quote from Rappaport: ….. the operation of ritual among the Tsembaga and other Maring helps to maintain an undegraded environment, limits fighting to frequencies which do not endanger the existence of the regional population, adjusts man-land ratio, facilitates trade, distributes local surpluses of pig throughout the regional population in the form of pork, and assures people of high quality protein when they are most in need of it. (Rappaport 1967: 17-30).
The work of Rappaport on the ritual regulation of environmental relations is regarded as one of the most important contributions in the field of Ecological Studies in Anthropology in which we find the application of ecosystem approach in a sophisticated manner and it became very popular in Anthropology and other disciplines during the 1960s and 70s.