hese changes include a rapid rate of population growth among the Penan since the 1960s. as their region has become more accessible to medical facilities and there arose competition for food resources with other tribal groups who also began to expand into the interior as their population increased.
Moreover, the Penan themselves moved downriver and, as they settled and adopted farming, the unit of production changed from being largely communal to one now based on the household. An important consequence of this settlement is the competition for food resources even among the members of each community. This is because many modern-day Penan males are actively engaged in cashearning activities; thus, limiting the period in a year allocated for food production. This has caused considerable pressure on the limited stock of sago palm as each farmer tries to produce as much as possible during the short period set aside. As with other, and earlier, blockades of timber roads, the Penan defence of their actions is as much related to a desire to obtain a larger share in the benefits, as it is to preservation of the forest.
The case of the Penan is not an isolated example. Fujisaka (1986: 4) identified similar trends among some tribal communities in the Philippines; for example, among his main findings, he notes that 'increasing competition for resources within and among groups and greater pressures on resources and ecosystems sustainability accompany the population increases'.
There are many other internal changes which have significant impact on the traditional food resources of the Penan. The gradual depletion of traditional food sources is, to some extent, the result of transformations within the society- the result of changing needs and aspirations. The above findings directly question the model which calls for the deployment of the traditional social and economic systems as the means to safeguard the society and to provide it with a sustainable form of livelihood. If the proposal is interpreted largely within the narrow perspective of their old production system, it is clear that it will not solve the economic problems that are currently faced in the early 1990s.
The sustainability of the old system rests on following very rigid prescriptions: namely, a small population and low population growth; high land-man ratio; and a nomadic lifestyle. In 1990, over 95 per cent of the Penan had settled down. Present-day Penan, especially the younger generation, are not interested in their traditional way of life for various reasons. As Langub (1990) observed, it is only the older generation who still cherish the traditional way of life. The younger generation has been too deeply encapsulated into the modern economy to be able to survive under the traditional systems.
Clearly, therefore, the ability of the traditional system to sustain the Penan culturally, socially, economically and environmentally into the twenty-first century is highly questionable. The cost of not injecting some elements of the modern social and economic systems and development into Penan society could be disastrous in the long run. This does not deny the fact that certain aspects of the tribal culture can be used as a guide towards a more sustainable form of social and economic development. As Lian (1987) has argued in regard to the development strategy of the Kenyah, the better path is to build on an existing foundation instead of adopting a totally new form of social and economic structure, and to direct cash-earning activities towards a specific socioeconomic objective. In this way, there is hope of reducing the degree of 'economic shock' when a particular type of cash-earning activity comes to an end. In the case of the approaching end of the timber industry, Lian (1987: 199-200) concludes:
There is no doubt that living standards will drop. First to go will be items like the television sets, now commonly owned ... where it is possible to receive television transmission. Except for those with electric generators, most of the refrigerators too will be useless. Shortag