potential for sustainable harvests by traditional Wana Hunters in Morowali Nature Reserve, Central Sulawesi, Indonesia, The

Human Organization, Winter 2000 by Alvard, Michael S

Conflicts arise between subsistence hunters and those who wish to conserve the animals they hunt. Solutions require measures of sustainability. Data are presented on the sustainability for the Wana hunters living in the highlands of Central Sulawesi, Indonesia. Pigs (Sus celebensis) and dwarf buffalo (Bubalus spp.) account for 58 percent and 40 percent of the large game harvest by weight. Primates (Macaca tonkeana) are occasionally killed. Data suggest pig hunting is sustainable, primates may have been overhunted in the past, and that dwarf buffalo are vulnerable. Using GPS, the area encompassing all of fields, traps, and house locations for the sample of 153 Wana was measured to be only 18.1 km^sup 2^. To sustain their current harvest of pigs, however, the Wana need access to at least 290km^sup 2^ of catchment. Their harvest of 0.30 pigs per person per year can be sustained if the Wana population density is no greater than 0.53 persons per km^sup 2^. Pigs are the most sustainable of the Wana's prey options. Removing primates from the Wana's diet would have a negligible nutritional effect. Persuading Wana hunters not to pursue dwarf buffalo will be the most difficult challenge for Morowali's managers.

Key words: human ecology, hunting, sustainable use, Wana, Indonesia

Anthropologists and others have increased their attention on how native inhabitants of rain forests use game resources (e.g. Peres 1994; Robinson and Bennett 2000; Robinson and Bodmer 1999; Stearman 1990; Stearman and Redford 1995; Wadley et al.1997; Wilkie et al. 1998). This focus is, in part, a result of the desire to learn how to conserve biodiversity while at the same time recognize and sustain this valuable economic resource for rain forest inhabitants. A number of conclusions have emerged from this research. The first is that prey species are highly valued and nutritionally important resources for many subsistence people living in rain forests (Caldecott 1988; Martin 1983; Redford and Robinson 1987). For example, Caldecott (1988) estimated that in rural Sarawak, Malaysia, approximately 9 million kilograms of game are consumed each year. Replacing this game via domestic pig production would cost 112 million Malaysian dollars. The second conclusion is that subsistence hunters can sometimes overexploit their prey species (Redford 1991). For example, Bodmer (1994) found that subsistence hunters in the Tamshiyacu-Tahuayo Reserve in the rainforests of northeastern Peru were overhunting large primate species and tapir. I came to the same conclusions for Piro Indians, subsistence hunters in Amazonian Peru (Alvard et al. 1997). Third, although subsistence hunters are unlikely to conserve their prey for a variety of reasons (Alvard 1998), overhunting is not inevitable. Often the same studies that show evidence for overexploitation do so only for a limited number of the total prey species hunted. That is, some species are hunted sustainably while others are not. For example, Bodmer (1994) found that the hunters in the Tamshiyacu-Tahuayo Reserve were hunting collared peccaries and deer sustainably (see also Fitzgibbon et al. 1995; Vickers 1988, 1991).

These results are encouraging because they suggest it is possible to maintain acceptable levels of biodiversity while at the same time allow subsistence hunters to derive value and subsistence from the forests. Recent work has focused on determining those species most vulnerable to overharvest, and thus in need of protection, and those species that are good candidates as sustainable hunted resources (e.g., Bodmer et al. 1988; Fitzgibbon 1998). A sustainable harvest is one that can be removed from a prey population on a regular basis without depleting the source population. Goodland (1995:10) refers to environmental sustainability as "maintenance of natural capital." As Hilborne et al. (1995) note, sustainable harvesting ultimately depends on reproductive surplus in the target population. Organisms can produce more offspring than required to maintain their populations; hunters can harvest the surplus in a sustainable manner. Such definitions allow a quantitative estimate of sustainable harvest size to be calculated.1

It is critical however, to have a clear understanding of what constitutes a sustainable harvest. Sustainable yield estimates are usually presented in terms of the number of animals or kilograms of meat that hunters can sustainably harvest per unit catchment area (Robinson and Redford 1994, 1991). It is not surprising that the sustainability of a community's hunting economy can depend critically on the amount of land from which it takes its prey. A harvest that is unsustainable when removed from 10km^sup 2^ of forest may be easily sustained when it is removed from 100 kml.

I report here on land use and sustainable hunting for the Wana, traditional hunter-horticulturalists who live in the uplands of Central Sulawesi, Indonesia, within Morowali Nature Reserve. Using a method developed by Robinson and Redford (1991), I estimate the number of prey that can be harvested sustainably per square kilometer for the important Wana species. I use prey census data to measure hunting impact, provide estimates of the size catchment area from which the Wana are culling their prey, and estimate the Wana population density compatible with a sustainable harvest of pigs, their most important prey species. I conclude by discussing limitations to the model and, briefly, the future of Wana hunting in Morowali.