Introduction

Given the rapid loss of tropical forests (Achard et al. 2002) and the probable consequent extinction of native biotas (Sodhi et al. 2004a), protected areas (PAs) are pivotal for the conservation of remaining biodiversity (Rodrigues et al. 2004). However, the disappearance and degradation of tropical forests both within and outside the borders of PAs (e.g. commercial logging and agricultural encroachment; Curran et al. 2004), continues to undermine their ecological value (Liu et al. 2001). It is therefore important to determine the conservation value and underpinnings of resource harvesting in PAs.

Apparent conflicts between conservation and development could possibly have been avoided if biological and social knowledge were considered during land-use planning, including the design of PA networks (Terborgh et al. 2002; but see Kremen et al. 1999). Poor ecological and sociological data are impeding conservation efforts in Southeast Asia (Sodhi et al. 2004b). Southeast Asian biotas harbour high proportions of endemism (Myers et al. 2000) and the region is expected to suffer a loss of up to 21% of its biodiversity by 2100 if present deforestation rates continue (Brook et al. 2003). The Indonesian island of Sulawesi has extraordinary levels of endemic fauna (e.g. 61% and 34% of mammals and birds are endemic, respectively) and is experiencing both intensive human encroachment pressure in PAs and high deforestation rates (Sodhi & Brook 2006). Much of this negative impact, in part, stems from human resettlement close to the PA fringes as part of a nationwide transmigration project (Whitten et al. 2002).