Recent years have seen a shift from expert-driven methods for biodiversity conservation to more participatory community-based approaches. While the former - and by far dominant position - propagates a policy of spatial zoning based on the view that local people constitute the main threat to nature, the latter approach suggests that local communities may be allies in the struggle to conserve biodiversity. This study analyses this debate on the basis of the GEF-funded Bismarck-Ramu integrated conservation and development program in Papua New Guinea. By giving a detailed description of the interactions between the project team and local people, the author discloses some of the implicit assumptions on which such interventions are based. Local people however, seldom fit the stereotypical images that outsiders impose on them. Instead, they tend to enrol such interventions in a variety of personal and collective endeavours. This study for example, argues that the establishment of a conservation area by a number of Ramu communities should not be attributed to the existence of an indigenous conservation ethic, but was in the first place based on the wish to maintain control over land and resources in the face of incoming migrants. The disparate motives and priorities that underpin the co-operative arrangements between conservation projects and local people attest to their fragility.