Synanthropic survival: low-impact agriculture and White-shouldered Ibis conservation ecology
The conservation value of traditional agriculture is well recognised in Europe, where retention and restoration of farming practices that support open-habitat species is a standard management technique. Elsewhere, however, this value is often overlooked while conservation attention is directed at natural habitats and forest biota. This thesis assesses the importance of traditional farming for developing-world biodiversity, using the White-shouldered Ibis Pseudibis davisoni in Cambodia to investigate practices underpinning synanthropic relationships, links between farming-dependent species and local livelihoods, and potential conservation strategies. Ibis status and ecology was investigated by censuses, foraging observations, prey sampling, experimental exclusion of grazing and burning at foraging habitats, and experimental protection of nests. Livelihoods were assessed by social research methods including household income surveys. A literature review found a subset of threatened bird taxa now dependent on traditional farming following the loss of natural processes. Agricultural change, driven by external agribusiness and intrinsic livelihood modernisation, endangers these species, including the ibis. Ibis foraging ecology is closely associated with local livelihood practices, with favoured dry forest habitats created or maintained by domestic livestock grazing, anthropogenic fire and rice cultivation. Not all local practices are beneficial, however: ibis nests are exploited for food by local people, and nest guardians do not improve nest success (although this requires further testing). White-shouldered Ibis’s breeding season contrasts with that of the sympatric Giant Ibis Thaumatibis gigantea, most likely explained by the former’s dry-season-adapted foraging strategy. Household incomes and livestock capital assets demonstrated that local people share a dependence on the livelihood practices and dry forest landscape supporting the ibis. Nevertheless, local livelihood change (such as mechanisation) may uncouple this linkage, making a potential win-win conservation strategy unviable. Conservation must develop measures to maintain valuable farming practices before they, and the species dependent on them, are lost through agricultural transition.
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