Impacts of oil palm plantations expansion on the distribution of terrestrial mammals in South-East Asia

The recent expansion of oil palm plantations in Southeast Asia has caused significant range loss for many species. We examined the impact of this expansion on mammal distribution in Indonesia, Malaysia, and Thailand. Using historical range maps (1970–1980 s) and satellite imagery of oil palm plantations (1981 to 2017), we quantified the extent of species’ lost and retained ranges occupied by oil palm plantations before and after 1990. The siamang (+ 23%), tiger (+ 11%), and large-spotted civet (+ 10%) were the most impacted, experiencing plantations’ expansion in the lost range. All species, including endemic ones, have also seen an increase in plantations’ extension within their current ranges. Additionally, we found a significant correlation between the amount of range lost and the area occupied by plantations after 1990. Our findings underscore the urgent need for sustainable land management and conservation strategies to mitigate the adverse effects of agricultural expansion on biodiversity.