Possible extinctions of dung beetles (Coleoptera: Scarabaeidae) in Bukit Timah Nature Reserve, Singapore

Bukit Timah Nature Reserve (BTNR) contains the largest patch (71 ha) of primary rainforest left in Singapore after approximately 95% deforestation by humans over the last century. Floral and faunal diversity have been monitored by the colonial British natural historians and local nature enthusiasts. This information can be used to determine biotic turnover due to deforestation as there is little information available on this subject. We examined dung beetle species collected in the Bukit Timah Nature Reserve from the 1960s to 1970s and compared them with species collected from the same forest patch today. We employed two trapping methods - baited pitfall traps and flight interception traps for our survey. Out of the nine species collected from the past, three species - Cartharsius molossus, Onthophagus deliensis and Ont. cf mentaveiensis may be extinct. One of these species, Cartharsius molossus, a large-bodied dung beetle, plays an important role in nutrient recycling in the forest ecosystem. The possible extinctions of dung beetles within a span of 30 years in BTNR highlights the recurring events of species loss in Southeast Asian forests today and the need to preserve whatever remaining refuges of biodiversity.