Land use legacies shape wild boar (Sus scrofa) diet along a forest-urban gradient in Singapore

Source abstract

Wild boar ( Sus scrofa ) are one of the most widespread mammals on the planet but when overabundant, can cause negative impacts to ecosystems and people. In Singapore, native wild boar were extirpated in the mid-1900s amid rapid habitat loss and hunting, but have since re-established populations naturally and are now highly abundant in local forests where their natural predators remain absent. Understanding the role that their dietary preferences play in their ecological success is thus crucial for managing their populations and human-wildlife conflict in the compact city state. Using DNA metabarcoding of faecal samples, we show that local wild boar exhibit a high degree of dietary flexibility. While there is a high prevalence of soil invertebrates and native plant foods in our samples, a wide variety of cultivated fruit tree species – common remnants of past land use in secondary forests – was also detected. However, the extent of neighbouring vegetated areas was not strongly or consistently correlated with plant and animal dietary diversity or composition. Our study suggests that food resources due to land use legacies and other anthropogenic food sources may play a role in subsidising local wild boar populations, but likely vary spatiotemporally. Management of remnant cultivated tree species in secondary forests can be a potential strategy for regulating wild boar population in the highly urban forests of Singapore, but further quantitative research on the availability and exploitation of anthropogenic foods, and their demographic consequences, will be needed to evaluate the effectiveness of such interventions.