Wild boars are considered one of the world's most "problematic species" and "worst invasive alien species" outside their native range. Their populations are increasing rapidly worldwide owing to their exceptional reproductive strategies and ecological adaptability. In China, escalating human–boar conflicts have prompted substantial government investment in population-control measures. However, culling based solely on perceived conflict may carry unintended ecological risks.
In a study published in Biological Conservation, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences showed that although wild boar abundance is linked to increased crop damage, these controversial animals may also play a crucial role in supporting biodiversity and ecosystem stability in tropical forests.
The researchers explored how to balance human-wildlife conflict mitigation and ecosystem function maintenance in wild boar (Sus scrofa) population management. They integrated large-scale crop-damage records with camera-trap surveys at 540 sites in the tropical forests of Xishuangbanna, focusing on native medium- and large-sized terrestrial vertebrates. They examined whether higher wild boar abundance was linked to greater crop damage, reduced habitat use by other vertebrates, and lower community richness or network stability.
The results showed that areas with higher wild boar abundance experienced severe agricultural losses, particularly to maize, but also revealed unexpected ecological benefits. These areas supported greater species richness and more stable ecological networks. Wild boars appear to function as ecosystem engineers, creating microhabitats that benefit other species through their rooting and wallowing behaviors.
The researchers also found that many species adjusted their activity patterns in space and time. As wild boar abundance increased, 21 of 35 species showed greater divergence in diel activity patterns from wild boars, and 23 of 35 species exhibited temporary avoidance.
Therefore, culling based solely on conflict intensity may pose ecological risks, such as reducing local biodiversity and disrupting the stability of species coexistence networks.
"Relying solely on conflict intensity to guide population control decisions risks unintended ecological consequences. Our findings underscore the need to integrate ecological function assessments into management strategies," said QUAN Ruichang of XTBG.
The researchers call for a shift from “conflict-driven control” to evidence-based ecological management. Specifically, they recommend maintaining moderate-to-high wild boar densities in core forest areas so that wild boars can continue to perform their ecological engineering functions. They also suggest using non-lethal preventive measures, such as fencing and repellents, along farmland edges. In addition, long-term monitoring systems should be established so that management thresholds can be adjusted dynamically.
Camera-trap images illustrate potential facilitative interactions between sympatric vertebrates and wild boar.(Image by XTBG)
