A wild boar appears in the subway tunnel of metro Line 1 in Nanjing, East China’s Jiangsu Province, on November 28, 2024, causing train delays in both directions. Photo: CCTV

Metro operators in Nanjing, East China’s Jiangsu Province, have initiated an investigation into a wild boar incident in the city’s subway tunnel that has caused subway delays and raised public concerns. Experts attribute the recent events caused by boars in 26 provinces to improved environmental conditions and a reduction in the population of boars' natural predators.

Some passengers reported that a wild boar was spotted in the tunnel between Tianlongsi Station and Andemen Station on metro Line 1 in Nanjing on Thursday night, causing train delays in both directions, China Central Television’s (CCTV) reported on its official WeChat account on Sunday. 

In response, staff from the Nanjing metro operators confirmed the incident and stated that the specifics are still under investigation.

Wild boars are omnivorous animals with diverse diets and aggressive temperaments. In recent months, as wild boars have been venturing down the mountains more frequently in search of food, incidents of wild boars entering residential homes and even injuring human beings have been reported in various regions.

According to incomplete statistics, more than 10 wild boar-related incidents have resulted in seven casualties since October, Beijing News reported Friday. 

On November 24, a wild boar fatally attacked a 76-year-old woman in a village in Langao county, Northwest China’s Shaanxi Province, when it was chased by a hunting dog. Before the tragedy, some villagers had released hunting dogs to track down wild boars that had severely damaged local crops. 

On October 25, a wild boar entered a roadside shop in Hangzhou, East China’s Zhejiang Province while another wild boar attacked a man at a car repair shop in Nanchang, East China’s Jiangxi Province. 

On October 27, a wild boar entered the high-speed railway connecting line between Nanjing South Railway Station and Zijinshan East Station, colliding with a passing train, leading to equipment failure and the suspension of railway operations. On the same day, an injured wild boar entered a resident’s bedroom in Miaofengshan town in Mentougou district, Beijing. 

With the continuous improvement of the ecological environment in China, the population of wild boars has been increasing rapidly, CCTV reported, citing data released by the National Forestry and Grassland Administration in January that wild boars with an estimated population of 2 million spread across 28 provinces, among which 26 provinces have reported harming incidents involving wild boars. According to the administration, wild boars no longer face a threat to their survival, and in many provinces, their numbers are excessively high, disrupting local production and daily life, prompting calls for population control measures. 

According to Hu Defu, a professor from the School of Ecology and Nature Conservation, Beijing Forestry University, the populations of tigers and leopards have significantly decreased in recent years, resulting in a decline in natural predators that help regulate wild boar populations. Wild boars are thriving due to their high reproductive rate and adaptability to diverse environments. As winter approaches, their food intake increases, driving them to widen their foraging areas. 

China updated the list of terrestrial wild animals of important ecological, scientific and social value in 2023, which saw the removal of wild boars that no longer face threats to their survival as a species, according to Xinhua News Agency.

Even if wild boars are removed from the list, existing laws still do not permit arbitrary hunting of the species. While illegal hunting still exists, if legal hunting is liberalized, it would further exacerbate the challenges to the protection of wild boars and other wild animals, Sun Quanhui, a scientist from the World Animal Protection organization, told the Global Times on Sunday. 

According to Sun，an excessive number of wild boars exceeding the environment’s carrying capacity can cause harm to vegetation and ecosystems, damage farmland, resulting in reduced crop yields, and disease spreading. 

In the absence of natural predators, artificial hunting is a means of wild animal population control. Meanwhile, since wild boars are an integral part of the ecosystem, hunting plans must be scientifically assessed in advance, and hunting activities must be strictly regulated to minimize adverse impacts on other wildlife and the production and livelihoods of nearby communities, Sun said. 

Fifteen departments, including the National Forestry and Grassland Administration, jointly issued a work plan for preventing and controlling damages caused by wild boars and other wildlife animals in January, which outlined tiered population control measures and the creation of specialized wildlife management organizations.

According to Zhang Minghai, a professor from the College of Wildlife and Protected Area, Northeast Forestry University, wildlife population management requires surveys of local wild boar populations to monitor annual population and habitat changes. Establishing reasonable hunting quotas and implementing proactive measures to mitigate damages caused by wild boars is essential, while further improving the compensation policy for damages caused by wild boars. 

Over the long term, only by restoring the natural populations of wild boars' predators, appropriately expanding their habitat range, and continuously adjusting human production and development methods to maintain ecological balance, can the issues caused by the increasing wild boar be effectively addressed, Sun said. 

In addition, experts reminded that wild boars have strong attacking power, particularly during the breeding season or when startled, making encounters especially dangerous. If encountering a wild boar, it is advisable to distance yourself immediately. 

Hu reminded the public to stay calm and avoid panicking when encountering a boar, and seek nearby obstacles for protection. Then, slowly retreat to maintain a safe distance. Hu noted that dawn and dusk are peak activity times for wild boars.