Hidden toll on urban wildlife revealed

A herd of Tibetan antelopes crosses the Qinghai-Xizang Highway on Aug 4. (Huang Lunbin/China News Service)

A forum dedicated to roadkill research was held earlier this month in Nanjing, capital of East China's Jiangsu province, attracting academics and experts from across the country to discuss how scientific data gathered from the field can be translated into actionable public policy.

The Forum on Road Safety and Wildlife Conservation was held at Nanjing University's Xianlin campus on Dec 14, and was the culmination of research led by Professor Li Zhongqiu at the university's School of Life Sciences.

The event drew over 60 representatives from 19 universities and research institutes, as well as several environmental and science communication organizations.

It wasn't until the past five years that research into urban roadkill in China really began to gather steam, spearheaded by Li and a team of students and citizen scientists.

It began in 2020 when Li was driving his son to school and spotted a Siberian weasel crossing a street near the university's Xianlin campus. On his return journey, he was dismayed to discover the weasel's still-warm, lifeless body. Struck by the scene, he stopped to document the incident with photos.

This experience opened Li's eyes to the prevalence of roadkill in the megacity of Nanjing.

Despite its frequency, he realized that there was a significant lack of research on the subject within China. Motivated by the gap, Li decided to lead his research team, focused on animal behavior and conservation, in conducting a comprehensive survey of roadkill incidents in Nanjing in 2021. Their efforts culminated in the publication of China's first research paper on urban roadkill in November 2023.

"We planned to expand our research scope, but we quickly recognized our limitations in terms of manpower and data," Li said."This led us to seek support through citizen science."

In late 2023, Li and his team launched a mini-program on the social messaging app WeChat to crowdsource data from the public. In the past two years the initiative has garnered over 8,000 roadkill reports from more than 2,000 contributors nationwide.

By studying roadkill, scientists are able to not only monitor biodiversity and populations, but also identify at-risk species and identify mitigation strategies such as wildlife overpasses, underpasses or biofences.

Wildlife threat discussed

The forum began with a presentation by Li on the establishment and progress of the China Roadkill Monitoring Network, where he highlighted the significant accomplishments of the project in recent years. According to the scholar, roadkill is one of the three major threats to wildlife globally, with an estimated upper limit of 340 million birds killed annually on roads in the United States, according to a 2014 study published in The Journal of Wildlife Management.

During their research on the roadkill situation in Nanjing from November 2020 to October 2021, Li and his team conducted 26 monitoring campaigns across 224.27 kilometers of road, covering a total of 5,831 km over the research period. The team focused on nine roads, which were monitored biweekly throughout the year. They recorded 293 roadkill carcasses across 22 species, of which 284 were identifiable. A total of 136 were mammals, 143 were birds and five were reptiles.

Utilizing mathematical models, Li and his team estimated that annually about 115,000 wild and stray mammals and 456,000 birds are killed on roads in Nanjing.

"Although we lack sufficient data to estimate roadkill figures for the entire country, it is reasonable to assume that the number of birds killed on roads could exceed 200 million," he said.

Li acknowledged that while the roadkill issue is important, it is often underestimated.

"Through our research, we aim to provide an accurate estimation of the roadkill situation nationwide,"Li said. "With a correct estimation, we can raise public awareness about the significance of this issue."

Li highlighted the essential role of public participation in the roadkill project, underscoring its impact on the project's success. As of September, the mini-program used for the project had recorded roadkill incidents involving 800 wildlife species. This included 16 species under the country's first-level protection and some 100 species under second-level protection.

One notable example he shared was the Indochinese box turtle, a critically endangered species. It had not been observed in the wild for many years until a photo of its carcass was uploaded to the mini-program. "This discovery prompted some researchers to request the location of the roadkill so they could investigate further and potentially search for the turtle in the wild," he said.

He said the project also serves as an excellent opportunity to enhance environmental awareness. "Our work offers the public a valuable chance to engage in a citizen science project," he said. "With increased public involvement, we hope to bring together individuals from various fields to collaboratively address this problem."

Xu Feng, an associate researcher at the Xinjiang Institute of Ecology and Geography at the Chinese Academy of Sciences, shared his insights on the complex interactions and adaptations between humans, roads and wildlife. His discussion highlighted important considerations for road safety and animal protection.

Based in Urumqi, Xinjiang Uygur autonomous region, Xu said that the region's road network expanded to 230,000 km last year, with one-third of them constructed since 2021. His research examined the impact of several desert highways on the Xinjiang ground jay, a species unique to the arid landscapes of Xinjiang.

Xu discovered that these rare birds are increasingly drawn to highways, attracted by the availability of food and water along the highways' green shelterbelt, making them more frequently observed near these roads. Notably, he said that the birds have adapted by learning to cross the roads. "This adaptation has led them to live closer to the desert highways," Xu said."So they face a higher risk of becoming roadkill."

To mitigate the risk, Xu suggested implementing speed limits on road sections frequented by the ground jays, aiming to enhance their protection while balancing the needs of human transportation.

Wang Kexin, a master's student from Sun Yat-sen University in Shenzhen, Guangdong province, discussed the impact of road heat traps on the risk of snake roadkill in Guangdong. She explained how roads, as ideal sunbathing spots for snakes that regulate their body temperature externally, increase the risk of roadkill incidents.

She said that due to the region's warmer climate, amphibians and reptiles are particularly vulnerable to roadkill in Guangdong. During her research, she, along with her professor Ma Liang and classmates, documented 29 different species of snakes that had fallen victim to roadkill.

Zhao Ying, a research and conservation officer from the Chinese Felid Conservation Alliance, a nonprofit organization specializing in the protection of wildcats, spoke about how challenges arising from roads running through leopard habitats in northern China can be addressed.

She detailed the collaborative efforts of her team in designing and constructing ecological corridors along a new highway that traverses leopard habitats in the Taihang Mountains. These corridors aim to facilitate safer crossings for the endangered North China leopards, helping to mitigate the impact of road expansion on their natural habitat.

Qin Haixu, director and senior engineer at the Nanjing Institute of Environmental Protection Science, opened the afternoon roundtable with a report on the construction of ecological corridors for terrestrial vertebrates in developed areas. He discussed solutions for roadkill incidents faced by wildlife in Laoshan National Forest Park in Nanjing through the establishment of eco-friendly corridors.

A snake is observed on a road in Guangdong province on June 6. (CHEN GENRUN/FOR CHINA DAILY)

Citizen scientists

Since the launch of the China Roadkill Monitoring Network in 2023, it has received substantial support from citizen scientists who diligently record roadkill incidents, preserving the memory of each creature's existence and providing crucial data for the project.

The forum invited five outstanding citizen scientist representatives, presenting them with certificates to acknowledge and encourage their exceptional contributions.

One of the representatives, Gao Ziming, a graduate student from Huazhong Agricultural University's College of Fisheries in Wuhan, Hubei province, shared his experiences documenting roadkill.

Gao, an enthusiastic nature lover, has become one of top contributors to a roadkill survey mini-program by uploading 318 roadkill records this year. His dedication to documenting these incidents has provided him with unique opportunities to observe various species of wildlife. Gao said that this activity has allowed him to discover a few insect species that he found exclusively on the carcasses of certain animals.

Pang Hanrong, a science teacher at a primary school in Zixing county, Hunan province, spoke of how he conducted a roadkill survey around the Dongjiang Lake scenic area from April to November last year. During this period, Pang, sometimes accompanied by a few of his students, regularly visited the area in the early mornings and late afternoons to document roadkill incidents. Over the course of seven months, he recorded 400 roadkill incidents involving 35 different wildlife species.

"The initial curiosity my students had about wildlife quickly turned into heartbreak as they witnessed these roadkill incidents," Pang said."This experience motivated them to actively promote conservation efforts on campus. The survey transformed them into keen observers of nature and active practitioners of ecological conservation."

For professor Li, the students' growing awareness of roadkill signifies the positive impact of his project. "I hope that through our efforts, more people become conscious of roadkill and its negative impact on wildlife, and that more drivers will be willing to slow down for animals crossing the roads," he said. "Even a small shift in people's attitudes could lead to the survival of millions of animals."