Can we find a way to coexist harmoniously with wildlife in cities?
By Yuan Yanan
On the evening of July 7, Shanghai resident Chen Yuanyuan was out on an after-dinner walk on a cobble-stone path in her residential area, wearing pants and slippers, when a racoon dog (Nyctereutes procyonoides) the size of a cat darted through the high grass. The animal scratched the back of her heel before leaning its tiny head on her ankle. “I felt it clinging to my ankle when it suddenly jumped back into the high grass on the other side of the path,” said Chen.
The incident resulted in a large gash on Chen’s foot. In the hospital emergency room, she was vaccinated for rabies. Since then, the formerly fearless woman has refrained from going out at night. When she takes a walk in her neighborhood, she dresses more carefully and wears proper shoes.
News of Chen’s encounter with a racoon dog jolted the nerves of the whole neighborhood. The neighborhood committee received more complaints about the racoon dogs as well as requests to have them moved or caged.
The incident drew the attention of Wang Fang, a researcher at the School of Life Sciences of Fudan University, who specializes in wildlife population, community ecology, and conservation biology. In recent years, he led a team of volunteers to survey the racoon dog population in Shanghai.
The racoon dog is a canid indigenous to Shanghai which has been fortunate enough to enjoy a population increase in recent years, with its habitat expanding from the city’s west end to the east. Wang Fang sees this as a sign of the city’s ecological restoration. The racoon dog is born timid and doesn’t dare get close to humans, especially before a year of age. Therefore, under normal circumstances, they are unlikely to attack people. After on-site surveys, Wang determined that the woman had encroached on its territory, which indicates an imbalance in the relationship.
“Feeding wild animals is against the laws of nature,” said Wang. “When people feed wild pups, they stop being afraid and keeping a distance.” His survey team witnessed a fierce melee in a residential area over cat food involving dozens of adult racoon dogs as their young ones looked on eagerly.
“New-born racoon dogs should look for new habitats and learn new skills. But human feeding has changed their survival habits and dramatically increased their population. When they fail to get enough from man, they will vent their anger against us,” Wang added.
Such incidents have awoken many to the breadth of the wildlife sharing urban spaces with people. We should figure out how to coexist harmoniously with wildlife in cities.
The rapid process of urbanization has brought about dramatic changes in wildlife habitats. In this process, some wild animals were forced to migrate to habitats more suitable for survival, while others that could not adapt to a new environment vanished forever. In contrast, some viable species have begun to shift habitats to exploit the plentiful resources cities have to offer.
Wang Fang believes that some wild animals have adapted to urban life far faster than we can imagine. For example, the North American raccoon (Procyon lotor) has learned to identify traffic and different types of urban buildings over the last 20 to 30 years. Yellow weasels are generally known as nocturnal animals, but without human interference, they hunt during the day fairly frequently. In urban areas, their day-time activity drops significantly compared to the night. Under natural conditions, if a person approaches nests or habitats of badgers or racoon dogs, they growl ferociously and attack quickly. In urban environments, however, they tend to be more tolerant.
From a biological evolution perspective, urbanization is having a profound impact on species. In 2008, a French scientist hypothesized that urbanization has already affected the evolution of species. He noticed that Tibetan hawksbeard roots (a herbal plant) grown in the city produce larger seeds than the same species grown in the countryside. He thought that the heavier seeds would be less likely to be blown by the wind onto far-off concrete roads, with a tendency to drop in nearby soil which would lead to a higher survival rate.
Dutch urban ecologist Menno Schilthuizen also looked at the impact of large-scale urbanization on wildlife evolution. He calls cities “pressure cookers” on biological evolution. He argues evolution which used to take hundreds of years or more has been dramatically accelerated in cities.
In his book Darwin Comes to Town, Schilthuizen quoted some examples of species that have thrived and evolved in cities. For example, the mice living in different districts of New York City exhibit different DNA profiles. The urban heat-island effect causes the temperature in cities to measure higher than in surrounding areas. Snails living in urban areas become lighter in color to absorb less heat. Pigeons living in cities look darker because the melanin in their feathers insulates them from toxic metals. Scavenger crows in Sendai, Japan, learned to crack nuts with passing vehicles. Lizards in Puerto Rico have evolved claws more suitable for latching onto concrete. Moths in Europe have become less attracted to deadly artificial light. He cited these as evidence that urban environments are accelerating evolution of species in amazing ways.
Living with Animals
While wild animals seek to integrate into cities, humans are beginning to recognize the importance of environmental protection and inclusiveness of urban biodiversity. With the improvement of urban environments, more wild animals are returning to human life.
In the 1970s, water pollution in Singapore caused the otters in its rivers to disappear. In 1977, the Singaporean government launched the Clean River Campaign to improve water quality. In 1998, the aquatic mammal showed up again after a long absence. Today, about 90 otters share the urban space in Singapore. Despite a 2017 incident in which an otter bit someone, the locals have overwhelmingly enjoyed their company. In 2016, the mammal was voted the national mascot for the country’s National Day celebration. The Singaporean government has also placed icons and signs in the hot spots of otter activity to protect them and manage potential conflict with man.
“The formation of cities is the result of humans being attracted by the soil and water of certain locations, which is also attractive to wildlife,” commented Wang Fang. “Human beings didn’t congregate at these locations before wild animals.” Humans demand material and spiritual nourishment from urban biodiversity but doing so requires managing emerging problems effectively. “For example, the improvement of urban environments can cause the squirrel population to grow and start stealing our cat and dog food or chewing up our stuff. Similar afflictions have persisted in countries with great ecosystems,” Wang said.
In Berlin, Germany, the rivers, lakes, and green spaces in the urban area have attracted more than 3,000 wild boars. The animals’ settlement in the urban area has been troublesome for the surrounding parks and communities. In Bristol, England, more than 20 red foxes can be found per square kilometer in the urban area, which poses a threat to many rare terrestrial mammals and small birds.
China has faced similar problems in recent years. In Shenzhen, leopard cats were spotted in the residential area of Overseas Chinese Town. Wild boars found their ways to the city centers of Nanjing and Hangzhou, posing new challenges for urban governance. Experience has shown that measures such as poisoning or selective slaughter do not control the development of such species. Such intervention, on the contrary, can lead to ecological chain disasters.
Conservation of biodiversity in cities is more complex than in the wild. Wang Fang believes that in cities, man needs to be more proactive in biodiversity design and scientific management. In urban landscape design, biological management needs careful consideration. “For example, we need to consider how green space should be built, how canals should be built, and how the basic biodiversity of a city should be maintained through practical measures,” said Wang. “For some harmful species, you have to intervene. For example, everyone supports controlling rat infestations. In the farmland where pests and locusts are raging, control measures are a no-brainer.”
Much remains to be done on this front. The public is being discouraged from feeding wild animals. The government is expected to organize volunteers and researchers to monitor and research wildlife to gather more detailed information.
Environmentally Sustainable Cities
According to 2018 UN statistics, more than half of the world’s population lives in cities, and the proportion is expected to rise to 66 percent by 2050. Cities have become an important part of natural ecology. However, urban biodiversity is facing many challenges: climate and local environmental changes, invasive alien species, and urban expansion into natural spaces which is resulting in habitat destruction and fragmentation that could threaten the survival of man and other species. A path to healthy urban-wild development is a must.
In the ASEAN region, coastal cities are economically vibrant, but excessive resource development and growing pollution are threatening the development of biodiversity. The ASEAN Biodiversity Outlook noted that if urban development is left unchecked and environmental considerations are not prioritized against economic and industrial progress, cities might eventually become unlivable. The report described how over-exploitation of biological resources and invasive alien species as well as other forms of biodiversity neglect pose a major threat to the healthy development of ASEAN cities. ASEAN has called on all member states to take active measures to enhance the public awareness on biodiversity conservation and integrate biodiversity into urban development planning. ASEAN also proposed building Environmentally Sustainable Cities and established the Environmentally Sustainable City Award to highlight role models for sustainable development of cities.
In October 2010, the Singapore Index on Cities’ Biodiversity (Singapore Index) was formally adopted by the international community. The index includes three categories of indicators: native biodiversity, ecosystem services provided by biodiversity, and governance and management of biodiversity. The Singapore Index has been instrumental in helping local, national, and regional government departments share information on measuring biodiversity. The index enables city managers to evaluate and monitor the progress of their biodiversity conservation efforts against their own individual baselines and adjust strategies accordingly.
China and ASEAN have accelerated cooperation on building eco-cities. In 2015, China-ASEAN Partnership for Eco-friendly Urban Development was established to boost cooperation in green and sustainable urban development. Today, more than 20 cities from across the region are involved in cooperation in urban planning, water management, and other areas.
Cities are the common habitats of man and wildlife. Much remains to be learned about how they can coexist harmoniously in an eco-friendly urban environment.