Doing things that have never been done before in the country, drilling into the grass with a flashlight and paper, welcoming a stranger grid in 56 communities in Shanghai on rainy nights | communities | strangers

As the sky darkened, five suspicious looking strangers caught the attention of security guard Ling Congyou in the new Shanghai Garden villa community.

After riding the electric scooter and following for a while, he noticed that these people were scattered. Except for a mother and daughter, everyone else was walking alone, drilling into the roadside green belt with a flashlight, and holding a board with a few pieces of paper on it in his other hand. Unable to resist curiosity, Ling Congyou approached to inquire, and the other person's answer left him even more puzzled: "A census of raccoon mouths.".

It wasn't until someone presented a photo of the raccoon that Ling Congyou suddenly realized: "It's it. I met it twice in the early morning of the previous two months, and when I saw it, I ran away."

Last night, a similar scene occurred in 56 communities in Songjiang, Minhang, and Qingpu districts of Shanghai. More than 100 volunteers braved the rain in the communities to explore the traces of raccoons under the same roof, which also means that the second "raccoon population census" in Shanghai has been fully launched.

find

With the rapid development of cities, the boundaries between urban and suburban areas have gradually blurred, causing many natural habitats for wildlife to no longer exist. As a result, a phenomenon known as "wildlife entering cities" has become increasingly frequent in recent years.

The national second level protected animal raccoon, which now lives in the same community as some residents, is a typical case. In history, there has been a rich composition of mammal species distributed in Shanghai, including several national first and second level protected wild animals such as the little spirit cat, raccoon dog, roe deer, leopard cat, as well as other species such as the yellow weasel, dog badger, Northeast hedgehog, South China rabbit, and red bellied squirrel.

Many species are unable to keep up with the rapid development of cities, but raccoon dogs are an exception. They have gradually adapted to the urban environment, their numbers continue to increase, and their distribution areas continue to expand. They are a typical "wild animal entering the city".

MengMeng's little raccoon dog, the breeding period from may to August every year, especially the breast-feeding female raccoon dog, is to protect the young during this period, and the territorial behavior is stronger. after being provoked or dangerous, the stress response is much stronger than usual.

A nest of raccoon dogs and a litter of young raccoon dogs were found under a corner less than 10 meters from the main road in a residential area in Shanghai. Photo by Zheng Yunxiang

After the explosive growth in numbers, conflicts and contradictions between wild animals and humans are inevitable. Having sufficient knowledge is the foundation for how to be proactive, scientifically and reasonably deal with the issue of "wildlife entering the city". In the past, little was known about how many raccoons and even what they looked like in Shanghai.

In 2019, the Shanghai Forestry Station, the Conservation Biology Research Group of Fudan University, and the Shanshui Nature Conservation Center jointly launched the "Raccoon as Home" project, and launched the "Raccoon Population Census" in 2022. This is the first urban wild mammal survey activity in China to be conducted in a citizen scientific organization in a mega city.

The "raccoons think home" and "raccoon population census" have made many valuable discoveries and conclusions.

Firstly, the raccoon density in the communities with raccoon distribution was calculated: out of the 50 surveyed communities, 22 had raccoon distribution, with an average of 10.82 raccoons per community and an average density of 1.08 per hectare.

If 1.08 birds/hectare are are taken as the reference value and the density of raccoons in the residential area does not exceed it, the raccoons are basically in a "latent" state, and the residents have less chance of meeting them. even many residents do not know that there are raccoons in the residential area, even if they are "under the same roof", they can be basically at peace.

But if the density of raccoons in the community far exceeds it, it will greatly increase the probability of people and raccoons meeting or even causing conflicts. Among the 22 communities with raccoons distributed, there are 7 communities with no less than 10 raccoons, 6 communities with a raccoon density of over 1 per hectare, and the highest community has over 50 raccoons, with a density of 5.8 per hectare.

Wang Fang, a researcher at the School of Life Sciences at Fudan University, said that the total number of raccoon dogs calculated at an average density of 1.08 per hectare is closer to the estimated number of wild raccoon dogs in Shanghai by the research team in previous years, ranging from about 3000 to 5000.

By comparing similar communities horizontally, the research team also discovered effective methods for controlling raccoons: managing cat food feeding and wet garbage.

"The vegetation index, population density, and other parameters are similar, but the number of raccoons in the same type of community is nearly twice as high." Feng Yidi, a scientific consultant at the Shanshui Nature Conservation Center, said that analyzing communities with higher raccoon density, the reason for having one more raccoon per hectare is is because some people do not listen to advice and feed them indiscriminately, and wet garbage disposal sites are left unattended for a long time.

So, controlling food and drink is an effective way to control the proliferation of wild animals. In addition, during the non breeding period of raccoons, filling the settlement gap at the bottom of the building after all raccoons in the cave have left can effectively reduce the number of raccoons in the community.

The raccoon dog rummaging through the garbage in the night.

In Shanghai, wild raccoons seem to have a tendency to spread along the river.

This study also provides important references for wildlife conservation departments to implement policies.

"How many raccoon dogs are suitable per hectare? This is actually a question of ecological carrying capacity and the tolerance of surrounding residents, but we were not clear about the specific answer in the past." Li Zirong, Deputy Director of Shanghai Forestry Station, said that now with the value of "1.08 raccoon dogs per hectare", it is a good start and will be further refined in the future. It can become one of the reference standards for whether to take measures such as sheltering and releasing wild animals in cities. After evaluation, if the density of raccoons approaches the standard value, relevant departments need to be proactive and intervene.

Touching

According to the questionnaire surveys organized in 2021 and 2022, combined with visiting surveys, volunteer feedback, and complaint information provided by the forestry department on the 12345 platform, as of November last year, there were at least 260 communities or green spaces in Shanghai with raccoons distributed. Except for Chongming, raccoons were recorded in all other districts of Shanghai.

According to the Shanghai Forestry Department, the number is likely to approach 300.

The first "raccoon population census" only covered 50 residential areas and has not yet obtained a complete picture of the distribution of raccoons in the city. In addition, have there been significant changes in the population and distribution of raccoon dogs over the past few years? Why has it changed? These mysteries require continuous promotion of the "raccoon population census" to unravel.

"Citizen science is likely to be the only sustainable and effective method for wild raccoon surveys in Shanghai at present. The survey, which used to take several months for a small team to complete, can be completed in just two weekend evenings with the efforts of hundreds of people." Wang Fang said that when the large-scale offline "raccoon population census" was launched for the first time in 2022, the strong environmental awareness, high scientific literacy, and responsible and efficient participation of citizens in the survey deeply impressed him, and strengthened his confidence in continuing the project.

This year's "raccoon population census" will expand the scope of investigation from Songjiang to Songjiang, Qingpu, and Minhang. Feng Yidi explained that this is because the two newly added areas have shown a trend of concentrated distribution and increasing numbers of raccoons.

After determining the three areas to be investigated, the investigation team first covered these areas with a uniform grid table, and removed the grid with the land area less than 50% of the grid area in the grid at the edge of the table to obtain 177 grids.

Then, based on parameters such as vegetation index and population density, 177 grids were divided into 4 types. The grids to be surveyed were randomly selected from these 4 different types of grids in a uniform proportion. Finally, 2 communities were selected from each grid and volunteers were assigned to participate in the survey.

In the end, 56 communities were selected, and more than 100 volunteers were divided into 56 groups with over 100 routes. They visited residents and property on two Saturday nights and searched for the whereabouts of raccoons on designated walking routes. They also had to use specialized mobile software to record the time, location, quantity of raccoons they saw, as well as what they were doing, their reactions to people, whether they had skin diseases, and whether anyone was feeding cat food or littering wet garbage indiscriminately.

Late Night Encounter Raccoon King Fang

The raccoon soup photographed by volunteers during the investigation of the community is easy to welcome.

The raccoon dog photographed by volunteers while investigating the community was wearing a GPS collar and photographed by Sun Gonghao.

"I envy the ecological environment and atmosphere of Shanghai a bit, because of the same interests, so many people from all over the world come together." Yang Yunyuan, a doctoral student in sociology at Peking University, served as the leader of the investigation team for the new Shanghai Garden villa community. She told reporters that she has specialized in researching the topic of "moving elephants" in Yunnan and has always been interested in wildlife. However, she has never seen raccoons in her hometown of Yunnan and Beijing. This time, she came specifically from Beijing and plans to stay in Shanghai for half a month to search for raccoons and study the harmonious coexistence between humans and raccoons. The other members of the group also do not live in Songjiang. A friend rushed over 20 kilometers from Huangpu District without any complaints.

Dai Aiyu, who works in the advertising and creative industry, is also curious about raccoons: "I only saw it online before and thought it was cute." Dai Aiyu said she loves small animals and often participates in public welfare activities to rescue stray animals. The "raccoon census" is a citizen science activity she has participated in for the first time. "It's very different from rescuing cats, dogs, and dogs. Human intervention in raccoon life is the scientific way to treat them, which really touches me."

Yang Shanshan and her 5-year-old daughter Song Siyu walked in the neighborhood in the rain for over an hour without finding any raccoons, but she said to her daughter, "It's normal not to see raccoons. This is science, and it's impossible to succeed easily."

It is reported that this Saturday's "raccoon population census" only recorded raccoons in 22 communities or residents who were interviewed clearly saw raccoons, with a high failure rate. However, this setback has brought a lot of knowledge. For example, raccoons are more likely to appear in communities with lower residential density; The environment is good, with shrubs, soil slopes, vegetable fields and melon sheds that raccoons like, as well as water sources and feeding places such as landscape water bodies and fountain pools; There are many voids under the wall foundation, and raccoons only need to dig up the floating soil on the surface of the green belt on the wall foundation to find a deep and safe "underground palace".

"At least knowing where to shine a flashlight makes it easier to see them, and also knowing that the probability of encountering them late at night is higher, having such small gains is very satisfying." Yang Shanshan said that she will continue to work hard next week to contribute to the urban ecological environment.

Volunteer group photo