What are the impacts of exotic species such as serval cats and black swans on Beijing? Expert answers

Beijing News Express (reporter Zhang Lu) reporter learned from the Beijing Municipal Landscaping Bureau today that the rescued serval cat has been sent to the Beijing Wild Animal Park Rescue Station in Daxing District for professional treatment, and its vital signs are stable. Deng Wenhong, a professor at the School of Life Sciences of Beijing Normal University, said that the serval cat is an exotic species, and if a population is formed in Beijing, it will definitely affect other cats in Beijing.

serval. Courtesy of Beijing Municipal Landscaping Bureau

Deng Wenhong said that the origin of the serval cat is Africa, so it is also called the African serval cat, its typical habitat is grassland, once the serval cat breeds in Beijing, forming a certain scale of population, it will definitely have a relatively large impact on other cats in Beijing. "For example, during the second national terrestrial wildlife survey, ocelots were recorded in many places in Beijing, and if serval cats formed a population in Beijing, it was a threat to ocelots, because from a competitive point of view, they were more similar in terms of ecological niche, habitat and food."

Deng Wenhong said that at present, there are more than 400 animals and plants in China that belong to invasive species, of which More than 200 are in Yunnan, and there are 36 species of plants and more than 20 species of animals in Beijing. Alien species are particularly viable and competitive, which will have an impact on native species in Beijing. For example, there are Brazilian red-eared turtles in the waters of Beijing's Chaobai River and Juma River, which will affect the original grass turtles and turtles in Beijing. "For Beijing, the Brazilian red-eared turtle has formed a disaster, the number of reptiles in Beijing is not much, in the case of the invasion of the Brazilian red-eared turtle, it is difficult to find the grass turtle and turtle in Beijing."

A few days ago, a black swan appeared in Beijing, causing concern among the public. Deng Wenhong said that for Beijing, black swans are also exotic species. Black swans are native to Australia and New Zealand. He said that during the Guangxu years, Germany donated 5 black swans, and at this time, black swans appeared in Beijing for the first time. In 1956, black swans formed a breeding scale in The Splendid Land of Beijing. At present, the two most obvious alien species in Beijing are the Brazilian red-eared turtle and the black swan.

Black swans have been able to reproduce and survive in Beijing and form a population of a certain size, with a population of more than 100 black swans in the Yuanmingyuan. Birds of the genus Cygnus also include giant swans, cygnets and warty swans in Beijing. Black swans have few natural predators in Beijing, and if their populations continue to grow, they will have an impact on the giant swans, cygnets and warty swans that inhabit Beijing, and compete. Black swans are near-human birds, not timid, have a wide range of food, and have strong survivability. On the contrary, wild giant swans, cygnets and warty-nosed swans are all national key protected animals, and their adaptability to the human environment is not as good as that of black swans.

How to artificially regulate the number of black swans? Deng Wenhong said that there are many means to restrict its reproduction, such as setting up fences on the surface of the water where it lives, etc., to restrict its breeding activities.

Beijing News reporter Zhang Lu

Edited by Feng Yajun Proofreader Li Lijun