The ecological "earthquake" caused by rabbits, this "war between humans and rabbits" lasted for a hundred years!

Nowadays, the concept of ecosystem is familiar to almost everyone. However, as a scientific concept that is less than a hundred years old, people still have a lot of misunderstandings about ecosystem: for example, no matter it is as small as a pond or as large as an ocean, any ecosystem has amazing complexity, and any rude changes to the ecosystem may eventually lead to uncontrollable consequences, and even backfire on humans themselves.

Human-Rabbit Wars: The Backlash of Interfering with the Ecosystem

At the end of the 18th century, Europeans discovered that Australia had vast grasslands and was free of the threats of birds of prey and weasels that they had to guard against when raising rabbits in their hometowns in Europe, so a group of colonists happily transported dozens of rabbits from Europe to raise on their farms. However, they did not expect that there were no predators in the ecosystem of the Australian continent that could control the proliferation of wild rabbits, and that it was difficult to withstand the catastrophic consequences of the wild rabbit population.

A few years later, the dozens of rabbits on the Australian farms turned into hundreds of thousands, and escaped to the grasslands hundreds of kilometers away from the farms. After a few decades, the number of wild rabbits exploded from hundreds of thousands to more than 10 billion. The excessive number of rabbits swept across the land of the Australian continent, causing a sharp decline in soil and water conservation capacity in most areas and grassland desertification. The rapid deterioration of the ecological environment has led to the extinction or endangered extinction of dozens of rare species such as kangaroos, wallabies, and bandicoots, and has also caused huge losses in agriculture and animal husbandry - in pastures and farms full of rabbit holes, agricultural and animal husbandry machinery cannot operate, and 1 billion sheep have been deprived of pasture. People are wondering who started this disaster while trying to reverse it all.

The rabbit's natural enemy, the red fox

Initially, people tried to eliminate rabbits with traditional hunting and netting. They spent a huge reward and effort, but all failed. After that, people decided to try biological control - introducing the red fox, the natural enemy of rabbits, from Europe, but soon discovered that in addition to rabbits, red foxes would also hunt a large number of rare marsupials that were ubiquitous and slow-moving, so people had to go back and eliminate red foxes. Later, people built three of the most ambitious fences in human history, hoping to keep out rabbits. But because of the damage caused by floods and strong winds and the rabbits' ability to dig holes, the more than 3,000 kilometers of fences quickly lost their effectiveness, stretching across the Australian grasslands like a joke.

In addition, the government also tried to send out the air force to spread poison, but the rabbits quickly adapted to the poison, and the grassland ecosystem suffered a heavy blow. With the development and progress of science and technology, people tried to use modern molecular biology technology-rabbit myxoma virus to eliminate rabbits. Although the myxoma virus could once control up to 95% of the rabbit population, the rabbit's immune system eventually adapted to the virus and the number recovered to hundreds of millions. People finally realized that rabbits will always exist on the Australian continent and can only be controlled, not killed.

Why are rabbits so powerful in Australia? The reason is actually very simple. There were no rabbits in Australia. All rabbits are invasive species introduced by humans. They are the backlash caused by human's rough intervention in the ecosystem.

The introduction and extermination are not worth the cost

The story that happened in Australia has actually been repeated in other countries. The British introduced gray squirrels from America for "good looks", but the herpes virus carried by gray squirrels spread in Europe, and the chain reaction led to the extinction of endangered species in the native land, threatening the natural replacement of forests and shrubs, which in turn affected agriculture and animal husbandry; Americans tried to introduce Asian carp to eat the algae that were rampant in rivers and ponds, but they did not expect that carp had few natural enemies in the river and lake ecosystems of the United States, and they proliferated on a large scale, causing billions of dollars in losses to the ecological environment and the fishery market; China also introduced species such as red-eared sliders, African giant snails, and Canada goldenrod for various reasons, causing huge losses to the ecology and property.

These are just some of the relatively simple examples of invasive species introduced by humans. In fact, whether it is the widespread presence of the pesticide DDT, plastic microparticles and heavy metals in the world's oceans, or the spread of viruses caused by the indiscriminate consumption of wild animals, there are countless examples of the losses suffered by humans due to their disrespect for nature.

Respecting the ecosystem can lead to harmonious coexistence

In fact, there are also hopeful cases of respecting ecosystems. For example, in the giant panda protection work that spans thousands of miles, people did not capture wild giant pandas and raise them in cages, but instead preserved China's most important southwestern mountain forests as the giant pandas' natural habitat.

On the one hand, while protecting giant pandas, we also protect the forests, water and soil of this area and thousands of other wild animals; on the other hand, large-scale returning farmland to forest, natural forest protection projects and key restoration of small-area forests can protect millions of residents downstream of rivers from floods and mudslides, and provide them with clean water and safe lives. Although our understanding of the ecosystem is still at the stage of observation and exploration, for the long-term balance of the ecosystem and for the sustainable development of human society, every change we make to the ecosystem must be full of respect for the ecosystem.

Source: Knowledge is power

Written by Wang Fang (PhD in Zoology from Peking University, Researcher at the School of Life Sciences, Fudan University)