Since 1770, with the continuous development of the global navigation industry, more than 3,000 exotic species have landed in Australia, including birds, mammals, plants, insects and a large number of invertebrates. Among these exotic species, the Australian government is most troubled by the flood of hares and wild cats.
Australia has a unique climatic conditions and geographical location, evolved a lot of unique magical species in the world, such as kangaroos, platypus, emus, koalas, etc., these ancient species have also won Australia the title of "World Living Fossil Museum".
Endemic species of Australia: the rabbit-eared possum
As species from Eurasia and the Americas continue to be introduced to Australia, Australia's native ecosystems are quietly changing. The Australian government has spent $1 billion to control invasive species, including bounty hunting programs, booby traps, the introduction of predators and more, but it has been with little success.
Alien species are able to flood mainly because of the lack of native predators that can contain invasive species – which has a lot to do with Australia's unique ecosystem.
Topographic map of Australia
The Australian continent is the lowest and most primitive continent on Earth. In its 3.8 billion-year history of geological evolution, Australia has long been isolated from other continents, and many native species retain the characteristics of ancient species.
Although much of Australia is covered by desert, habitat types range from high mountains and plains to tropical rainforests. It is estimated that there are as many as 250,000 species of fungi in Australia, and only about 5% of the fungal species have been recorded so far.
In addition, 45% of Australia's birds, 84% of mammals and 89% of warm water fish are endemic to the Australian mainland. Australia is also the only continent in the world without cats. It is precisely because there are no top predators such as felines that the artificial introduction of wildcats has "become popular" after landing in Australia.
Australian wildcat
As a result, the australian continent's ecosystems are more fragile than those of other continents, and each new species introduced has the potential to disrupt the original food chain or food web. Once alien species overbreed, the situation may get out of control, from hares and foxes to wild cats and wild dogs, one tragic case after another has become a species disaster that Australia cannot let go.
The flood of European hares is entirely "made" by the Australian residents themselves.
In 1859, 13 European hares were introduced to Australia for hunting and entertainment. Unexpectedly, the fleeing rabbits only took about 50 years to spread across the entire Australian continent.
Flooded hares
In the beginning, Australians were optimistic about the breeding of hares, believing that it would not cause too many problems. But before long, the breeding rate of hares greatly exceeded their psychological expectations, and the situation gradually spiraled out of control, with Australian farmers suffering the first losses.
Later, Australian farmers and local governments joined forces to build fences to prevent rabbits from destroying crops, and the government even built a wall across Western Australia, but these measures failed to stop the rabbits' crazy expansion.
European hares are very adaptable and reproductive, and adult female hares can breed all year round, and can produce 4 litters per year, with 2 to 5 cubs per litter. Australia's ubiquitous meadows and bushes provide plenty of food and habitat for hares, making them a hare breeding paradise.
During the craziest period, flocks of hares could be seen everywhere throughout Australia, and the population reached a staggering 10 billion at one point. By 1885, there was a fierce "human-rabbit war" throughout Australia. The Australian government ordered a reward for the number of hares killed, and for a time, the hares became the target of the Australians' hunting.
In just two years, Victoria's bounty hunters killed 1.8 million hares, and the aborigines of New South Wales killed 7 million in one fell swoop, but this did not fundamentally solve the ecological disaster caused by hares.
The whole people kill the hare
By 1950, the Australian government had shifted its rabbit eradication to biological control — the release of specific myxomaviruses to control rabbit populations. In 1995, scientists proposed to use rabbit hemorrhagic virus (RHDV) to kill hares. RHDV is an RNA virus that hares die in 48 hours once infected with the virus. In 1996, the virus was effective, reducing the number of hares in localized areas by more than 90%.
Like the myxomavirus, hares soon developed antibodies to RHDV, and the effect of virus elimination became less and less obvious. There are currently about 200 million hares across Australia, and researchers are stepping up research into more deadly strains of rhdv virus to prevent further spreads of hares.
Wildcats landed in Australia around 1804 and were first introduced to control rat infestations. These feral cats originally originated from domestic cats, and the two are the same species, but due to their long-term life and breeding in the wild, they are becoming more and more wild.
Map of the population of australian wildcats
Wildcats are haunted, agile, and good at hiding their tracks, and it's almost impossible to count the exact numbers. It is estimated that the current number of wildcats in Australia is around 2.1 to 6.3 million, and these wildcats kill millions of birds and reptiles every day, which is a huge disaster for Australian native species.
Australia's national commissioner said the extinction of at least 20 species of mammals was linked to the introduction of wildcats. Wildcats also threaten the survival of more than 100 native species, including spotted cuckoos and anteaters. Feral cats can also carry the source of infectious disease, spreading it to other animals, domestic animals and even humans.
Wildcats are found in all of Australia's habitats, including forests, wetlands, grasslands and arid areas. Don't look at the wildcat is not big, but the lethality is very high, can successfully kill about 8 to 10 pounds of lizards, and even killed more than 60 pounds of kangaroos.
In South Australia, local residents once killed a 6.5 kg large wild cat and found Australia's endangered and rare species in its stomach, the black-footed rock kangaroo. If left unchecked, more endangered species will inevitably perish under the predation of wildcats.
Black-footed rock kangaroo (a small kangaroo)
In April 2019, Australia has listed wildcats as the "number one public enemy" and plans to kill 2 million wildcats by 2020. In order to kill wildcats in an all-round way, the Australian government has invested no less than $200 million. In the 230-year-long "man-cat war", Australia did not achieve the expected victory at all, and it is almost impossible to complete the culling of wildcats within a year.
Statistics from 2016 show that about 29 per cent of Australian households have domestic cats, or around 2.7 million. These domestic cats may also wander into the wild for some reason, and from this point of view, Australia's "cat extermination order" is unlikely to achieve "mission must be achieved".
In short, the introduction of a species is often accompanied by great risks, and the problems after blind introduction are endless. The Australians' failure to defeat the hare, the defeat of the wild cat, and the heavy price paid by the Australian government are living cases. It is estimated that for a long time, hares and wild cats will still run rampant throughout the Australian continent - this "alien species prevention and control war" that is related to the survival of Australia's native species has just begun.