Australia’s Historic Nemesis: The Bunny Rabbit
European Rabbits in Australia. Source: (Wikipedia)
Australia is home to 66 venomous species of animals. Some, like the funnel web spider, the Dubois sea snake, the taipan snake, the blue-ringed octopus, and the box jellyfish are the stars of internet clickbait lists titled “World’s Most Deadliest Animals.” Aside from poisonous species, Australia is home to the saltwater crocodile, whose aggressive tendencies mixed with human habitat encroachment invariably result in at least a couple of deaths per year. By reputation and reality, Australia is the home to some dangerous animals.
But curiously, few people realize that perhaps the most dangerous species to Australia are none of the notorious species above, but rather Oryctolagus cuniculus, the European rabbit. The history of the rabbit in Australia is a cautionary tale concerning the dangers of human meddling with ecosystems.
The first rabbits came to Australia in 1788 with the First Fleet, which brought the first British colonists to the continent. These colonists were mainly prisoners who were sentenced to “transportation” and were guilty of minor crimes such as petty theft. Their rabbits did not seem to be numerous by most accounts. Meanwhile, on Tasmania, a feral population had exploded so that by the 1820s it was overrunning the island.
The warning signs were duly ignored. Many of the new colonists believed that the introduction of foreign flora and fauna to Australia would enrich what they believed to be a barren Australian landscape. Some of these formed “Acclimatisation societies.” Over time, colonists would introduce animals on purpose or by accident, to a land not remotely prepared for them. The impact of this was and is devastating.
One member of the Victoria Acclimatisation Society was Thomas Austin (1815-1871), who held a nearly 30,000-acre estate in Barwon Park, Victoria. Austin had been an avid sport hunter in England and nostalgic had 24 wild rabbits shipped to him. He released these in 1859 with the idea of hunting them for sport. He had also released hares, blackbirds, and partridges. He was praised for the action, albeit briefly.
Without natural predators, the rabbits multiplied, like rabbits. By 1865, Austin reported that he killed 20,000 rabbits on his estate but thought there were at least 10,000 left. In 1867, Queen Victoria’s son, Prince Alfred visited the Austin estate. They held a shooting party and killed 1,000 rabbits in three and a half hours. On a second visit, they shot 1,532 of the creatures.
Soon, the rabbits could not be contained and started to spread across the country.
The impact of the rabbits upon the Australian ecology cannot be understated. They go for succulent plants eating all including the roots. They killed trees by gnawing a ring around in the bark. This caused erosion and the degradation of pastureland as well as putting immense pressure on native species.
The Australian authorities soon realized the problem and began to go after the rabbit. In 1883 the legislature passed the “Rabbit Nuisance Act” which allowed the government to “enter upon all lands to enforce rabbit destruction.” It was reported in an 1887 issue of Scientific American that 2,285 men were employed as rabbit hunter-killers and had managed to kill 852,739 individuals. The Australian government paid well. An official giving an update on the anti-rabbit initiative stated “…it is now reported that a number of skilled tradesmen have been known to abandon their ordinary pursuits and to take to rabbiting as a more lucrative occupation.
By 1890 the government had paid well over $7 million (Australian dollars) in bounties for rabbit scalps. By 1911, Australia was selling its rabbits to Europe for cooking. Trapping, poisoning, fumigation, and destruction of warrens were all methods employed. Australians built 2,000 miles of fencing to keep rabbits out of the uninfested sections of the country – this did not work. They tried different invasive species: Foxes and dogs were allowed to run wild in an attempt to devour the rabbits, but it was found that they went instead for ground-nesting birds and newborn lambs.
The problem was overwhelming. By 1928 rabbits were in two-thirds of the country. By 1950 estimates of the rabbit population ranged to up to 1 billion. The rabbit was not a threat but had become a plague of a continent.
Scientists thought they found a solution to the problem: biological warfare. In 1950, they introduced myxomatosis which is a viral disease that almost always kills European rabbits. This worked incredibly well and almost eliminated the invasive species entirely. Within two years, the estimated rabbit population fell from 600 to 100 million.
However, in the ensuing decades, natural selection bred strains of rabbit that were resistant to the myxomatosis virus. By 1991, rabbit numbers had increased again to 200 million. Researchers then gave it another go and found that the Rabbit Haemorrhagic Disease virus (RHD) might be more efficient. While testing on an island off South Australia in October 1995, the virus escaped to the continent. This had some impact but then it was found that a benign form of the virus was immunizing rabbits and did not work effectively in all environments.
In 2012, scientist identified a Korean strain of RHD, both highly lethal and highly contagious being spread by multiple vectors. It was also found not to infect native species. After extensive testing, it was released in March 2017 at 600 sites. Owners of pet rabbits were advised to have their pets vaccinated. There are also fears in other areas of the world of the virus spreading to regions where rabbit populations are vulnerable.
Data is scanty as to results of this latest effort to control the problem, but it appears likely that Australia will never fully eliminate this invasive species as well as others that had been introduced over the last two hundred years.
Tags: australia | bunny rabbit
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