It only took 24 rabbits from England to trigger the current problems on the Australian farm
Sometimes a single misstep can have a cascading effect that can last for decades. A continuing example of this can be seen in Australia where feral rabbits of European descent eating crops and pasture are depressing agricultural productivity while challenging native species by competing for scarce resources, according to a report by smithsonianmag. .com.
These species pose a threat to 300 types of animals and plants while the destruction they cause to agriculture amounts to 200 million dollars each year.
Interestingly, analysis of the genes of these rabbits revealed that their high number of 200 million can trace their ancestry to probably a single shipment of 24 of these animals.
Scientific research which has been published in the Proceedings of the National Academy of Sciences, lends credence to an earlier theory suggested by historians that the threat of rabbits in Australia emanated from a single domain.
It all started in 1859 when at Christmas, a wealthy English settler in Australia, Thomas Austin, received 24 wild and domestic rabbits from his brother in England.
Speaking about the episode, Francis Jiggins, one of the study’s authors, told Nature News: “This single event triggered this huge disaster, ecological and economic, in Australia.”
Jiggins is an evolutionary geneticist at the University of Cambridge in England.
What is remarkable is that it was not the first time that rabbits walked on this continent. These mammals had reached Australian shores with the first British colonizers who arrived in 1788. Following this in the following 70 years, these creatures had been introduced to the region 90 times.
Still, the Austin case was the turning point because it was after that that they practically flooded the area. The rabbit population grew across the country at over 60 miles per year and within 50 years they covered the continent. Six years after receiving his gift, in 1865, Austin shared with local newspapers that had killed 20,000 of these creatures on his property.
Scientists to confirm the origin of these animals carried out a genomic analysis of 187 European rabbits that had been trapped from 1865 to 2018 in Tasmania, Australia, Great Britain, New Zealand and France. It turned out that a large number of Australian rabbits on the mainland were genetically similar and their ancestry was a mixture of wild and domestic.
It was also found that there were many similarities between the Australian rabbits and the one from the South West of England – where Austin’s family had picked up these mammals from to send them to him. Looking closely at mitochondrial DNA – which comes from the mother’s offspring – it was also revealed that a large number of Australian rabbits descended from five females introduced from Europe.
The rabbits donated to Austin had a wild ancestry that gave them an advantage in surviving in Australia. Compared to domestic animals, they had a better ability to avoid predators and adapt to terrain, study co-author Joel Alves told Nature News. Alves is an evolutionary geneticist at the University of Oxford.
Another distinctive advantage that these rabbits enjoyed was that in the mid-19th century, people who turned the backcountry into pastures killed the predators of these rabbits, thus making their survival easier and more comfortable.
Australian ecologist from the University of Adelaide, David Peacock, believes that the entire responsibility for the rabbit invasion should not be placed on Austin. In a 2018 study, which he co-authored, he suggested that there were several rabbit introductions that led to the invasion by these creatures. He told Science that aside from the Austin rabbits, there were others also introduced at the same time.
Peacock believes the current study has value because it could aid in the eradication of these invasive species. He told Science, “The best [we understand] origin, spread and genetics, the better we can manage Australia’s most serious pests.