The rabbit plague in Australia began with just two dozen rabbits landed near Melbourne in 1859.
The Australian continent, due to its isolation from the rest of the planet’s land masses, has developed and preserved a different, special and surprising fauna and flora for millions of years. Today, much of this diversity is threatened, mainly by humans, but also by another of their traveling companions: the rabbit.
Rabbits have invaded most of the Australian mainland and have a disastrous impact on the country’s ecosystem, threatening around 300 species of plants and animals and causing hundreds of millions of damage to agriculture each year. ONE new study has uncovered the origin of this disaster: Australia’s invasive rabbit population likely descended from two dozen wild English rabbits that arrived near Melbourne on Christmas Day 1859.
According to historical records, the first wild rabbits (Oryctolagus cuniculus) from Australia probably arrived with the first settlers in Sydney in 1788. Ships bringing rabbits docked on the coast for decades, but it was not until the second half of the 19th century that the population spread significantly, at a rate of 100 kilometers per year across the country.
Records also suggest that the spread of rabbits was due to a shipment of animals destined for a Thomas Austin in Barwon Park, southwest of present-day Melbourne. His brother had captured the animals near the family home in Baltonsborough, southwest England.
Australian rabbits from Baltonsborough, UK
Evolutionary geneticist Joel Alves of the University of Oxford and his colleagues wanted to know whether the genetic data confirmed the records. For this, they analyzed the genetic material of 179 wild rabbits captured in Australia, New Zealand, France and the United Kingdom, in addition to eight domestic rabbits of different breeds.
They found that most mainland Australian rabbits were genetically similar, having mixed ancestry of wild and domestic rabbits. Australian rabbits also had rarer alleles in common with rabbits from southwest England than with those from other parts of the UK. So it seems that in the end, the rabbits that threaten the Australian ecosystem came from Baltonsborough. Looking at mitochondrial DNA, which is inherited through the maternal line, the researchers concluded that most Australian rabbits are descended from about five females brought from Europe.
Furthermore, the genetic diversity of the rabbits declined as animals further away were trapped in Barwon Park and increased alleles (one of two inherited versions of a gene) that are rare or absent in wild rabbits. According to the researchers, these patterns confirm that the majority of rabbits in Australia originate from Barwon Park. According to the researchers, using genetic analysis to understand how unwanted animal invasions begin can help predict future invasions.
The advantage of wild rabbits that domestic rabbits did not have
The wild ancestry of rabbits was an important factor in their spreading across the continent so quickly. Wild rabbits tend to run away from stressful situations and dig burrows, so they were better able than domestic rabbits to escape predators and survive in difficult terrain.
The fact that pastures increased at this time and predators were increasingly removed may also have contributed to its spread. The fact that people transported them to other parts of the country, where they could also feel at home, also contributed to the spread of the animals, since rabbits are animals that rarely migrate more than a kilometer alone.
REFERENCE
A single introduction of wild rabbits triggered the biological invasion of Australia