According to a new study in the Proceedings of the National Academy of Sciences, 24 British rabbits in 1859, as seemingly innocent Christmas gifts, would continue to be Australia's most destructive biological invasion.
Hares are not native to Australia and are considered invasive species. Farmers there say the animals quickly multiplied and destroyed their crops and land, which could lead to massive soil erosion and other environmental problems.
The researchers write that biological invasion is a major cause of environmental and economic damage. The colonization of Australia by the European rabbit is one of the most iconic and destructive biological invasions on record.
Using historical records, the researchers were able to piece together genetic evidence linking the invasion to Anglo rabbit imported in 1859 by a settler named Thomas Austin, and trace the population back to Austin's birthplace in England.
According to historical records, Austin started with only 24 rabbits on his sprawling Melbourne estate. But the researchers note that within three years, the animals have multiplied to thousands and continue to breed.
"Our findings suggest that, despite multiple introductions in Australia, it was this batch of British rabbits that triggered this devastating biological invasion, the effects of which are still felt today," said lead author Joel Alves, who is also a researcher at the Oxford University Research Institute.
"This incident sparked this great catastrophe in Australia; The fastest colonization rate of exotic mammals has been recorded. "Environmental changes may have made Australia vulnerable to invasion, but it was the genetic makeup of a small group of hares that triggered one of the most iconic biological invasions ever made.
While Austin wasn't the first to introduce rabbits to Australia — five of them arrived in Sydney in 1788 on the British First Fleet and imported at least 90 more rabbits over the next 70 years — the study says his descendants of 24 rabbits will rule the continent.
It concluded that almost all of Australia's 200 million hares could be traced back to the important shipment he received in 1859.
The researchers also looked at how rabbit populations survive and reproduce in Australia's harsh wilderness. Genetic analysis showed that unlike earlier Australian rabbits, which exhibited domestication traits such as "docile, fluffy ears and fancy fur," Austin's descendants of rabbits had a large amount of wild ancestry.
Co-author Mike Letnic of the University of New South Wales said: "If animals are raised for domestication, one of the things they lack is anti-predator behaviour, which is both learned and evolved. ”
Rabbit plague has occurred several times in parts of Australia for decades. Today, the continent is still battling hare populations.
The researchers said the report showed the importance of maintaining strict biosecurity in Australia.
"These findings are important because biological invasions are a major threat to global biodiversity, and if you want to stop them, you need to understand what makes them successful," the researchers said, adding that the incident reminds people that the actions of one person or several people can have devastating effects on the environment.