The case in Australia

While France and England experienced an explosion in their rabbit populations, it bears no resemblance to what Australia is still experiencing today. It nevertheless took the English settlers seventy years of introducing traditional small game to establish Peter in this recently discovered land. In 1859, the Englishman Thomas Austin, a great lover of hunting, decided to import several couples of rabbits into his new homeland. An eagerly-awaited hobby that was to turn into a nightmare. Proving their undeniable ability to adapt, the rabbits, which encountered very few predators in this land of welcome, multiplied endlessly, reaching a record number of 600 million! They took advantage of the lack of competition, the clearing of forests and the recent cultivation of vast areas of land. Hence, they ruined the numerous squatters who had just found an easy way to make money from breeding the recently imported ewes.

Hunting, traps, fencing, explosives, the introduction of the rabbit’s natural predators (foxes, cats, etc.), and spectacular barriers were all methods that were used to try to overcome the problem. In the 1950s, the authorities authorised the introduction of a deadly virus: myxomatosis, accidentally discovered in South America in 1898 by Guiseppe Sanarelli (a pupil of Louis Pasteur). The disease is spread by fleas, flies and mosquitoes and causes the development of tumours and oedema that eventually kill the animal in less than two weeks. The European rabbit, which was the only animal susceptible to this deadly virus, was in danger. In the beginning, myxomatosis affected 90% of the populations in Australia and New Zealand, as well as in Europe, where it was illegally introduced. But the authorities didn’t count on the natural weakening of the virus and the incredible ability of oryctolagus cuniculus to resist it. The supposedly vanquished rabbit may have been weakened by this battle, but it was still there.

The authorities are currently considering the introduction of a new immunocontraceptive to manage the spread of the rabbit through the genetic modification of the trypanosome in the vectors of myxomatosis. “It is paradoxical in Australia to see inhabitants who endeavoured for 70 years to establish this species in their country turning against it”, stresses Lucienne Strivay. “It makes us realise that although we started out with something seemingly very harmless, it has resulted in humanity being faced with some very serious questions. We’re speaking here of biological warfare, i.e. a “living poison” in the words of Louis Pasteur, which alone could put a stop to this rampant prolificity! And all this comes at a time when we’re starting to take stock of the disappearance of so many species!”