A virus is taming Australia’s bunny menace, and giving endangered species new life

[NickB79]

2. Viral measures were tried in the 1950's, but resistance quickly built up

https://en.wikipedia.org/wiki/Rabbits_in_Australia#Biological_measures

In 1950, after research was conducted by Frank Fenner, myxoma virus was deliberately released into the rabbit population, causing it to drop from an estimated 600 million[19] to around 100 million. Genetic resistance in the remaining rabbits allowed the population to recover to 200-300 million by 1991.

To combat this trend, Commonwealth Scientific and Industrial Research Organisation (CSIRO) comprehensively tested, over three years from June 1991, the release of calicivirus to cause rabbit haemorrhagic disease (RHD).[20] The virus escaped from a quarantine compound on Wardang Island, South Australia, where field tests were being carried out on the potential of the virus for biological control of wild rabbits, and by late October 1995 it was recorded in rabbits at Yunta and Gum Creek, in northeastern South Australia.[21] By the winter of 1996, the virus was established in Victoria, New South Wales, the Northern Territory and Western Australia. The success of the virus was found to be higher in extreme heat, because it appears there is another calicivirus in the colder, wetter areas of Australia, and that this virus was immunising rabbits against the more virulent form.