Sterilization could be the next weapon in the war against rabbits in Australia, the chief of South Australia's calicivirus program said today. Ron Sinclair, the SA calicivirus release coordinator said the CSIRO [Commonwealth Scientific and Industrial Research Organization] was already working on ways of spreading a protein to rabbits to make them sterile.

According to the article, there are reports that rabbits had already grown immune to the calicivirus [that causes rabbit hemorrhagic disease, i.e., rabbit hemorrhagic disease virus (RHDV), which the Australians call rabbit calicivirus and the disease rabbit calicivirus disease or RCD]. It was hoped the protein would be spread in the same way as RHDV -- via insects.

Sinclair said three years' research had already been done but it would take about another 10 years before it [sterilization protein] could be properly developed. He said even if a sterilization program was developed, the onus would be on farmers to do more, rather than rely solely on biological control to destroy rabbits which caused millions of dollars damage to farming areas. [Further, he said that controls such as RCD and myxomatosis would never get rid of the last rabbit, adding farmers needed to rip up warrens to maximize the impact of the disease. He was quoted as saying, "If you just think a biological control agent is going to get rid of your rabbit problem, you're fooling yourself."

The article said that recent reports had suggested rabbit numbers were at 20 per cent of pre-RCD levels in some parts of the Northern Territory where warrens had not been ripped up. But Sinclair said the warrens were crucial to rabbit breeding and protection from predators.

He also said the day would come when rabbits became immune to RCD but there was no suggestion it had already happened.