A plague of mice in eastern Australia has been described as ‘like a decaying body’ by local officials, prompting the deployment of British biological control experts. The infestation, concentrated in New South Wales and Queensland, has reached levels not seen in decades, with farmers reporting crop losses of up to 100 per cent. The odour from decomposing rodents, combined with the stench of urine and faeces, has created conditions akin to a mass grave, according to regional authorities.
The British team, comprising specialists in viral and bacterial biocontrols from the Centre for Ecology and Hydrology in Oxfordshire, arrived in Sydney on Tuesday. Their mission is to assess the feasibility of introducing a targeted pathogen to reduce the mouse population without harming native wildlife or livestock. The outbreak has already prompted the Australian government to approve the emergency use of bromadiolone, a potent anticoagulant rodenticide, but concerns about secondary poisoning of raptors and other predators have accelerated the search for alternative solutions.
The mice, primarily the house mouse (Mus musculus), have multiplied explosively following a wet spring and abundant grain supplies. In some areas, densities have reached 1,000 mice per hectare. The economic impact is estimated at A$1 billion, with grain silos, hay bales, and stored feed destroyed. Health officials have warned of leptospirosis and salmonella risks, as well as psychological trauma among rural communities.
British biocontrol experts are expected to propose a field trial of a genetically modified mouse-specific virus that induces infertility. Similar approaches have been used with varying success against rabbits in Australia and New Zealand. However, the technology remains controversial, with environmental groups warning of unintended ecological consequences. The British team will spend two weeks conducting environmental impact assessments before making recommendations to the Australian Department of Agriculture.
A spokesman for the New South Wales Farmers Association said the situation was ‘beyond dire’, with some farmers abandoning their properties. The federal government has declared the plague a national emergency, unlocking disaster relief funds. The British involvement underscores the severity of the crisis, as traditional control methods have proved insufficient. The outcome of the biocontrol assessment is expected to shape Australia’s long-term pest management strategy.
