A new study from UK researchers has confirmed what Australian farmers have long feared: the continent's devastating mouse plagues are becoming more frequent and intense due to climate change. The report, published in the journal Nature Climate Change, links rising temperatures and altered rainfall patterns to population explosions of the house mouse (Mus musculus) that have ravaged crops from New South Wales to Queensland.
Lead author Dr. Emily Carter of the University of Cambridge described the findings as a 'canary in the coal mine' for global agriculture. "The mechanisms are clear: warmer winters reduce mouse mortality, while wetter springs boost food availability. Combined, they create perfect conditions for exponential population growth." The study analysed 50 years of data, revealing a 300% increase in severe outbreaks since 1990.
Australia's most recent plague, in 2021, caused an estimated AUD 1 billion in losses. Farmers described mice eating through grain stores, gnawing wiring in tractors, and even biting livestock. The new model predicts that under a 2-degree warming scenario, such outbreaks could occur every three years, up from the current one-in-ten frequency.
The agricultural sector is already struggling with drought and bushfires; this adds a biological stressor that compounds existing pressures. "We're seeing a systemic breakdown," said Dr. Carter. "Mice are a symptom of a biome out of balance." The study calls for integrated pest management, including conservation of native predators and early warning systems based on climate forecasts.
There are no easy solutions. Rodenticides are ecotoxic and non-selective, killing beneficial animals. Biocontrol using viruses faces regulatory hurdles due to safety concerns. "The most effective long-term strategy is to stabilise the climate," said Dr. Carter. "But in the interim, farmers need support to adapt."
Australia's government has allocated AUD 50 million for research into fertility control and new control methods. However, critics argue this is insufficient given the scale of the threat. "We're in an arms race with evolution," said Dr. Helen Vance, Science and Climate Correspondent. "Every warm winter gives the mice another evolutionary step."
The broader implications are stark. Mice plagues exacerbate food insecurity and drive up global grain prices. Australia is the world's fourth-largest wheat exporter; repeated outbreaks could destabilise supply chains. "We are watching a slow-motion collapse of agricultural stability," said Dr. Vance. "The mice are a harbinger."
For now, farmers are left to count the cost. As one put it: "We're fighting a war on two fronts: the weather and the mice. And both are winning."
