As eastern Australia grapples with a plague of mice that has swept through farming communities, UK scientists are racing to develop scalable interventions. The infestation, driven by exceptional rainfall and mild winters linked to climate change, has destroyed stored grain, equipment, and livelihoods. Dr. Helena Vance reports for The Guardian.
The scale is staggering. In New South Wales alone, farmers report crop losses exceeding 50% in some regions. Mice have chewed through wiring, contaminated feed, and even invaded homes, forcing families to sleep in shifts to clean up feces and urine. The economic toll is estimated at AUD 1 billion and rising.
Dr. Emma Thompson, a rodent ecologist at the University of Cambridge, describes the crisis as a 'natural population explosion'. 'A single female mouse can produce up to 500 young in a season under ideal conditions. This year, those conditions prevailed across vast tracts of country,' she explains. The driving factors are a wet La Niña cycle, which boosted vegetation, followed by a warm winter that allowed mice to breed year-round without seasonal die-offs.
Yet the immediate options are limited and alarming. Farmers have resorted to spreading zinc phosphide, a potent neurotoxin that kills mice within hours. But this chemical is non-selective, endangering native wildlife, livestock, and pets. Moreover, resistance to anticoagulant rodenticides is on the rise, forcing higher doses and more toxic alternatives.
Here, the UK's expertise in integrated pest management offers a potential path forward. The government-backed Agricultural and Horticulture Development Board (AHDB) has been trialing genetic control methods, including the use of CRISPR to create 'daughterless' mice that produce only male offspring, gradually collapsing populations. Dr. James Cooper, a geneticist at the Roslin Institute, cautions that such approaches remain years from field use but could become a key tool. 'The challenge is ensuring ecological safety and public acceptance. A genetically modified organism released into the wild would be irreversible,' he says.
More immediate is the development of fertility control baits. Unlike poisons, these contraceptives induce temporary sterility without killing the animal. The UK Centre for Ecology & Hydrology has successfully tested a bait containing the hormone antagonist EP1 in captive trials, reducing birth rates by 70%. Field trials are now planned in cooperation with Australian authorities.
But time is running out. The mouse plague has a cyclical nature, with outbreaks typically ending after two to three years through a combination of natural predators, disease, and starvation. However, climate models suggest that such events will become more frequent as Australia's rainfall patterns become more variable and winter temperatures rise.
Professor Mark Howden, director of the ANU Climate Change Institute, notes that the current crisis is 'a foreseeable consequence of climate change'. 'We are seeing an amplification of natural boom-bust cycles. The question is how we adapt agricultural systems to this new reality,' he says.
For now, the UK's role may be as a test bed for innovative solutions that can be deployed at scale. The Technology Strategy Board (Innovate UK) has fast-tracked funding for a consortium developing a 'smart trap' that uses infrared sensors to identify and euthanize mice selectively, avoiding non-target species. However, the cost remains prohibitive for most farmers.
Back in Australia, the immediate response is a mix of desperation and resilience. 'We're doing everything we can. We've burned fields, we've laid poison, we've even used drones to spot nests,' says farmer Sarah Mitchell from Trangie, New South Wales. 'But it's like trying to hold back the tide. Unless we get a hard frost or the rain stops, this is only going to get worse.'
The unfolding crisis underscores the interconnectedness of global agriculture and climate. As UK science seeks solutions, the real test will be whether these can be deployed quickly enough to prevent the next outbreak from becoming a permanent feature of the Australian landscape.
