European rabbit populations are booming across Australia following a wet winter in central and southern regions, driving an ecological crisis that threatens hundreds of native species and costs the agricultural sector $200m annually, according to the Centre for Invasive Species Solutions (CISS).
The invasive pests (Oryctolagus cuniculus) are multiplying rapidly in peri-urban areas, regional farmlands, and remote conservation reserves. While working dogs flush rabbits from the landscape and detect warrens, local councils deploy professional shooters, scientists warn that traditional biological controls are losing their effectiveness against resilient rabbit strains.
The Rabbit Surge on Conservation Reserves and Farms
In South Australia’s arid centre, a five-year-old kelpie-jack russell-whippet cross named Jojo runs up to 20 kilometres a day across the Bon Bon Reserve. According to Dr Pat Taggart, an ecologist with Bush Heritage Australia, Jojo works eight days on and two days off to scare rabbits back into their burrows so staff can locate, map, and fumigate or rip up the warrens.
Recent rains have turned fresh shoots of native plants like acacia and mulga into breeding fuel for the pests. This population explosion at Bon Bon and the Boolcoomatta reserve to the east mirrors conditions nationwide, according to CISS director of research, development and engagement Dr John Virtue. Virtue highlights severe hotspots in southern Western Australia, suburban Canberra, peri-urban Adelaide, the New South Wales Riverina, and southern Queensland.
In Albany, southern Western Australia, plague-level rabbit populations have invaded farms and a local golf course. Greens staff have battled to fill holes dug by dozens of rabbits gathering each evening, which Virtue notes leaves the landscape denuded.
Historical Spread and Economic Impact
Though introduced during the British invasion in 1788, researchers trace Australia’s continent-wide rabbit plague to 24 rabbits brought by settler Thomas Austin in 1859. By the 1920s, populations reached billions, while modern estimates place the number near 200 million amid a lack of formal monitoring.
A past study cited by researchers found that rabbits negatively impact 329 threatened Australian species, surpassing every other invasive pest. When food is plentiful, reproduction occurs throughout the entire year, whereas temperate regions experience breeding peaks during both the autumn and spring seasons following precipitation events. If left alone, a rabbit population can increase tenfold in one season. A 2020-2021 estimate suggested rabbits cost the Australian agricultural sector $200m a year.
Furthermore, rabbits create a dangerous triple threat by sustaining high densities of feral predators like cats and foxes. According to Prof Katherine Moseby, an ecologist and conservation biologist at the University of New South Wales, rabbits act as the key driver in maintaining these predator populations.
Biological Controls and Evolving Resistance
Broad rabbit control historically relied on two introduced viruses: myxoma in the 1950s and versions of calicivirus from the 1990s. The accidental 1995 escape of calicivirus from Wardang Island in South Australia slashed arid-zone rabbit numbers by as much as 95%. Moseby describes that event as causing probably the biggest recovery of threatened species ever recorded in Australia, with small mammal populations surging as rabbit densities dropped from 150 down to two per square kilometre.
However, those viruses are now losing potency. "Over time, the rabbit hemorrhagic disease virus has been losing its effectiveness," Virtue says, emphasizing the need to release new strains every ten to 15 years. The federal government announced a program in July to develop new variants of the calicivirus.
Did You Know?
Research traces Australia’s continent-wide rabbit infestation back to just 24 rabbits imported by settler Thomas Austin in 1859.
Peri-Urban Reservoirs and Local Control Measures
Urban and peri-urban areas pose a distinct challenge for rabbit management. Wayne Meyer, an expert affiliated with the Foundation for Rabbit-Free Australia and an adjunct professor of natural resource science at Adelaide University, explains that these locations function as reproductive reservoirs where the animals find shelter beneath structures and among plantings before migrating into adjacent farmlands.
In Mount Barker, east of Adelaide, thermal cameras detected dozens of rabbits grazing on sports fields after dusk. Susan Ivory of the Hills and Fleurieu Landscape Board notes that local professional shooters bag more than 100 rabbits in a single night, while regional poison sales increased fivefold over a four-year period.
Landholders currently rely on fencing, poisoning, warren ripping, fumigation, and licensed shooting. CISS guidance notes that ground shooting ranks among the most humane control methods, while certain poisons are among the worst for animal welfare.
Pro Tip for Landholders:
According to landscape boards and pest control experts, coordinated community action—such as neighboring housing estates simultaneously deploying baiting and warren destruction programs—yields significantly better results than isolated control efforts.
Frequently Asked Questions
Why are rabbit numbers increasing in Australia?
Rabbit numbers surge following wet winters and spring rains that provide abundant green shoots from native vegetation, supplying the food and breeding fuel necessary for populations to multiply rapidly.
What methods are used to control rabbits?
Landholders use a mix of biological controls like calicivirus, physical methods such as fencing and warren ripping, fumigation, poisoning, and professional shooting. Trained detection dogs like Jojo also help locate warrens.
How do rabbits impact native wildlife?
Rabbits denude native landscapes, compete with native species for food and shelter, negatively impact 329 threatened species, and sustain high populations of introduced predators like cats and foxes.
Are biological controls still effective?
Viral strains such as the rabbit hemorrhagic disease virus have lost effectiveness over time as rabbit populations develop genetic resistance, prompting research into new virus variants.
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