Australia’s feral horses need ‘urgent’ control: scientists welcome latest report

Ecologists are welcoming recommendations from the Australian Senate to strengthen legal protections for wildlife threatened by feral horses in the Australian Alps, where they are harming vulnerable species and a unique and delicate ecosystem.

Many scientists say that culling feral horses (Equus caballus) is necessary to prevent environmental damage and the extinction of species. But conflicting state and federal government laws have allowed the growth of a 25,000-strong population of feral horses across the Australian Alps region in southeast Australia, including within designated national parks. “If feral horse populations are not urgently managed, there is a real risk of losing this unique landscape and the native species that call it home,” the report states. It was released on 13 October by the senate standing committee on environment and communications, who began an inquiry on the impact of feral horses in February.

The guidance includes a recommendation to recognize the threat that feral horses pose as a ‘key threatening process’ in the national Environment Biodiversity and Conservation Act (1999). It also calls for additional monitoring and assessment of the damage that feral horses are causing, and the resumption of aerial shooting of feral horses in New South Wales (NSW), where the method is currently banned. The recommendations mark the first time that the federal government has weighed in on the issue.

Urgent action required

“I am extremely pleased to see the senate recommend that the federal government needs to take urgent action on a whole range of fronts to try to undo the ecological disaster that feral horses have been allowed to become,” says Don Driscoll, an ecologist at Deakin University in Melbourne, Australia. He adds that the recommended boost to funding for better management of the problem is “among the most important” of the recommendations.

But some ecologists and policy experts say the recommendations don’t go far enough. Thomas Newsome, an environmental scientist at the University of Sydney, Australia, says that while the report acknowledges the urgency of the situatiuon, “many of the recommendations and steps will take a considerable amount of time to achieve”, especially given the proposed changes to legislation. Improvements “on the ground” will require considerable effort and a willingness to fast-track the key recommendations, he adds.

Sarah Clement, an environmental policy researcher at the Australian National University in Canberra, Australia, says that it is unclear whether adding feral horses to the national list of key threatening processes will make any difference to management. Such listings “haven’t been used in many cases to date to trigger action”, she says. “It’s not clear if or how they would here.” She also notes that horse are in fact already included in the key threatening processes list under ‘novel biota and their impact on biodiversity’.

Soaring populations

Europeans introduced horses to Australia in the late eighteenth century. But feral horse numbers in the Australian Alps — which stretches across NSW, Victoria and the Australian Capital Territory (ACT) in the southeast of the country — have soared over the past two decades.

That is increasing pressure on the delicate alpine ecosystem, where flora and fauna did not evolve to withstand the presence of large, hard-hoofed herbivores. “There are areas that should be lush with tall tussock grasses and streams,” says Driscoll, who has studied the effects of the feral horses in the Alps¹. Now, these areas look like heavily grazed paddocks.

“We have to act on this now. Because the problem is rapidly getting much, much worse,” says Christopher Johnson, a conservation biologist at the University of Tasmania in Hobart, Australia.

Feral horses are a danger to 12 of 14 species of vertebrate already deemed at risk of extinction in the Alps, including the northern and sourthern corroboree frogs (Pseudophryne pengilleyi and P. corroboree), the alpine she-oak skink (Cyclodomorphus praealtus) and four species of Galaxias fish. “Horses might be the thing that makes them finally go extinct,” says Johnson, who is also a member of the national threatened species scientific committee.

But some community groups, as well as a dissenting report by senators of the conservative coalition government, maintain that wild horses — known locally as brumbies — have roamed the region for decades and belong there as a part of Australia’s cultural heritage. NSW’s Kosciuszko Wild Horse Heritage Act, passed in 2018, requires horses to be protected at a sustainable level.

In additional comments tabled in the report, David Pocock, the independent senator for the ACT who instigated the inquiry, called for the repeal of the Act, which he says presents “the biggest threat to the Australian Alps”. He also recommended that NSW and Victoria adopt the ACT government’s “zero-tolerance” approach to feral horse management.

Management mismatch

In Australia, most national parks are controlled by state and territory governments. So far, the management of feral horse populations has been left to them, despite the federal government being responsible for stopping invasive species and protecting vulnerable ones.

The ACT has eliminated feral horses from its national parks, killing horses that stray in from NSW, and rangers in Victoria’s national parks, which have around 6,000 horses, have reduced numbers by capturing and rehoming the animals, or by shooting them on the ground. But in NSW’s Kosciuszko National Park, control methods have been inadequate, especially in its inaccessible northern areas. The park counted 18,000 horses in 2022, the largest number and highest density in the Alps and a huge increase from the 2,000 counted in 2003.

A state management plan put it in place in 2021 required Kosciuszko National Park to reduce numbers to 3,000 by 2027. But modelling obtained by the Invasive Species Council, a charity in Katoomba, Australia, estimates that this reduction would require the removal of almost 6,000 horses per year. The park is currently removing just 1,000 horses a year — meaning that the population could hit 33,000 by 2027.

The latest guidance from the federal government is non-binding. But scientists and conservationists hope that it will spur stronger, more unified action across the states to stop the damage caused by the horses, and pave the way for strengthened federal legislation to limit the spread of invasive species and prevent the extinction of native flora and fauna.

Aerial culling

Scientists are applauding the report’s recommendation that NSW’s wild horse management plan be updated to allow horses to be shot at from helicopters. NSW banned the practice after an incident in 2000 when a horse was found injured but alive five days after an aerial cull.

Many researchers say that aerial culling is the best tool available for controlling horse numbers. In the vast, rugged landscape of the Alps, measures such as ground shooting or trapping and removal are less effective and too expensive, says Jack Gough, advocacy manager at the Invasive Species Council. “The horses are in such high numbers and they’re in places that are hard to get to,” adds Driscoll. A study on the effectiveness of sterilizing female horses found that it would take between 10 and 20 years for horse numbers to fall².

Aerial shooting is used to control horses and camels in Central Australia, as well as feral deer in NSW, notes Newsome. A 2017 study of aerial shooting of horses and camels in Central Australia found that most horses died instantly³. Even before today’s guidance was announced, NSW was considering allowing aerial shooting of feral horses.

Community support for aerial shooting is crucial, says David Berman, an ecologist at the University of Southern Queensland who served on the scientific advisory panel for the Kosciuszko Wild Horse Management plan. Without broad support, he adds, there could be another backlash against the horse cull, which could jeopardise the use of aerial shooting of horses elsewhere in Australia. “It could be a disaster,” he says.

Some scientists say that the latest guidance is just the beginning of what now needs to happen. Gough says that NSW’s Kosciuszko Wild Horse Heritage Act should be repealed so that horses can be controlled more aggressively.

But he says that “unless aerial shooting is approved by [NSW Environment Minister Penny] Sharpe, and federal [Environment] Minister [Tanya] Plibersek is prepared to stump up serious funding, all this talk will not make a difference to the rapidly rising feral horse population.”

Source: Ecology - nature.com