Invasive Species Council calls for cull of feral horses at Lake Muir in WA

Tue 28 Jul 2026 at 8:07am

, updatedTue 28 Jul 2026 at 8:13am

In short:

The Invasive Species Council is calling on the WA government to control a feral horse population near Lake Muir.

Some locals say the horses have been in the region for generations and are less harmful than feral pigs and deer.

What's next?

The Department of Biodiversity Conservation and Attractions says it is monitoring the impacts of horse populations in the area.

Members of small farming community are questioning calls from a national conservation body to cull an "elusive" population of feral horses in an isolated but ecologically valuable pocket of Western Australia.

The Invasive Species Council is pressuring the state government to control the horse population in the Lake Muir area, about 360km south of Perth, due to road safety and environmental concerns.

"There's a pinch point right now where action needs to be taken to deal with the feral horse population," the council's advocacy director Reece Pianta said.

Brumbies are occasionally seen galloping across the Muir Highway, raising safety concerns.

In 2011 a police investigation was launched after nine feral horses were shot dead.

Loading...Manjimup Shire President Donelle Buegge disagreed there had been an increase in numbers in recent years and said there were some social media posts that might give that impression.

She said she had never personally seen a feral horse along the highway in the 20 years she had lived and worked in the region.

The ABC spoke to several farmers and community members about the call for a cull. All identified feral pigs as a more pressing issue.

Globally-recognised wetlands at risk

Lake Muir is part of the Muir-Byenup wetland system, which is one of WA's 12 critical wetlands recognised under the 1974 Ramsar Convention.

Mr Pianta said the region's feral horse management needed to mirror the approach already used to manage feral deer and pigs.

"The damage is things like soil loss, compaction, causing erosion, trampling vegetation and polluting water bodies in the area," he said.

"In general, horses are a vector for diseases, including tree-killing diseases, and this is a fairly sensitive nature reserve, wetland area which is vulnerable to heavy-hoofed animals."

Mr Pianta acknowledged there had likely been feral horses in this area for many decades but said, based on information from departmental officials and locals, that their numbers had reached unacceptable levels.

"What we have been made aware of is that over the last few decades those numbers have increased significantly," he said.

Mr Pianta is of the understanding that the horses had bred up from a small group released into the area only a few decades ago.

Conjecture on horse lineage

Seventh-generation farmer and eco-tourism operator Gary Muir recognises the environmental impact of brumbies, but rejects the Invasive Species Council's claim.

He says he has a connection, based on family history and diaries, to the brumbies dating back to the late 1800s.

Mr Muir says his great-grandfather, Robert Forest Muir, bred and tamed horses that roamed the bushland around Lake Muir, where the family resided.

"At one stage, Robert Forest Muir, there were records of him having as many as 300 horses out there," Mr Muir said.

A number of those horses were supposedly trained and sold to the Indian Army for use in the Second Boer War, and later, for the 10th Light Horse Regiment in WWI.

"They needed the remounts for the Indian cavalry and he would actually send some of his horses there," Mr Muir said.

"Some of the first horses from Western Australia for the Boer War are linked to the descendants, that are still here today, of the wild brumbies."

The ABC has not been able to independently verify a direct lineage to the current horse population.

Herd hard to track

The Department of Biodiversity Conservation and Attraction (DBCA) told the ABC it did not have a clear idea of the area's exact brumby population.

"These animals are elusive and there are no population estimates," a spokesperson said.

"DBCA is monitoring the impacts of feral pig, deer, and horse populations on the conservation estate in the area."

The consensus among locals and the Invasive Species Council puts the Lake Muir brumby population in the hundreds.

Cowaramup-based veterinarian Sheila Greenwell has rescued and rehabilitated about 30 of the Lake Muir feral horses over the years, three of which still live on her property.

She said she had been part of an aerial survey of the region just over a decade ago and had spotted between 150 and 200.

Ms Greenwell said the Lake Muir population was a fraction of the recent estimates of between 6,000 and 16,000 feral horses in Kosciusko National Park, New South Wales.

"It's a numbers game when it comes to environmental degradation," she said.

"I don't believe there [Lake Muir] that the numbers are high enough to be relevant."