After the cull: How Kosciuszko is slowly stirring back to life

A survey of feral horse populations in Kosciuszko National Park has found the number of animals left in the park after a controversial aerial culling program is anywhere between 1579 and 5639, as experts find signs of ecological recovery since the cull.

Before the aerial culling began, between 12,797 and 21,760 horses were estimated to be in the park. A total of 9036 horses were removed from the park between November 2021 and April 30, 2025, using ground and aerial shooting as well as trapping and rehoming. Of those, 5969 were shot from the air.

The National Parks and Wildlife Service (NPWS) conducted two parallel surveys using different methods after the aerial culling program to both test new methods while ensuring comparable data sets were maintained.

One survey, using a method known as standard-distance sampling, estimates with 95 per cent confidence that the population in the survey area is between 1579 and 4007 horses. The second, using mark-recapture distance sampling, estimates the number to be between 2131 and 5639 horses. A thermal camera survey was also tested.

NSW Environment Minister Penny Sharpe, who visited key sites in the park in July 2023 and again on May 10 this year, said the recovery of the landscape was dramatic, with areas that had been turned to either mud or compacted earth now covered with grasses, while streams were running clear.

“Visiting those sites was for us, and I think for the team and for the National Parks people as well, is a moving experience. It just gives you hope that doing hard things is worth it because it actually pays off,” Sharpe said.

“It was something that I never wish that we had to do, but it was really clear that the numbers were too high, and the damage that the horses were doing to the park was not something that we would tolerate in any other national park.”

She said the cull was particularly hard on NPWS staff, many of whom came under significant pressure in their communities as the controversy mounted.

“You’ve got to remember, someone put a severed horse’s head at the front door of the Jindabyne Visitors Centre.”

NSW Environment Minister Penny Sharpe inspecting recovery from damage caused by wild horses in Kosciuszko National Park.

The adoption of aerial culling was fiercely opposed by some animal rights activists and local brumby advocates who see the feral horses as a living link to the region’s colonial history. A law championed by former NSW Nationals leader John Barilaro compels the NPWS to ensure 3000 horses remain in a so-called horse retention area in the park by 2027.

Based on the latest surveys, the NPWS believes that obligation will be met.

ANU ecologist Dr Jamie Pittock, who has also visited the key sites in the park seen by Sharpe, confirms signs of recovery are clear.

He said he had seen muddy banks now covered in grasses, not only helping to keep water clear for endangered fish and crayfish species, but providing habitat for the endangered broad-toothed rat – “kind of an Australian hamster” – which lives in tunnels in the undergrowth by the streams of the high country.

Areas that had been reduced to mud or sun-baked bare earth are now spongy underfoot, said Sharpe. Pittock said this was a crucial change. “It means that rainfall is more able to infiltrate into the soil and be stored in the subsoil, and that means that soil moisture is able to sustain plant growth. It makes it better habitat for all the smaller animals that live there.”

But he said it would take years to undo some of the damage. The sphagnum moss bogs that can grow to waist height, and provide home to animals like the corroboree frog, can take decades to recover, he said.

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