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.