Colleen Krestensen, Deputy President of the Australian Brumby Alliance, and proud owner of two beautiful rehomed Snowy brumbies, June 2026.

The NSW Environment Minister, Penny Sharpe, released new estimates of brumby numbers in Kosciuszko National Park (KNP) on 22 May 2026,¹ which implied a dramatic and biologically impossible population increase of up to 315 per cent over a 12 month period from the previous year’s survey results.  An increase of this size, when fertile mares only have one foal a year, simply doesn’t pass the pub test or objective scientific scrutiny. And it certainly can’t be explained simply by a mild summer resulting in higher foaling rates as some ecologists have suggested.

The concern for the community is the government is accepting this alleged increase without question as a basis to resume aerial culling brumbies, commencing in the coming days.  In a debate which sometimes has been pitched as science versus sentiment, science is on the side of the brumbies this time.

An unbelievable increase in brumby numbers

The 2024 survey of wild horse numbers in the KNP, released in 2025, estimated a range of between 2,800–3,950.² The government drew from this report a central estimate of 3,949 horses.  The recently released 2025 survey report estimated a range of 6,476–16,411 brumbies, with a central estimate of 10,309 horses.  Some increase in numbers is possible. However the alleged increase based on central estimates is around 160 per cent.  The increase based on top of the range numbers is over 315 per cent. 

It simply is not possible for the population to have increased anywhere near these numbers even if every mare produced triplets.  Horses reproduce in the wild at a rate of between 7 per cent and 15 per cent, unlike wild pigs, foxes or cats which produce litters and can spread quickly, and more neatly fit common definitions of an invasive species which generally include rapid reproduction as a key characteristic.

Both survey reports were the subject of a peer review process. Analysis of the peer reviews, of the most recent report on the 2025 survey, reveals concerns that the methodology may have contributed to the significantly higher numbers.  Reviewers respectfully noted, for example  that the survey method “quite possibly inflates” the population estimate.  They also noted that the direct extrapolation of average numbers from surveyed areas into terrain which was not possible to survey due to steepness or dense vegetation was “almost certainly wrong”, given the likelihood of lower numbers of horses in these area.³ The name of the organisation which undertook the survey was not publicly released by the government. 

What about the apparent recovery of the Kosciuszko National Park after the removal of so many horses?

The survey also seems at odds with the feedback from National Parks and Wildlife (NPWS) about recovery in the KNP after the reduction in horse numbers.  NPWS advised in May 2026 that 9,198 wild horses have been removed from the Park since 2021, 6,041 of which by aerial shooting.

We’ve seen a number of reports and photographs on social media from NPWS and from the Invasive Species Council suggesting the KNP was recovering well and looking in great shape after the significant reduction in horse numbers.  This suggests, like many of us who visit the mountains, that they thought numbers were down, not up.  We have seen no recent evidence of damage from dense numbers in particular locations, other than photos recycled from many years ago, most of them from the 2020 drought when horses gathered around the waterways. We can only assume they were also quietly surprised by the survey results. 

Simply the result of a mild summer in the mountains?

Ecologists from Charles Sturt University and Sydney University who are arguing for recommencement of aerial culling have suggested in The Conversation of 1 June 2026 that the increase can simply be explained by “a mild summer” with significant rainfall during which most mares will have bred. ⁴ This argument definitely fails the biology test.  Even a 20 per cent increase, which is very high for wild horses,  would only result in an additional 800 horses, not the 6,500 horses required to reconcile the two survey reports. They have also suggested horses were coming into the KNP from nearby state forests or moving within the park. While it’s possible there may have been some movement of horses who previously fled the bullets, there appears to be no evidence on the ground of large numbers travelling into the KNP.  Thousands of new horses suddenly appearing in the park would have been noticed and the subject of public comment by NPWS and by those who photograph brumbies in the KNP. 

Resources for rehoming, not bullets

Brumby advocacy groups do not dispute there may have been some increase in numbers.  However, the maximum increase possible over a 12 month period could reasonably be expected to be in the hundreds not thousands, and manageable by humane alternatives to aerial culling.  Minister Sharpe has promised a trial of fertility control.  The Australian Brumby Alliance (ABA) welcomes this promise and supports future exploration of fertility control for the brumby population.  However ABA points out that passive trapping and rehoming is an immediately available humane alternative to the aerial cull.  Unlike other introduced species in the KNP, there is a non lethal alternative to management.  Horses can be easily domesticated and have value to the community.  Through the rehoming pathway, brumbies passively trapped are assigned to registered rehomers from whom, usually after some early handling and care, they go to sanctuaries or private homes.  ABA is deeply concerned that despite the NSW Government investing over $8.2 million in aerial culling, there’s been no government investment to support rehoming.⁵ 

Jenni Cole from Umbango South Brumby Sanctuary, the home of the famous brumby stallion Posterboy,  asks “Why are there millions of dollars allocated by the government to killing these horses, when the non-lethal pathway – rehoming and sanctuaries – has never been properly supported or taken seriously? Rehoming has been around since long before there was a National Park. It’s part of our history and our heritage and it is the solution Government is ignoring.”

The Australian Brumby Alliance supported by Umbango South and other registered rehomers put a proposal to the NSW Government for a modest investment in rehoming to expand and support the role the sector plays as a humane alternative to aerial culling before this most recent survey report was released.  We aren’t looking for additional spending by government – just a better use of existing funding for wild horse management to achieve more humane outcomes.  There is more interest than ever in the community in rehoming a brumby to support this pathway. We are still waiting to hear back from Minister Sharpe’s office. 

Related stories: Is there a future for the Snowy Mountain brumbies?, brumby.

References
1. NSW National Parks and Wildlife Service (2025), Kosciuszko National Park Wild Horse Population Survey 2025: Abundance Estimates and Methodology, NSW Department of Climate Change, Energy, the Environment and Water.
2. NSW National Parks and Wildlife Service (2024), A survey of the wild horse population in Kosciuszko National Park, NSW, October-November 2024, Report to the NSW Department of Climate Change, Energy, the Environment & Water, November 2024.
3. NSW National Parks and Wildlife Service (2026), Draft Kosciuszko National Park Wild Horse Population Survey – Peer Review Correspondence.
4.“Feral horse numbers in Australian alps are on the rise again.  It’s time to act”, The Conversation, 1 June 2026, David M Watson and Patrick Finnerty.
5. Minister’s evidence, NSW Legislative Council Animal Welfare Committee, 31 July 2024.