Herds of wild horses running free through Kosciuszko National Park have provoked ferocious debate between ecologists and advocates.

On one side, those demanding a cull say native flora and fauna are being irreparably damaged and the animals are a pest.

But then there are those who want the brumbies left alone, with many staunchly defending them as a national icon.

A dedicated group of horse trainers has tried to straddle the fence.

They want to reduce wild horse numbers while also giving the animals a useful life.

Mustering support for the middle ground

Competitors in the Australian Brumby Challenge have 150 days to tame a feral brumby, passively trapped from the wild.

Horse and trainer are judged at a final showing in Victoria before the animals go to auction.

There's a clear commercial incentive for those who want to showcase their abilities as a trainer.

But it is also a passion project for Lauren Woodbridge, who took charge of four-year-old mare Lark.

"It doesn't really take that long to make something incredible," she said.

"I want to see Lark out there with a wonderful new home, making new friends, and achieving everything that she can achieve.

"If the brumbies are seen as useless, then it's really hard to rehome them or to get them to suitable people that will actually use them."

Lauren Woodbridge's efforts mean she can trust her brumby Lark with anything. ( ABC Canberra: Michael Black )

Ms Woodbridge has observed years of inaction when it comes to managing horse numbers in Kosciuszko National Park.

This year the New South Wales Government backflipped on a plan to cull 90 per cent of wild horses in the area.

A so-called "Brumby Bill" was instead put forward, which enraged many ecologists for seeming to ignore science in favour of popular opinion.

It introduced new protections to the wild horses based on their perceived cultural significance.

Ms Woodbridge said both sides of the debate were fired up, with neither willing to compromise.

"You're never going to take all the emotion out of this situation.

"Both groups are at each other's throats, thinking the other has had every opportunity to do the right thing and failed.

"When, really, everything has been wrapped up in red tape and no one's had a chance to prove themselves and do anything."

Some brumbies become tame enough to thrive in any kind of environment. ( ABC Canberra: Michael Black )

The search for compromise

Horse trainer Mick Mason from Braidwood, New South Wales said he was not against culling, but admitted he would rather see horses humanely captured and rehomed.

That is part of what spurred him on to enter the challenge — to showcase the practical value of such animals.

But he said prospective owners needed to be capable of caring for the high-maintenance animals, otherwise the problem would only grow.

"It can be done on a bigger scale … once they see how trainable they are," he said.

"But those people that care about them and know about horses, need to be responsible.

"They can only take what they can take."

Mr Mason spent the past few months taming a stallion called Coolabah at his property near the border between New South Wales and the Australian Capital Territory.

If a wild horse like Coolabah should cross into the Territory's jurisdiction and become trapped, it can be euthanased by rangers.

"He's too clever to be shot. He's a great little horse," Mr Mason said.

"I do believe that I am somewhere in the middle of the two sides.

"I support the proper management of the brumbies … but I do not support aerial culling because it needs to be done humanely."

Mick Mason's brumby Coolabah was originally captured in the Kosciuszko National Park. ( ABC Canberra: Michael Black )

Scientists fed up with inaction

This week more than 50 leading ecologists met in Canberra to speak out against the NSW Government's policy reversal.

Dr Jamie Pittock from the Fenner School of Environment at ANU said it went blatantly against scientific evidence.

"It's just appalling. It's not what Australians expect of our political leaders," he said.

"It's only NSW that's failing to be a responsible land manager and control feral horses in its national park."

Dr Jamie Pittock represents dozens of scientists outraged over inaction around wild horse management. ( ABC Canberra: Michael Black )

He estimated there were now 7,000 wild horses causing damage in Kosciuszko National Park.

With numbers that high, he said there was no chance of a compromise over culling.

Dr Pittock also dismissed passive trapping measures and rehoming due to the small numbers of horses captured.

"Nobody likes shooting such magnificent animals," he said.

"But the reality is that the program of capturing live feral horses isn't working.

"Only 18 per cent of the horses caught live are able to be rehomed. The rest end up in an abattoir."

A new accord signed at the Kosciuszko Science Conference will be presented to the NSW parliament in coming weeks.

Ms Woodbridge was hopeful a compromise could still be reached between scientists and her fellow brumby advocates.

She said their goodwill should be better embraced by ecologists, with many volunteers eager to transition into paid work.

"You've got a huge body of people willing and able to spend all their time in the national parks," she said.

"Instead of trying to beat them — use them."

The Australian Brumby Challenge takes place on 15-18 November at the Melbourne Showgrounds.