It is the toughest kind of PR campaign to run: convincing Australians the wild horses of the Snowy Mountains, made famous by Banjo Paterson's The Man from Snowy River, need to be urgently shot.

And some of Australia's leading ecologists accept the campaign is currently failing.

Dozens of scientists today signed a new accord, calling on the New South Wales Government to overturn the so-called Brumby Bill which handed new protections to the wild horses in the Kosciuszko National Park based on their cultural significance.

But with the push comes a need for the scientists to find a message that will bring the public on side with the cull.

Scientists acknowledge cutting through the jargon to appeal to the public is not always their greatest strength, and evocative images of men shooting horses out of helicopters can be far more potent than calls to save the corroboree frog or broad-toothed rat.

Scientists signed an accord calling on the NSW Government to act. ( ABC Open contributor Michelle J )

But Dick Williams from Charles Darwin University said it was clear ecologists need an emotionally engaging message of their own.

"What science has to do, is to sell the beauty of the Australian alps," Dr Williams said.

"They are an extraordinarily beautiful national asset, And the sad fact is, any kind of livestock trashes that beauty"

Aerial culling 'the only option'

The announcement of the Brumby Bill came as a shock to many in the scientific community.

The Australian Academy of Science wants a dramatic reduction in the number of horses in the national park, and says aerial culling as the best possible means of doing so.

Jamie Pittock, from the Australian National University, said it may not be pleasant but it really was the only option.

Scientists say aerial culling may be the "most humane" option. ( ABC Open contributor Judy Goggin )

"The only effective way of reducing horse numbers to a level that will reduce the environmental damage is aerial shooting," Dr Pittock said.

"Now that doesn't always appeal to some people in the population, but it is actually the most humane way of dealing with wild horses."

The last time aerial culling of wild horses took place in New South Wales was in 2000, when more than 600 horses were culled after a bushfire in Guy Fawkes National Park.

The public condemnation that followed meant it was never seriously considered again, though later reviews found the cull was justified and carried out appropriately.

Don Driscoll from Deakin University said it was time for that position to change.

"While [aerial culling] does have some animal welfare concerns, they can be minimised by using appropriate culling methods and trained shooters," Professor Driscoll said.

"We also need to weigh up those animal-welfare issues with the consequences of not culling."

But Madison Young from the Australian Brumby Alliance said aerial culling would not be tolerated by the broader community.

"Members of the public just don't agree with aerial culling," she said.

"Because they expect that our wildlife — regardless of introduced or native — will be treated humanely."

NSW opposition would 'repeal bill'

Taking a political stand is also an uncomfortable position for many scientists, particularly in the context of an upcoming state election.

NSW Labor promised to repeal the 'Brumby Bill' if elected, but maintained a ban on aerial culling.

Advocates for brumbies said they were not opposed to removing horses from the National Park where necessary, and they felt the Brumby Bill struck the right balance.

They say methods like trapping and removing horses, and fertility control, should be the primary approach.

Deputy Premier John Barilaro, who pushed the Brumby Bill, said it did not end the use of population control for wild horses in Kosciuszko.

"The Bill, which was introduced only months ago, has not changed the status of the Brumby to 'protected', nor has it changed existing population-control operations," he said.

"It has maintained a ban on aerial shooting of wild horses which has been in place for nearly 18 years.

"Nobody wants to see horses shot from the sky and left dying for weeks as was the case in Guy Fawkes National Park in 2000.

"The Wild Horse Management Plan, which will be implemented in coming months, aims to find a balance between humanely controlling the Brumby population and preserving sensitive areas of the National Park."