The Western Australian Government has spent millions on eradicating more than 500,000 feral donkeys from the state's far north over the last couple of decades.

One of the last remaining herds in the Kimberley, located on Kachana Station, is now in the sights of aerial shooters.

However the owner of Kachana, Chris Henggeler, says he does not want the donkeys killed.

'Don't shoot' says Kachana

Kachana Station is currently using wild donkeys — about 100 of them — in a scientific land management trial and is calling on the Government to pause and consider the commercial value of the animals.

"Rather than awaiting scientific evaluation of this project they've decided that our donkeys must all be shot," Mr Henggeler said.

"We're getting scientists in to study these donkeys and what we're finding is that all wild animals have a function out there in the landscape and we can actually influence those functions and enhance the health of the ecosystems.

"We believe we've demonstrated they're a useful land management tool and it doesn't make sense to be spending money when they could be part of the solution."

Mr Henggeler said the donkeys were living in rough terrain where cattle did not readily venture and were helping the ecosystem in a number of ways, including their role in keeping grasses low, which he said reduced the risk of out-of-control wildfires.

Time is running out

In a letter sent to Kachana at the start of this month by the Kimberley Rangelands Biosecurity Association, the Henggeler family were told the donkeys needed to be culled either in a "one off" shoot this year, or a 25 per cent reduction cull each year for the next four years.

"Our firm conclusion is that we are unable to support the use of a declared species, in particular donkeys, in any way as a landscape management tool," the letter said.

"As you are aware we are in the final stages of our donkey eradication program in the Kimberley and we believe this program will greatly benefit both landholders and native species' biodiversity within the Kimberley region."

Donkeys grazing on Kachana Station in the Kimberley. ( Supplied: Kachana Station )

Mr Henggeler said the Government should terminate its donkey culling program and support the research on Kachana.

"What might have made sense 30 years ago doesn't make sense now," he said.

'The [donkey] population back then; something needed to be done. They did need to be managed but they are [under control] now.

"We would like to see some sound, ecological decision making."

Donkey policy differs between WA and NT

Adding to Mr Henggeler's frustration is that across the border in the Northern Territory the Government has started investing in its own donkey research program.

"It seems in the Northern Territory this animal has got a value, but on this side of the border we're using tax payers' money to try and blow out the last few [donkeys] we can find."

A statement from the WA Government said feral donkeys have "significant impacts on pastoral and environmental assets of the northern rangelands in WA".

"Feral donkeys are a declared pest under the Biosecurity and Agriculture Management Act (2007) and under the Act it is the landholders' responsibility to control declared pests," the statement said.

"The Department of Primary Industries and Regional Development has qualified officers who work with the Kimberley Rangelands Biosecurity Association to deliver their feral donkey control program in line with their operational plan."