The WA Department of Parks and Wildlife culled 5,118 head of cattle from conservation reserves and adjacent areas in the Kimberley last year.

At a conservative estimate, that is around $4 million worth of stock.

Parks and Wildlife regional manager Daryl Moncrieff said feral cattle were causing considerable damage to the unique Kimberley landscape, and although cattle prices were at record highs, mustering was not always an option in remote areas.

He said local pastoralists were encouraged to muster cattle out of the areas before the aerial cull began.

"We always give adjacent pastoralists the opportunity to go in and muster cattle beforehand and give them a notification at least a month in advance," he said.

"We don't want to let cattle be shot to waste, we'd rather them be mustered than shot.

"But at the end of the day, these areas are set aside for conservation as national parks, and it's in our mandate to keep them free of cattle."

The Department of Parks and Wildlife culled 526 head of cattle from the Purnululu National Park and Ord River Regeneration Reserve last year. ( ABC Rural: Matt Brann )

Economics of mustering remote areas don't add up

Mr Moncrieff said the department had sometimes paid contract musterers to work areas prior to a cull, but overall the economics often did not add up.

"Some of these areas are actually a long way from pastoral areas, and we shot a lot of cattle in the north Kimberley last year," he said.

"A lot of the areas we're shooting in are completely inaccessible, there's just not an opportunity to go in there and muster cattle.

"When you look at the economics, you'd question the viability of it."

Mr Moncrieff said the department would conduct more cattle culls later in the year.

"I think eradication is probably impossible because it is such a big area," he said.

"There will always be areas they'll infiltrate from, so it's more a matter of keeping on top of numbers to reduce the [environmental] impacts as much as we can."

Figures from Parks and Wildlife show that in 2016, the department culled 5,118 cattle, 145 donkeys, 42 horses, 90 pigs and 262 camels.

Location Cattle Donkey Horse Pig Camel Total Drysdale River National Park 1,571 122 32 - - 1,725 King Leopold Ranges Conservation Park 1,376 4 - 35 - 1,415 Mitchell River 1,645 - - 17 - 1,663* Walyarta (Mandora Marsh) - 12 - - 164 176 Noonkanbah and Millijidee (pastoral stations) ** - 4 - 33 - 37 Purnululu National Park and Ord River Regeneration Reserve 526 3 10 5 98 642 5,118 145 42 90 262 5,657

* Includes one water buffalo

** A further 220 horses were culled at Noonkanbah and Millijidee, as a service arranged through the Regional Biosecurity Group.

Source: WA Department of Parks and Wildlife