Just after dawn a blood-curdling howl tells Glen Coddington that the dingo is close.

Peering from his kitchen window, he spots a large yellow dog gliding in the shadows along the perimeter of the high-wire fence to the north.

Quickly and silently, like a trained assassin, Coddington pokes the barrel of his high-powered rifle through the window and at a range of 150 metres, levelled the crosshairs of his target and fires.

The dingo drops, instantly dead. The veteran hunter has claimed another scalp to go with the half a dozen hanging in his shed.

When we arrive soon after the dingo’s pelt, scalped from nose to tail, he hangs on a wire hook suspended from a tractor cabin.

“You missed the drama,” chides Coddington gently.

“I shot a big dog just before. And what’s worse it was on my side of the fence.”

Wild dogs on the southern side of the fence are a rarity but they exist and this one, evidently lovelorn, had been foolishly and fatally attracted by the presence of Coddington’s large pig dog bitch enclosed within the high tin fence surrounding his modest fibro-cement house.

Coddington is a maintenance man for the Great Barrier Fence, usually called the dog fence.

Its aim is to exclude Australia’s native dog - the feared and destructive enemy of the sheep farmer – from entering the vast rangelands and pastoral zones of New South Wales.

“If they didn’t have this fence I think there wouldn’t be a sheep in New South Wales, so it’s very important,” says Coddington, one of a dozen workers stationed at outposts along the entire length of the 1.8-metre high fence and responsible for its upkeep.

Fence worker Glen Coddington shows off a dingo pelt from an animal he had shot. ( ABC News: Tim Lee )

At 5,600 kilometres long, the dog fence is the longest barrier in the world. It begins on the Nullabor Plain near the Western Australian border, meanders through South Australia’s arid north, delineates the border between New South Wales and Western Queensland and finishes on the Darling Downs.

The fence has never been more topical. A run of good seasons has allowed wild dog numbers to build up on both sides of the fence.

Graziers, striving to re-build stock numbers after a decade-long drought, are reporting increased number of dingoes.

South Australia has recently carried out a trial of aerial baiting in the north of the state to curb large dingo numbers, while recent flooding and water logging along the fence have weakened its defences. Feral pigs especially have been forcing holes in the netting, raising the threat of wild dog incursions.

“You’ve got to be pretty capable. You get a lot of challenges at times,” says Coddington of his isolated existence.

“A bit of mechanic work and a bit of welding, so you’ve got to have a few skills. But it’s a good job.”

Driving alongside Australia's 5,600km dog fence in far-western Queensland. ( ABC News: Tim Lee )

Coddington is based at Hamilton Gate, a mere pin prick on the map at the junction of several unsealed roads. His nearest neighbour is 70 kilometres away and a fortnight might pass without him seeing another human.

His wife sometimes finds the isolation imprisoning and heads to a regional town for a break. But ‘Moc’ Parker, Coddington’s dog fence colleague based at Hungerford to the east, never feels overpowered by the solitude and the hundreds of kilometres of dusty roads that he travels in his daily work.

“I’m pretty lucky I live in a town that’s got seven people in it,” says Parker, who has spent his entire working life in the outback.

“I can always find someone to say G’day to, but poor old Glen out here, unless his wife’s with him, he spends a hell of a lot of time on his own so he’d really have to knuckle down to be used to a bit of isolation.

“It’s not something that everyone would want to take on I wouldn’t think as a job.....You’ve really got to want to be here and accept where we are."

Coddington has long become accustomed to life in one of the nation’s loneliest and remotest outposts.

“I like being in the bush, that’s mainly why I came out here. Country lifestyle’s really good. I don’t mind being by myself, so it’s quite interesting really being out here.”

Once dried, he’ll take this morning’s fresh scalp and his other grisly trophies to the nearest Department of Primary Industries office to claim his reward - a modest bounty of $10 per scalp.

“Not much. But it adds up,” muses Coddington.

It’s simply part of the price of eternal vigilance along Australia’s famed Dog Fence.