New technology plays a large part in the modern day battle to eradicate wild goats.
But Brin Barron says it is still a simple game for hunters - find the animal and shoot it.
And, after a lifetime of controlling the feral pests, the results are satisfying.
"You go up the Dart Valley now and see shrubs and trees you'd never see when animals were at their thickest. You could be in the bush in the 1970s and see nothing on the ground because the vegetation was all eaten.
"Now, you can't see beyond 5m in selected places because the diverse natural vegetation has regenerated, which is the habitat of native birds and insects. The true nature of the forest has come back [to the way it was] before grazing animals came in."
Mr Barron began his career aged 16 as a seasonal hunter, working for the New Zealand Forest Service.
The service employed hundreds of hunters in a bid to control introduced pests.
"I started at a woodsmans school in Dunedin, where you learned all silviculture skills and in that regime was an area where you were taught to keep pests away as trees grew up.
"Some guys were keen on being a general forester, but I was more interested in animal control. I just enjoyed the hunting and the outdoor life and matching your wits with the animals.
"You were given a lot of independence and freedom."
Aged 18 and certified as a woodsman, Mr Barron and three colleagues were assigned to Port Craig, on the south coast of the Fiordland National Park, for six weeks.
A superviser enhanced their bush survival skills in a wet climate, and they learned how to read the weather and rivers, ration provisions and hunt for food, while opening walking tracks and maintaining huts.
"That confirmed the choices I made. It had its moments, when you'd rather be home with a warm shower, but they were few and far between," Mr Barron said.
The first-grade hunter took a year-long Forest Service assignment in Te Anau - an attraction being its wealth of wapiti, regarded as the prime trophy animal at the time.
Venison recovery introduced the use of helicopters to harvest deer and process venison for the European market in the early 1970s, which shifted hunters' priorities to goats and other game without commercial interest.
"The Forest Service was setting up an animal control centre in Queenstown in 1970, so I asked one of the managers to put my name at the top of the list," Mr Barron said.
Parts of the Lakes district were overrun by thousands of goats that had bred without control since the "horned rabbits" were introduced by gold-miners.
His job was to assess the wild animal population, decide if control was needed, then find hunters and resources to tackle the problem.
Mr Barron surveyed the Dart Valley on foot in a month, the Rees Valley in two weeks and the Shotover in two months.
"They had a lot of goats that had spread from the Shotover to Mt Aspiring National Park. The Dart, and Dart and Rees valleys were suffering the most.
"The deer had eaten all the palatable vegetation and the goats followed the deer. Because they are more agile, they eat all the sections that were left."
Mr Barron returned to the Wakatipu in 1977 after three years' hunting in Blenheim and Te Anau.
He said controlling the goat population was inconsistent, because government funding was inconsistent.
"It wasn't until 1990, after Doc formed, that we had a proper strategic programme that shot goats and was linked to conservation values that the scientists had written up and justified we'd have a result in five or 10 years' time."
The Remarkables, Eyre Mountains and Mt Aspiring became the top priorities for controlling goats, but Mr Barron was one of only six hunters tasked with patrolling the vast areas.
"The best we ever done was 700 goats in three hours' flying time, in the Shotover, in the early 1990s. That's with two of us in a chopper using 12-gauge shotguns at close range, about 15m from the target."
Mr Barron felt Doc was having an effect on goat control by 1993 and could tell by his surveys of native bush regeneration.
The "Judas goat" technique was a watershed moment in New Zealand's hunting history.
Developed by Doc, it involved strapping primitive radio transmitters on to goats, which were released and tracked between 1km to 10km away, depending on the terrain.
Goats tend to "mob" together and the technique enabled hunters to pinpoint a herd and use expensive helicopter resources more efficiently.
Attaching the collars involved helicopters chasing the quarry into a tussock gully and Mr Barron jumping off a helicopter skid on to the animal.
"But you got knocked around a lot, so we used net guns. But they were too clumsy."
Wakatipu biodiversity threats programme manager Mark Mawhinney said his team continued the work of Mr Barron, who retired in April, with hunting expeditions three times a year.
Three full-time staff, plus up to six seasonal contractors, used five different helicopter operators, within a $200,000 budget to shoot about 3500 goats a year.
"Technology allows us to use GPS to track ground hunters and helicopters. We're hoping GPS collars will improve over the next few years, so they will give us data on goat movements.
"All the receiver tells us is where the goat is at that time when it is in range and when we go look for it."
Mr Mawhinney said it was difficult to say how many goats were still out there, but Mr Barron said numbers were now down to "a couple of hundred" in the Dart Valley.
