Armed with his trusty sidekick Bongo Fury a Wanaka man is hunting born killers hiding in a land where they do not belong.
Wanaka pest controller Billy Barton believes there are millions of feral cats in the wild, "living just where you don't think they are".
Barton, 62, would know.
At last count he had 18 hunting dogs, including the only cat scent trained dogs south of Twizel.
Last year he caught a 6.2kg cat beside the Matukituki river and 5.5kg feral cat the week before, while trapping for the conservation group Forest and Bird.
"I think the cat is an amazing animal. It is a born killer, it knows what it is doing, and to sit and watch them is brilliant.
"But they are not supposed to be here [in New Zealand], and what people don't realise is the damage they are doing to our wildlife, particularly birds.
"You have a nice kitty, you get it de-sexed and put it back in the wild and it just keeps on killing."
Barton and his partner Mary Hunt operate Phoenix SPB Ltd and manage 500 local predator traps from Roys Peninsula to Queensberry working for the Department of Conservation and a range of private clients to control predators.
He is also the only South Island white German shepherd breeder.
Welsh-born Barton bought his first white German shepherd when he was 21 and after dog training, represented his country for three consecutive years in field trials for rabbiting.
When he emigrated to Dunedin with his ex-partner in 2008 to work as a welder and engineer he brought his white German shepherd and white German shepherd greyhound cross with him.
Since then he has continued to train more white German shepherds and other breeds to hunt feral cats, rabbits, hares, stoats, ferrets, possums and rats.
During the years he spent eradicating and trapping pests on Macquarie Island, between 2013 and 2015, he started to get inquiries about removing pests from farms in Central Otago and the Lakes District.
Five years ago he "house sat" for Hunt at her Hawea Flat property and never moved out.
"I used to use eight to 10 dogs back then but I have gone up in number because it cost me $18,000 in vet fees for the first year.
"With more dogs I don't have as many vet bills because you can rotate them."
A Frank Zappa fan since he was 17 years old, Barton has named every dog, except one, as a tribute to the American singer-songwriter and rock guitarist.
"Bongo Fury, 3, is a typical spaniel in that it has mothballs between the ears, but he has been locating cat scents since he was six months old.
"Suzy Creamcheese, 6, will also catch feral cats but she is not registered with DoC, so I can only take her hunting on private land."
Barton said everything he caught was utilised.
"We freeze possums, rabbits, rats, ferrets, mustelids, and the cats. The rabbits get fed back to the dogs and rabbits' guts go to the chickens. They love it."
As well as chickens, Barton has alpaca and sheep (for aversion training), and five ferrets to seek out the rabbits.
He also makes gland oil for trapping from wild ferrets.
"I have seen evidence that cats, ferrets and stoats and possums all come in to investigate the scent."
Barton said he was starting to expand into wallaby detection and hunting and planned to build up the dog obedience and cat hunting training side of his business.
"There are not enough dogs in this region being utilised to hunt feral cats.
"We had a friend here two weeks ago and we spent the weekend dragging dead cats around and putting cat poo out there and training the dog but she was from Christchurch.
"Cats are everywhere. There are more cats out there than anyone knows about."
His work is held in high regard by fellow conservationists.
Central Otago Lakes Forest and Bird committee member Andrew Penniket said the organisation was fortunate to have Barton in the district.
"He has a wealth of experience pursuing feral cats at Macraes Flat in support of the giant skink sanctuary and when he suggested Forest and Bird undertake feral cat control in the Wanaka area we jumped at the chance to use his skills and knowledge."
Barton's cat-catching dog, combined with other predator control programmes in the area, had resulted in the removal of over 100 cats and many more hedgehogs in the past 18 months, Penniket said.
Last weekend, Barton, Hunt, Bongo the feral cat hunting dog and a ferret attended the Wanaka A&P Show, where they represented the conservation group Phoenix Wildlife Enhancement in the "Our Place" sustainability tent.