He's branded them "the friendly neighbourhood serial killer", but not everyone in Gareth Morgan's neighbourhood shares his concerns about cats.
One neighbour who owns two cats laughed off the businessman's campaign to rid the country of the popular pets, saying it would never succeed.
Gina Hubbard, whose home overlooks Mr Morgan's house above Wellington's Oriental Bay, said tui and fantails were common in the area at the foot of Mt Victoria, and neither of her cats brought home birds.
"The only thing I've seen mine catch is mice."
Mr Morgan this week launched a website Cats to Go, which advises owners to keep their pets indoors 24 hours a day, fit them with a bell, and not replace them when they die because of the threat they pose to native birdlife.
Ms Hubbard, 26, dismissed the campaign, saying: "Good luck, it's never going to happen. It's like saying I don't want dogs because they pooh on the grass or something."
However, another of Mr Morgan's neighbours who would only give her first name, Alison, said Mr Morgan's campaign had made her think.
The self-confessed dog person said she had seen less birdlife in the neighbourhood in the past few years and Mr Morgan's campaign had made her wonder why.
"I think good on him because it's going to make everybody start to think. If there's a declining rate of birds I think something should be done."
Mr Morgan's arguments have drawn some support from the scientific community.
Yolanda van Heezik, a senior lecturer of zoology at the University of Otago, said Australia was among countries with regulation around cat ownership and movement, and New Zealand should consider whether to follow suit.
"I suspect that most people have never given the issue much thought, or they think that the one or two birds caught by their own cat makes no difference ... even though individual cats may catch few birds, cumulatively the total of birds killed is large."
Dr van Heezik has studied the prey caught by domestic cats in Dunedin and found cats were catching native species such as fantails and bellbirds, with fantails particularly vulnerable.
"My study identified that about one third of cats did not bring any prey home, about a half brought back prey infrequently, but that about 20 per cent were frequent hunters."
Mr Morgan's recommendations were reasonable, she said, and research showed that putting a bell on a cat reduced their catch by 50 per cent.
John Innes, a scientist in biodiversity and conservation at Landcare Research said the impact of cats on wildlife was controversial because it was site-dependent and ecologically complex.
Cats alone could not be blamed for the loss of any species in New Zealand, but they were "undoubtedly" key contributors to the decline of some birds in some places.
"For example black stilts, black-fronted terns and wrybills in braided rivers and other shorebirds trying to nest on beaches, but so potentially are hedgehogs, ferrets, stoats, four wheel drive vehicles, people walking dogs and fishermen," he said.
In New Zealand the major predator in native forests was the ship rat, which ate many more birds than cats did, he said.