A NEW Zealand economist has called on his fellow Kiwis to rid the island nation of all its cats.

Economist and philanthropist Gareth Morgan is calling for the eradication of pet cats and has launched a website, Cats to Go, where he urges Kiwis to make their current cat their last.

The website says: "That little ball of fluff you own is a natural born killer."

It highlights the devastating environmental impact of our furry feline friends.

"Every year cats in New Zealand destroy our native wildlife. The fact is that cats have to go if we really care about our environment."

The website features an edited image of a kitten with red eyes and devils horns, while a YouTube video includes the statement "cats are the only true sadists of the animal world".

"We don't suggest you knock your favourite furry friend on the head. We do suggest you think about the consequences on the bird population of domestic cats, and make this cat your last," the website says.

Forest and Bird advocacy manager Kevin Hackwell says Mr Morgan is raising an important issue.

"They do kill an awful lot of native species: native birds, skinks, geckos, wetas," he told AAP.

"If people want to have native birds and other native wildlife in their gardens and in their cities, then they need to be responsible in their cat ownership."

Mr Hackwell says cat owners should make sure their pet has been neutered and if it can't be kept inside, they should consider getting a bell.