Gareth Morgan's website, Cats to Go, accuses domestic cats of posing a danger to native wildlife, particularly birds, and alleges felines were partially responsible for the extinctions of nine bird species in New Zealand, The New Zealand Herald reported Tuesday.
"That little ball of fluff you own is a natural-born killer," a video on the website says. "Cats are the only true sadists of the animal world."
The website calls on New Zealanders to stop buying new cats and not to replace their old pets when they die.
Morgan could not be reached for comment, the Herald said.
Bob Kerridge, chief executive officer of the Society for the Prevention of Cruelty to Animals, described Morgan's views as "a bit radical, over the top and completely wrong."
He said the arguments on Morgan's website are based on faulty research.
"People blindly say, 'Yes, it's cats that kill all the birds,'" Kerridge said. "Gareth Morgan is way out of line because very few native birds fall at the hand of cats, domestic cats."