A Plan to Save New Zealand's Birds: Get Rid of Cats HONG KONG - A prominent New Zealand economist has set off a firestorm by suggesting that cats should eventually be eliminated from his country, claiming they are posing a dire threat to native bird species. Gareth Morgan, an economist and environmentalist, says that the cat is actually a "friendly neighborhood serial killer" when it comes to birds, and his Web site suggests that New Zealanders should gradually reduce the local feline population by having all cats neutered, and that when cats do die, their owners should not replace them. This problem, he says in his anti-cat site "Cats to Go," is that cats are gradually endangering New Zealand's rich avian diversity, having helped kill off nine native species while endangering another 33. New Zealanders, it turns out, have an affinity for what Mr. Morgan calls "that little ball of fluff" that he maintains "is actually a natural-born killer." The New Zealand Pet Food Manufacturers Association, which of course has a stake in such statistics, reports that 48 percent of New Zealand's households have cats, "making it the highest cat ownership rate in the world." The issue of the feline threat to birds has been documented before. A study on the deaths of baby gray catbirds in the Washington suburbs found that "80 percent of the birds were killed by predators, and cats were responsible for 47 percent of those deaths." One issue is that with their domestication, cats have few natural predators. Still, Mr. Morgan's campaign calling for the eventual elimination of cats from New Zealand has drawn an angry response from cat lovers and some animal groups. "A cat-free anywhere is not a good area," said Bob Kerridge, executive director of the Auckland Society for the Prevention of Cruelty to Animals, who added that we should "leave it to nature to take care of things."