A campaign to eradicate New Zealand's cats as a way of protecting native wildlife has raised the hackles of pet lovers.

Gareth Morgan, a businessman turned philanthropist, has called for New Zealanders to give puss the boot, citing research showing the average cat kills at least 13 native birds or animals each year.

He said the figure was unacceptable in a country where many bird species had already been wiped out and 37 per cent of those that remained, such as the flightless kiwi, were endangered because of introduced predators.

Mr Morgan, best known for helping to ship a stray Emperor penguin dubbed Happy Feet back to Antarctic waters after it washed up near Wellington in 2011, said cat owners should keep their pets indoors and not replace them when they died.

"Naturally, I'm not suggesting you go out and knock your furry friend on the head right now," he wrote in the Dominion Post newspaper.

"But if we are serious about conservation, then we must acknowledge that we are harbouring a natural born killer."

Mr Morgan's campaign has not gone down well in a country where a 2011 survey showed almost half of all households own a cat, one of the highest rates in the world.

Society for the Prevention of Cruelty to Animals (SPCA) executive director Bob Kerridge said Mr Morgan had no right to tell people they could not have cats in their family.

"I say to Gareth Morgan, butt out of our lives," he told television station TV3.

"Don't deprive us of the beautiful companionship that a cat can provide individually and as a family."

Even on Mr Morgan's own website, opinion was running against his campaign, with three-quarters of respondents to an online poll answering negatively to the question: "Would you make your current cat the last one you own?"

John Innes, a wildlife ecologist with government research body Landcare, said Mr Morgan's argument that cats killed birds may be too simplistic, pointing out they also kill rats, another major bird predator.

"No-one's ever actually done the numbers to see whether the number of birds that those rats would kill is bigger or less than the number that the cats kill," he said.



"I'm not saying that [cats] are good for birds, but it's not a stupid suggestion."

AFP