A retaliation site set up in response to Gareth Morgan's controversial website advocating people get rid of their cats  depicts and image of a cat dragging the shot carcass of a fox with Morgan's head superimposed on to it.

The philanthropic economist has called for people to hold off on replacing their cats once they die, but the push to protect New Zealand's native birds has not gone down well with many moggie-lovers.

Morgan's site catstogo.org.nz has caused outrage among cat lovers, but applause among many scientists and conservationists.

But another site- cats2go.co.nz - appears to have been set up group Catslovenz.

The group have left their email address on the site, and a cryptic message saying "New website coming soon".

Morgan's site says cats contribute to the extinction of nine native bird species and impacted on 33 endangered native bird species.

It went on to say that killing cats is not necessary but is an option.

"We appreciate the fact that you have an emotional connection with your pet and that pet ownership is a rewarding experience," the site had said.

"But there's a real problem with cats - they kill for pleasure, and most of that killing is out of your sight so probably out of your mind.

"If you think New Zealand's native species are precious and should be fostered then it's important you be a responsible cat owner."

The campaign has been the cause of much debate among scientists and cat-owners, with the latter claiming their beloved pets were not "natural born killers".

Prime Minister John Key was among critics of the site, saying the idea was "barking mad".

But some scientists have supported Morgan's solution saying cats were a big part of the problem.

Otago University senior lecturer Dr Yolanda van Heezik said the proposal was reasonable and would prove effective.

"Consider using a collar with a bell: our research has shown they reduced catch by 50 per cent," van Heezik said.

"Consider keeping your cat inside at all times. This ruling is in effect already in some parts of Australia. And consider not replacing your cat when it eventually dies."

Edit: The original version of this story incorrectly said Gareth Morgan's website had been hacked.

- © Fairfax NZ News