Gareth Morgan best to take more moderate approach.

Extreme views rarely garner respect. Usually, they prompt a tumble in the stocks of the proclaimers of those opinions and a spurning of whatever has aroused their ire. So it will be with economist Gareth Morgan's campaign to eradicate domestic cats. His means of achieving that aim, including keeping pets indoors 24 hours a day and not replacing them when they die, is simply too radical to strike a chord in the 1.6 million households that own cats. Absent from his campaign is any acknowledgment of the emotional ties that bind those households to their pets.

Dr Morgan is not, in fact, saying anything particularly new. The carnage wrought by cats and other alien hunters, such as dogs, possums, rats, weasels and stoats, on this country's totally unprepared native birdlife is well documented. It is said that a single lightkeeper's cat accounted for an entire species of wren on Stephens Island in the Marlborough Sounds. Dr Morgan is merely stating a fact when he says the effectiveness of cats as hunters continues to be a threat to our native birds. A recent University of Georgia study of cats' predatory skills underlined his point. It found that about a third of pet cats are active killers of a wide range of wild animals.

Dr Morgan's conservation prescription is, however, as problematic as it is extreme. He seems not to have thought through the consequences of keeping cats inside all the time. Fatter and less healthy pets would surely result. Nor has he paid sufficient attention to the way that cats keep the rodent population down, especially during nocturnal outings.

Indeed, his proposal may have a malign outcome. Landcare Research wildlife ecologist John Innes has noted there is "substantial uncertainty" over whether taking cats out of the equation would be better for birdlife because of their part in keeping rats and other introduced predators at bay. "You can't say that cats are bad because they kill birds," he says. "It's simply not that simple."


Effectively, Mr Innes is suggesting the ecosystem is not as straightforward as Dr Morgan contends. This, however, has not stopped others of his view recommending similar radical responses. Many cities of the United States and at least one state have considered restraint laws. Sometimes, this has included requiring cats to be on leashes. Such efforts have proved hopelessly ineffectual, not least because of the difficulty of policing a huge number of domestic cats.

Dr Morgan's proposed solution will, inevitably, also founder. But that is not to say there is no merit in his view that we should recognise the economic benefit, and the ecological dividend, in retaining our huge range of bird species. It is, as he suggests, not only unique but a part of the country's clean and green image.

But he would have far more chance of achieving this aim with more moderate proposals that resonate with cat owners. Such an approach might suggest people should be more aware of cats' hunting ability and take steps to acknowledge this. These would include neutering and chipping them, feeding them properly, and attaching a bell, so birds have some warning of a cat's approach. In effect, cat owners would take on responsibilities more in line with those attached to dog ownership.

Dr Morgan has suggested a public backlash will not put him off pursuing his agenda. "I've got another angle on all this once I see how round one goes," he says. Hopefully, that angle will pay considerably more attention to cat owners' sensitivities. It will need to if he wants to gain any traction for his conservation concerns.