The goal of making New Zealand predator-free by 2050 has always seemed extraordinarily optimistic.
In the early days of its Cultural Revolution, China reportedly exterminated crop-raiding sparrows by the low-tech method of countless millions of people making so much noise that the birds were afraid to perch, and either died of exhaustion or fell to the ground, where they were dispatched.
That technique is unlikely to work here.
For a start, getting everyone to hunt down every last possum, rat, mouse, mustelid and feral cat in the land would require billions of dollars in government grants, given our growing national distaste for making any sort of effort without remuneration, but the real problem is that there just aren't enough of us. And the predators that are driving some native species to extinction aren't always that easy to get to.
That's where 1080 comes in. And that, for conservationists, is the second front in what already appears to be an unwinnable war.
'Efforts are being made to find alternatives to 1080, but there are no signs of significant progress there. And be assured, when there is, some people will oppose them, whether they come in the form of new toxins or, as seems more likely, fiddling with the predators' DNA.'
Saturday's protests offered all the evidence needed that 1080, particularly applied from the air, will never be accepted by many New Zealanders.
Some regard it as inhumane, and no one seriously argues that 1080 poisoning is not a horrible way for any animal to die, but the more serious issue is the refusal of critics to be persuaded that it does not do more harm than good.
This newspaper has been running 1080 stories for decades, and the opponents have never wavered. They claimed, and some still do, that forests that have been treated with the poison become lifeless deserts, birds and insects wiped out along with the pests that prey upon them. A pyrrhic victory if ever there was one.
Aerially-applied 1080 inevitably finds its way into water, threatening not only every species that lives in those forests, but eventually people. Assertions by those who have much greater scientific knowledge than most of us that neither argument is valid have always fallen on deaf ears, and still do.
The most recent defence of 1080 comes from Dr Belinda Cridge, from Otago University's Department of Pharmacology and Toxicology, who does not believe that all who oppose the use of 1080 are well informed. Realistically she isn't counting on those ill-informed critics to fall silent any time soon.
Dr Cridge says birds and reptiles seem to have a degree of tolerance to 1080. Not so mammals, which explains why the toxin is used here, a country that has only two native mammals, neither of which will ever come into contact with it as it is currently used, whereas many other countries have native mammals that would be exterminated, along with targeted pests.
And no effort is seemingly spared to ensure that 1080 applied from the air lands only where it is supposed to go. The ability to achieve a high degree of accuracy is unquestioned, although there have been claims over the years — not so much in recent times — that it has been found on farm land adjoining bush.
Pigs and deer, regarded by some in some areas as pests themselves, highly valued by others as game, undoubtedly fall victim to it, a degree of collateral damage that some accept, while others do not. It's been a while since anyone claimed to have lost a dog to 1080, but, properly controlled, they should not be at risk.
Dr Cridge also says scientific understanding is that the original 1080 compound breaks down quickly in the environment, including water. She doesn't say it is impossible that it will accumulate in waterways and cause down-stream poisonings, but suggests that it is unlikely.
Certainly claims that the stuff is getting into waterways and killing not only the inhabitants of those streams and rivers but endangering humans who will eventually drink the water have never been proved.
This newspaper is not aware of a single solitary instance of human 1080 poisoning. Nor is it aware of any incontrovertible evidence that it kills birds, despite offers, years ago, to pay for the expert examination of any dead bird to establish whether it succumbed to the poison.
So who do we believe? Those who say 1080 is highly effective at reducing pest populations, or those who say it kills everything, including the species it is supposed to be saving? Given the evidence that we have at this point, one has to wonder if those who wish to ban 1080 are really interested in proving that their opposition is well-founded, or whether they prefer to remain passionate but ill-informed.
Critics also claim, of course, that there are alternatives to 1080, primarily trapping. That is no doubt true in some instances, and a lot of people are putting a lot of unpaid effort into doing just that.
But the sad fact is that much of New Zealand's bush provides an unassailable fortress for the predators that are destroying it. The only way of controlling those populations, let alone exterminating them, is by poison applied from the air.
If predators are allowed to remain in inaccessible areas, the native flora and fauna that sustain them will cease to exist, and the need to control them where they can be trapped will continue forever. Far from becoming predator-free, New Zealand will remain a battle ground until the end of time, or until there are no native species to protect.
Efforts are being made to find alternatives to 1080, but there are no signs of significant progress there. And be assured, when there is, some people will oppose them, whether they come in the form of new toxins or, as seems more likely, fiddling with the predators' DNA. Genetic modification, whether it be aimed at increasing the production of food or wiping out entire species, will always be anathema to many people in this country.
Conservationists will be swapping one battle for another.
Meanwhile the damage done by predators continues. Forest & Bird advocate Dean Baigent-Mercer has long been ringing the alarm bell over what he says is the descent of the 11,500ha Russell State Forest into a state of collapse. He doesn't regard 1080 as an ideal solution, but sees no alternative. Nor, quite frankly, does anyone else.
Trapping and fencing can be effective at protecting native birds, to the point where some species are successfully being reintroduced in areas where they had been driven to extinction.
But trapping will never be the total answer, unless we are prepared to sacrifice great swathes of forest habitat, and content ourselves with providing fenced and trapped sanctuaries for species that everyone, whatever side of the argument they are on, wants to see saved.
Given the sentiments expressed on Saturday, the yawning chasm between defenders and opponents of aerial 1080 treatment remains as wide as ever. Protesters in Kerikeri, and elsewhere, claimed that 1080 is destroying "our nation". There were calls to stop poisoning paradise/"our future," and assertions that 1080 kills "everything". Oh dear.
One placard simply stated, "I'm lost." No argument there.