DOC Claims of 1080 Success on Pirongia Possums Seriously Flawed

Diverse native wildlife on Mount Pirongia in South Waikato can flourish this summer, thanks to a successful pest control operation, says the Department of Conservation (DOC).
But the department’s claim are seriously flawed say two outdoor organisations. 
The Council of Outdoor Recreation Associations says the claims do not “statistically” add up while the Sporting Hunters Outdoor Trust said the department’s claims were simply “demonising” the possum plus using 1080 was damaging to all life including invertebrates, birds and animals.
“DoC constantly claim the possum is a predator when it’s a herbivore,” sad Tony Orman Trust spokesman.
He said Landcare Research studies had shown no presence of meat, feathers or eggs in autopsies on possums. Landcare had told DoC as far back as 1994 at a departmental “Possum Pest Workshop” that possums were not “rapacious consumers of foliage”.
Browsing of the forests was millions of years old by several moa species and vegetarian birds such as kokako and kereru (pigeon). NZ’s vegetation evolved and functioned under a strong browsing regime.
Collateral Damage
Andi Cockroft, CORANZ chairman, said DOC did not seem to understand the collateral damage 1080 did, particularly by indiscriminate aerial scattering.
“The wild celebration that they can now hear the hauntingly beautiful kokako – after it has been reintroduced. Basically it’s  kill everything then reintroduce a species with few if any competitors left after poisoning. Wonder where the Ruru (morepork) figures in this futile, damaging exercise,” he said.
As part of DOC’s ongoing nationwide Tiakina Ngā Manu programme, predator control was carried out at Pirongia Forest Park in September 2020, using aerially applied 1080 over 14,000 hectares.
The work says DoC, is part of long-term conservation efforts at the site, which is habitat for a huge range of forest birds, insects, lizards and plants including, threatened species such as pekapeka (bats), kōkako and Dactylanthus-a rare parasitic plant.
“Possum monitoring, before and after the control operation shows we’ve reduced the possums in the forest park, providing rata trees, Dactylanthus, kokakō and a multitude of other valuable New Zealand species the opportunity to thrive,” says DOC Biodiversity Ranger Cara Hansen.
Possum monitoring was undertaken by an independent contractor using leg hold traps spread throughout the forest park in the weeks after the Tiakina Ngā Manu operation was completed; 240 traps were checked over three nights and no possums were caught.
Monitoring at the same site, undertaken in January 2020, showed 5.4% of the traps had caught possums.
“This further demonstrates the value of our predator control operation and the detailed and lengthy planning and consultation we put into undertaking that work,” Cara Hansen said.
But Andi Cockroft challenged the integrity of the monitoring.
“Firstly, setting only 240 traps over that area would statistically only give us around a 7% margin for error with 95% confidence – sorry statistical chatter,” he commented.
Secondly, 240 traps with 5.4% catch are well inside a 7% margin for error. This means one could expect between 0% and 12.4% in any repeated catch. DoC then trapped after the drop and found nothing said Andi Cockroft. 
“So again assuming a 7% error rate, we could realistically expect between 0 and 7% catch rate if repeated. So there could easily be possums, even more than before, they just haven’t detected them this time. Single tests are also pretty meaningless. In essence, their “statistics” would fail 1st-year University,” he said.
Tony Orman said Landcare Research studies had indicated 1080 drops disrupted the food chain equilibrium with disastrous consequences. Major studies in 2007 revealed when 80% of rats are killed by aerial 1080, the surviving 20% quickly flourish with less food competition and mushroom into a population explosion that within four years results in 3 to 4 times original numbers. Then stoats whose main prey are rats, explode in numbers.
“All DoC has achieved in ecological mayhem with rat and stoat plagues. It’s mad, wasteful of public money and ecologically devastating,” he added.

Andi Cockroft says DoC is just seeking vote allocation money and will present “fairy tales” to get it.
”Of course encouraging an artificial rat and mustelid plague every 4 years by these regular applications of 1080 is completely self-serving to DOC’s survival as a money-go-round,” he said.

Possums are herbivores not predators

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11 Responses to DOC Claims of 1080 Success on Pirongia Possums Seriously Flawed

  1. Rex N. Gibson says:

    Clearly it is just departmental spin. You cannot claim success on the bases used. Possum numbers cannot just be given in isolation we need to know the impact on the non-target species as pointed out in the article. Expect a barrage of these articles that promote 1080 as DoC fight back against the growing disquiet in the wider community about this insidious poison,
    Rex N. Gibson

  2. Edwin Nash says:

    I cannot believe the fibs DoC spins. It’s quite incredible the research is there about rat numbers spiralling upwards after aerial 1080 drops but DoC never mentions it and continue to tip an ecosystem toxin over the public’s lands. Why too are Ministers of Conservation so blind and deaf?

  3. Alan+Rennie says:

    And no account of the trappers who trapped the area before the 1080 insecticide was dropped .

  4. Dave Rhodes says:

    The problem is ages old……

  5. Charles Henry says:

    According to Pirongia Te Aroaro O Kahu Restoration Society, Mt Pirongia has 2,280 hectares of pest control.

    If they set 240 traps in that area, that’s an average of one trap every 9.5 hectares. So their pre-poison capture rate of 5.4% (or 13 possums) is one possum per 175 hectares.

    That’s pretty dense population there!

    Now when I set my traps on my ½ acre section at home, I am more or less guaranteed to catch a possum on just about every night – may be the bait they’re using isn’t any good or there are just not that many possums around in Pirongia!

    Again, according to Pirongia Te Aroaro O Kahu Restoration Society, they have 65 robins and 44 kokako translocated – as Andi Cockroft of CORANZ says, kill everything then reintroduce species with no competition.

    But what is not seen in these statements from DOC is what was the population of stoats and rats before the drop? We all know possums are herbivorous, so present no threat. But what of other threats? – no mention!

  6. Predator Pete says:
    Sound familiar?
    If possums were predators rather than being road kill we should be seeing possums eating road kill. There are only 3 species of native birds that are strictly nectar eaters.
    A biocide/insecticide kills the birds DOC are trying to save plus the insects they feed on.
    Bureaucratic “group think”!

    ~mod supplied URL corrected

  7. Brer Possum says:

    IN the NKC Farmer dated 19-1-21 Marty Foote, Professional Trapper says trappers are cost effective and get a better result than 1080 Poison. He has been trying to get DOC to trap Mt Pirongia instead of 1080 drops for more than a year. He has historical possum monitoring info from DOC showing 1080 has not killed the numbers of Possums claimed. These findings are backed up by scientists which confirms 1080 can be expected to fail at 30% of the time. DOC national Operations Manager Hilary Aikman rejected Marty’s application to ground trap Mt Pirongia possums because she does not believe that he can achieve the results he claims for the price compared to using 1080. After 18 months of of repeated requests for a max possum density for Mt Pirongia, DOC won’t provide a target density and would only say that the pulsed control target was 3% residual catch for a 6 year pulse. When he tried to get the density number confirmed, DOC staff were instructed to cease communication by Hilary. According to Marty, DOC’s approach is defined by using prescriptive input contracts, so people can achieve results. It is more expensive than if DOC allowed contractors to submit alternative proposals. It has been many years since DOC has allowed contractors to submit output contract proposals and most of the more recent output contractors have been employed by OSPRI and regional councils on TB operations, where they are often being employed to clean up failed poison areas.
    Marty says DOC has lost much of its institutional knowledge about output contracting, with the few older DOC employees who do have the knowledge, being swamped by younger employees with no personal experience working with output contractors and whose theoretical thinking is wrongly taking the form of indisputable fact.
    From what I can gather about the comments about Marty he is an extremely good and experienced Trapper with years of experience.

  8. Stewart Hydes says:

    For more than 60 years, we’ve been ever-increasingly raining Aerial 1080 on our forests, and backcountry – with a huge increase over the past couple of decades. During this time, there has been massive decline in native species populations .. a big increase in native species either threatened or endangered.
    And not a single native species in demonstrable, widespread recovery, as a result.
    TB .. the other big lie used to continue to justify Aerial 1080 .. is long gone. We’ve been TB-free by international standards .. for years. And TB was always spread by movement of infected livestock anyway …
    There can be no doubt that Aerial 1080 has contributed significantly to the decline in Kea populations. These unique and special birds epitomise the susceptibility of native species to Aerial 1080 .. but they are just the tip of a very large iceberg.
    The utter futility of the whole Aerial 1080 industry (except to line people’s pockets) .. and the ecological devastation it wreaks .. really is beyond belief.
    It’s the world’s worst example of indiscriminate, widespread, aerially-applied, state-sponsored chemical pollution .. thousands of tonnes of a WHO Class 1A ecotoxin, across millions of hectares .. killing everything that consumes oxygen.
    Witnessing the devastation is enough to bring outdoors folk to despair .. it’s so wrong, on every level.

  9. Michael Gregg says:

    The continued rhetoric and suggestions of ‘two sides to this story’ are tiring. Surely someone needs to study all the DOC reports and conclude some more absolute findings?

    Oh wait, they did. [Below is directly quoted from the Waikanae Watch newsletter and reported elsewhere]

    Two USA scientists retired to New Zealand, Pat and Quinn Whiting- O’Keefe audited Department of Conservation scientific research and produced an 88-page monograph reviewing more than 100 scientific papers dealing with 1080. Originally from Stanford Research Institute and University of California, San Francisco in the USA with a considerable knowledge in chemistry and an expertise in statistical inference in complex systems, Pat and Quinn Whiting-O’Keefe focused on the aerial poison drops of 1080 to kill possums and rats.

    In their words:- “The results are startling and belie most of the department’s claims. First, there is no credible scientific evidence showing that any species of native bird benefits from the dropping of tonnes of 1080 into our forest ecosystems, as claimed by the department and Kevin Hackwell (Forest and Bird). There is certainly no evidence of net ecosystem benefit.”

    Surely we should be putting this debate to bed by now.

  10. Greg Kemp says:

    From a submission made to ERMA in early 2007, mention was made of the vilifaction of renouned scientist Mike Meads and how DOC were responsible for hounding him out since his views on 1080 didn’t match the corporate position.

    In August 7, 1995, “Rural News” reported “former government scientist Mike Meads predicted that continued 1080 airdrops over New Zealand forests will destroy much of the food supply of ground eating birds like the kiwi.”

    Mike Meads warned that because 1080 wipes out many leaf-consuming insects and micro-organisms, the litter fails to properly decompose and builds up at an alarming rate.

    He was quoted as saying there was already an amazing leaf build-up in some lowland forests because without the organisms, after 1080 aerial drops, the leaf litter was not decomposing. Complicating the matter was the unusually long life cycle of many forest invertebrates, e.g. cicada has a 17 year life cycle, weta two years. One air drop of 1080 can wipe out 17 generations of cicada larvae and they and wetas were important in the kiwi’s diet.

    Meads worked for DSIR from 1969-1992, transferred to Landcare Research and was made redundant after completing a year long contract study for DOC on the effects of 1080 on non-target invertebrates of the forest floor at Whitecliffs, Taranaki in 1991.

    DOC refused to publish the papers. In addition DOC reportedly put the papers to a peer review which was (predictably) critical.

    The instance highlights the science regime which exists under the way in which research has been privatised and subjected to commercial pressures. In other words the integrity of science has been undermined.

    I have spoken to scientists and they have expressed frustration at the auction system of bidding for funds. In addition working for a client on contract means that a scientist is forced to come up with conclusions compatible with the client’s policy or aim or else face the fact of getting no more contract work and suffering harassment as Mike Meads found.

    When Mike Meads’ research conclusions came up contrary to DOC’s policy, the outcome was almost predictable. His paper was subjected to a “kangaroo court” peer review and he was made redundant.

    But the Meads research at Whitecliffs had strongly, and bravely, made a point that 1080, if used, must be used carefully.

    The “Rural News” report said Meads was not against 1080 as a vector control tool if used safely such as in bait traps, where it would be specific to a given animal and then directly quoted him as saying “But widespread aerial distribution can only have serious long term effects on forests and forest life with enormous risk of destroying the ecosystem.”

    Mike Meads was no ordinary scientist. He was regarded as an authority on some of New Zealand’s rarer invertebrates, including the threatened giant wetas, published more than 100 papers in many New Zealand and overseas journals and delivered papers to international conferences in Australia, UK and USA.

    But Mike Meads wasn’t the only scientist to warn of the adverse ecological effects of 1080.

    In 1989, DSIR scientist Peter Notman (“Rural News” Oct 9, 1995)) found many insects, particularly subsoil leaf litter feeders, are highly susceptible to the systemic and contact poisoning effects of 1080.

    “Rural News” October 9, 1995, detailed the reaction following Mike Meads research as “Landcare, his new bosses, didn’t like his conclusions. His report was subjected to five different peer reviews by Landcare scientists, each recommending changes. Meads made changes that didn’t interfere with his basic conclusions but faced delay after delay as his paper was bounced around the department—-the paper’s much altered final draft was eventually sent to the Department of Conservation and they didn’t like it either. They sent it off for a sixth ‘peer review’ with an unnamed scientist in an unnamed Crown Research Institute. And they commissioned another Landcare scientist, ornithologist E B Spurr an authority on birds, but not on insects, to duplicate Meads’ project in two different forests about to be aerial poisoned.”

    Meanwhile the bureaucratic juggernaut was burying Mike Meads and his findings.

    Mike Meads was due to deliver his Whitecliffs study at a Royal Society science seminar in December, 1993. Ten days before the seminar, Meads was made redundant along with Peter Notman, who had first found 1080 affected subsoil insects. Meads was told he could deliver his paper, if he paid all his travelling and accommodation expenses which he couldn’t afford to and his paper was not delivered.

    Instead, reported “Rural News”, the seminar heard two papers by an ornithologist (birds) on 1080 airdrop effects on invertebrates. “Both papers tended to play down the adverse effects of 1080” and according to “Rural News”, Mike Meads use of pitfall traps criticised in the six peer reviews, were used in the research of Spurr’s, but in that case were not criticised!

    The case of Mike Meads underlines the lack of integrity by those responsible for the 1080, in this case DOC and some responsible for research, in this case Landcare Research.

    Note ERMA was disestablished in 2011 and its functions replaced by the EPA

    ~note from moderator: it is interesting to note that the EPA has never brought a single prosecution – data on ERMA is unknown

  11. Lewis+Hore says:

    How come if 1080 is saving endangered species it was recently reported in the media kiwi were being killed at a rate of 20 a week and would be extinct in 60 years.

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