By John Kerr 26/07/2016

The New Zealand Government has just unveiled ‘the world’s most ambitious conservation project’: eliminating introduced predators such as rats, possums and stoats by 2050. But is it a realistic goal?

The Prime Minister John Key announced the target yesterday , starting off with with a new $28 million joint venture, Predator Free New Zealand Limited, which will sponsor community partnerships and pest eradication efforts around the country.

“This is the most ambitious conservation project attempted anywhere in the world, but we believe if we all work together as a country we can achieve it,” said Key.

From the Beehive:

“New Zealand is a world leader in conservation technology and research,” Science and Innovation Minister Steven Joyce says. “The Biological Heritage Challenge has an established network of scientists who are ready and willing to take on the Predator Free Challenge. For the first time technology is starting to make feasible what previously seemed like an unattainable dream.”

Predator Free New Zealand Limited will have a board of directors made up of government, private sector, and scientific players. The board’s job will be to work on each regional project with iwi and community conservation groups and attract $2 of private sector and local government funding for every $1 of government funding.

Four goals for 2025 have been set for the project:

-An additional 1 million hectares of land where pests have been suppressed or removed through Predator Free New Zealand partnerships
-Development of a scientific breakthrough capable of removing at least one small mammalian predator from New Zealand entirely
-Demonstrate areas of more than 20,000 hectares can be predator free without the use of fences
-Complete removal of all introduced predators from offshore island nature reserves

The bold plan is already making headlines overseas, with the BBC, Guardian and Shanghai Daily covering the announcement.

‘A reasonable goal’

The response from New Zealand conservation scientists has been one of cautious optimism. Here is a snapshot of the expert reaction collected by the Science Media Centre:

Dr James Russell, conservation biologist, University of Auckland:

“We’ve been part-way there for some time. Already nearly half our offshore islands are free of introduced mammalian predators, but these are only the smaller islands (10% of total area). It has taken us 50 years to arrive here, so 2050 seems a reasonable goal and matches our current scaling laws for eradication size.”

Doug Armstrong, Professor of Conservation Biology, Massey University:

“The goals seem good, including the general goal of eradicating rats, stoats and possums by 2050, but it is impossible to say whether this general goal is realistic at this stage.  It is clearly feasible to eradicate these species from Stewart Island if there was sufficient public support to do this.”

Dr Marie Brown, Senior Policy Analyst, Environmental Defence Society:

“This goal is pretty aspirational of course – but vision and audacity is a good thing in conservation. It engages people and makes the impossible possible. Much of what we achieved in conservation in the latter half of the twentieth century would have been inconceivable in the first.”

Dr Wayne Linklater, co-director Centre for Biodiversity and Restoration Ecology, Victoria University Wellington:

“There is evidence … that the political and logistical approach – marrying government, business and philanthropy – might be timely and powerful enough to achieve it.”



The price of predator free

Commenting on the total cost of reaching the Predator Free 2050 target, Dr Russell said:

“Without a clear idea of what the final knowledge advances are which will help us achieve Predator Free New Zealand, its hard to make a reliable costing, but certainly it will require a prolonged investment staged across multiple governments, but with the right economic model, the annual costs could be only a fraction of a percent of GDP.”

An analysis by Dr Russell and colleagues, published in the journal Bioscience earlier this year, gave a rough estimate of $9 billion for scaling up predator eradication efforts to a national level over 50 years, acknowledging the difficulties in costing out the scenario.


Feral cats will be targets under the new predator-free initiative. Flickr / Alex D
Feral cats will be targets under the new initiative. Flickr / Alex D

What about cats?

The definition of predator in the context of the 2050 goal does have a little wriggle room when it comes to domestic pets. When asked about the status of cats in the ambitious plan, Prime Minster John Key told the New Zealand Herald:

“Moonbeam [the Key family cat] is safe as a house. If you’re asking about feral cats on the DoC estate, their time is limited.

“They will be targeted. But in terms of the domestic moggie, then they’ll still have plenty of years in front of the fire.”

Featured image: Flickr / G =]

0 Responses to “Predator free NZ: Can we do it?”

  • Finally!. An aspirational goal that New Zealand scientists and public can get behind. The advances in drones, robots, GPS and other technologies can make this achievable. I hope that the money is carefully targeted at science and technology needed to further this objective, such as improved chemical lures and poisons, better traps, GPS, use of drones/robots, etc. I don’t want any of the money going to the same poorly-focussed university projects that haven’t delivered useful responses over the last decades.

  • Does anyone know what the potential scenarios are for the stated goal of a scientific breakthrough by 2025 to eliminate one mammalian predator? What are we talking here – mass sterilisation? A genetic solution? Any ideas?

    • Sterilisation I think, has been more successful with insect pests where with a short generation cycle, you can quickly reduce population. Vespid wasps are a nasty predator, but not mammalian so I don’t know that this will be work.

      I suspect the most plausible scenario is some combination of attractant/bait/poison that is very targeted to a particular mammal. Even if we have some genetically engineered disease that say, generates sterility (or kills mammal) , then yuo’re still likely to need bait & poison to finish the job.

  • Hmmm, a $9 billion estimated cost over 50 years started with initial funding of $28 million! Me thinks that this is all just the creation of a new bureaucracy, with long-term funding benefits for those involved. Note that the Russell et al. article (doi: 10.1093/biosci/biv012) says “The proposal includes invasive predator eradication from the two largest offshore islands, mammal-free mainland peninsulas, very large ecosanctuaries, plus thousands of small projects that will together merge eradication and control concepts on landscape scales”. This sounds to me like something less than national eradication everywhere, but rather just an unspecified number of eradication projects, as many as funding allows, keeping people busy …

  • I’ve always believed it can be done with enough resources and money. I never thought I’d see something like this from a Government that has been cutting DOC funding and changing job description of degree holding employees from Ranger to tourists’ guide and toilet cleaner, for example.
    Is it a cynical attempt to lure environmentally conscience voters away from a Labour-Green alliance?
    Every single time an opposition Party floats a grand goal the National Party say (over and over) How are they going to pay for it? (Instill doubt) Will they raise taxes? (Instill fear) Then generally rubbish the whole idea.
    I absolutely Love the idea of elimination those pests but is National serious? And will Labour steal the idea? Snap!

  • Is a literal Predator free NZ optimal? Given there are costs to to such a program I can’t help but think the optimal number of predators is greater than zero. One would like to see better estimates of the costs of such a plan and details of what the criteria are for evaluation of the success/fail of the plan.

  • @Paul I think you are right Paul – when we approach conservation scientists for reaction to the announcement I was surprised that almost all of them hadn’t heard this was in the works and those who had heard, only had a vague idea of what was coming. So some of the key people who could have input into the evidence base underpinning this initiative, clearly haven’t,

  • Which suggests that the “evidence base” may be lacking, possibly because this is just an overhyped funding begging bowl …

  • One possible reason that the apporoached conservation biology experts didn’t know much about the programme is that they didn’t interact with many of the chariable trusts set up with specific local conservation aims. Sir Rob Fenwick was one of the main drivers in making Mototapu and Rangitoto islands predator-free. All around NZ are diverse trusts and groups working to make areas and islands predator-free, probably with minimal interaction with academics. We have come along way in the last two decades, but now need to introduce novel technologies and science into the war.

    It is inspirational that various islands around NZ are now predator-free, as well as some parts of the larger islands. That’s why I believe the objective is possible. The cost will be large, but the ongoing benefit to our environment can also be very great. Obviously the term describes introduced predators that have become pervasive due to unchecked breeding, not native predators such as Morepork and NZ Falcon.

    The cost will increase with time, but if the initial money goes to researchers that can develop superior toxins and technologies, the chance of success increases. If the initial $28 million available for the first four years is doubled every four years, $12 billion would have been spent by 2050.

    All introduced major predators would have to be exterminated. Not sure what Paul means about optimal number, but it has to be zero for the all the current introduced major predator species because of their breeding rates. I don’t follow economics, but as far as I’m aware for human predators, zero is the only acceptable number of free-roaming paedophiles predating children in NZ. If there’s an optimal number, I’d like to know how that’s assessed.

  • “All introduced major predators would have to be exterminated. Not sure what Paul means about optimal number, but it has to be zero for the all the current introduced major predator species because of their breeding rates.”

    He simply means that the marginal benefits equals marginal costs of removing the marginal predator. It may be that MB=MC at zero, but this is something that would have to be shown, otherwise we will waste a lot of resources removing predators when the benefit of doing so are less than the costs of doing so. Related to this is the point that we need the criteria for evaluation of the success/fail of the plan. How do we know when to stop? How are we to know if the plan has failed? Or succeeded? Given the amount of money to be spent we do need to know its being well spent.

  • We should learn from history. The arrival to mustelids in NZ devastated bird populations so much that by 1891 the public and government were so concerned that Resolution Island was gazetted as a reserve. Despite Richard Henry’s best efforts, stoats arrived on the island around 1900 and annihilated animal and insect populations. The list of species exterminated on mainland NZ due to introduced predation is long and growing. The cost of trying to recover relict species ( eg kakapo, black robin ) is huge. Even if we make NZ predator-free, there will always have to be eternal vigilance to stop rapacious predators ( other than humans, who we apparently can’t poison or trap ) from arriving and restarting the cycle.

    Just as I’m opposed to pouring some of the new money into ongoing academic programmes that have failed to provide useful problem identification and solutions to predation, so I’m opposed to trying to assess costs before we have even started to assess options. It’s clear from history and some recent sanctuaries that zero numbers of breeding rapacious predators is the only acceptable number, otherwise the only “marginal” factor will be time to species extinction.

    If the destination is species survival, there will be plenty of time during the journey to consider costs. For example, if we kill all predators of one gender, the predator population should decrease to zero. Until we develop options to exterminate predators, costs will remain unknown, however we know the current techniques will not be viable for larger islands. As noted above, costs will increase with time, so start now, and review regularly. One estimate of the total cost would require an increase of around 18%/year from the initial $7 million annual cost.

  • @Stephen Thorpe

    Just a random comment…

    It’s refreshing to see a comment section where people don’t even bother to respond to stale trolls like yourself.

    carry on.

  • @Ichthyic

    You mean where people are too scared to grapple with the real issues! I was just saying things as they are, you are “trolling” me! You are nuts if you think that the entire country will be predator free by 2050!

  • Will need to do something at the same time with deer, tahr, chamois, pigs and hares. The flora is suffering badly. These seem to have dropped out of the debate.

  • Good point! I wonder how much it will cost to make NZ herbivore free!

  • And might not these herbivores (at least hares/rabbits) thrive in the absence of predators?