Posts Tagged ecology

Annihilate, really? – show me the evidence - Wayne Linklater Dec 18

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The nation missed an important opportunity at Raglan. If cats have been removed from the Raglan community then, had we the time beforehand to prepare, we could have tested whether cats were a beneficial urban predator, as claimed here and here.

Cats on evidence. Evidence on cats... adn their relationship with other wildlife in our neighbourhoods.

Cats on evidence. Evidence on cats… and their relationship with other wildlife in our neighbourhoods.

We could have measured the movements and survival of other native and exotic wildlife, like birds, reptiles, and rodents, in the area before and after cats were removed–called our scientific treatment site.

Importantly, we would also have compared the changes, if any, with a similar community where cats have not been removed–called our scientific control site.

Unfortunately, the scientific study has not been done or the measurements made. Nevertheless, this has not stopped some from using the Raglan experience as if it were evidence for cats as a beneficial urban predator. Forgive me for disagreeing. Last time I looked ecology was a science.

We need better evidence–scientific evidence. Current information that is paraded as evidence, like the Raglan experience and Dr. Flux’s cat, is inadequate for deciding government policy or wildlife management, although it is being used as if it is reliable information.

In the absence of a scientific comparison of wildlife before and after cat removal and comparison with a control site, it is premature to conclude that the removal of cats has been detrimental to native wildlife in the Raglan area.

I too think it possible for domestic cats to be a predator that is beneficial to native wildlife. However, I quickly add two important caveats which impose very large uncertainties around the usefulness of the idea:


The role of cats as predators, good or bad for native wildlife, is context dependent and we do not know what those contexts are or how commonly they occur. The killing of native wildlife that rats do is a reason for killing rats, not keeping cats (photo source:

1. It depends… and we do not know when

It is certain that cats will not be beneficial at all times and in all places because what cats kill, native or exotic, is context-dependent.  It depends on the characteristics of the cats, and the cats’ owners, the relative availability of exotic and native prey… and much more besides.

Thus, we should not assume that cats are always and everywhere good. Unfortunately, until the ecological science is done–because it has not yet been done–we do not know under what circumstances cats are beneficial and how common those circumstances are.

2. It is a reason for killing rats, not keeping cats

The benefit of having cats is unlikely to be as great as the benefit of removing all exotic predators of native wildlife–cats and rats.

Thus, the presence of rats killing wildlife is not a reason for having cats, it is a reason for killing rats! We would not need cats to kill rats if we got on top of the rat problem in New Zealand’s towns and cities.

Would the loss of cats in Raglan, assuming the reports are accurate, have been a problem if the community had themselves also been controlling rats?

We should do the experiment

To improve the evidence, and address the uncertainties that surround the idea of cats as beneficial urban predators, we need a community, like that in Raglan, to take part in an experiment, like the one I have outlined above or here and here. They would keep their cats indoors for a year and we would compare the changes in wildlife abundance and movements in their neighbourhoods with those of another community where cats are free to roam.

Until such time as the evidence is improved in this way, we need to implement measures which control ALL exotic predators of our native wildlife, at the same time.

Science, evidence, policy and good government - Wayne Linklater Feb 07

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Since beginning Polit-ecol Science a small number of colleagues have queried me on why I would write a blog that might be political and, to some, contentious. Some have even gone so far as to suggest that they would not do such a thing because it might impact on their chances of career advancement and success at external research funding. Frankly, the implication that parts of our science community might cower from debate and critique on issues that they could inform and that are important to others in our nation’s communities is alarming.

Policy on the environment, informed by ecological science, divides New Zealand’s parliament.

Governments, even in relatively transparent democracies have a Jekyll and Hyde relationship with science and scientists. One cannot claim the mantle of improving the quality and quantity of peoples’ lives in the modern world without co-opting science. It can contribute to political credibility to also periodically ‘roll-out’ your local neighbourhood scientist for public display – might be good for the scientist’s career advancement too. Science and scientists, if they are doing their job however, will also periodically challenge government – science, you see, is fundamentally blind to authority, even if some scientists are not.

We see this tension between science and government in the on-going debate about the quality of New Zealand’s environment and especially freshwater and fisheries. Challenges to government policy on freshwater management by individual scientists, even when the New Zealand Association of Scientists or Parliamentary Commissioner for the Environment have delivered the same message, are disputed by representatives and met with inaction. The current government appears hell-bent on under-representing or even ignoring its nation’s scientific evidence when making and applying freshwater policy.

Beliefs about our environment and society motivate and structure government policy. Scientists reduce beliefs down to their simplest tenants and phrase them as hypotheses. The belief that New Zealand’s freshwaters are in good shape can be phrased, for example, as hypotheses about the bacteria in the water or its clarity. Scientists test these hypotheses by mesuring these things. The outcomes are viewed as evidence supporting or not supporting a belief.

In science if the evidence contradicts our belief we change our belief. But this iterative process is not confined to science. Societies which allow belief to be challenged and changed by evidence are more innovative, adaptive and successful societies. Government does not represent or serve its community when it protects its beliefs from evidence.

How should we view government when it pursues policy contrary to scientific evidence, not because they have better evidence or concerns about the quality or quantity of the evidence, but because the evidence does not support their belief? We should view them as sport – professional sport for scientists.

In the Centre for Biodiversity & Restoration Ecology at Victoria University we conduct research in ecological science to inform biodiversity management and policy. I use this blog and social media to engage with people and policy that might be informed by ecological science. Ultimately, the tax payer is my boss – this is where my salary comes from. I am the people’s employee – making the science I do work for ‘the people’. Sometimes that will require that I debate and critique policy. Its my job.

Ecology by the people, biodiversity for the people.


Whipping the poor to garden – an ecological injustice - Wayne Linklater Jan 06

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Weekly newspaper columnists most often opine on people and society. Michael Laws, in his weekly Sunday Star Times column, has a particular trenchant for admonishing people with fewer resources than himself.

This Sunday, Laws advocated gardening to the poor in “Want to eat well? Simply grow your own food” (Sunday Star Times January 6th). Seldom do weekly columnists tread into ecological territory and, being an amateur but enthusiastic gardener myself, I read with interest.

It is not the first time the poor have been chastised for not gardening. Every so often a politician or self-righteous ‘green-thumb’ will also imbibe in this ecological solution to being impoverished. But is the criticism for not gardening fair, and is gardening a viable solution to being poor?

Gardening is an ecological problem made more challenging by its interaction with human behaviour and economics. Mr Law’s central tenants are that gardening is easy and that it results in a net economic gain to the household. He is dreaming.

The Fertile Cresent – the largest area on the planet with both rich alluvial soils and a Mediterreanean climate – ideal conditions for gardening.

Gardening was a late advance in human societies because it is difficult and constrained by opportunity – the fortuitous coincidence of multiple favourable circumstances at once. Growing plants for food occurred first along the Euphrates and Tigris Rivers and eastern coast of the Mediterranean Sea called, appropriately, the Fertile Crescent. The Fertile Cresent was the largest area on the planet with the coincidence of rich alluvial soils and a climate of mild, wet winters and long summers [1]. It is much harder and more costly to garden in most other places on the planet.

The first plants domesticated – wheat, barley and peas – weren’t cropped until just over 10,000 years ago, although our species has been smart enough for gardening for a lot longer than that. We domesticated animals earlier – training wolves to dogs over 13,000 years ago in western Russia and central Europe – and have harnessed fire, made tools, and communicated with language for much, much longer still [2].

Gardening also developed very slowly. Hunter-gatherer societies did not become agriculturalists overnight. They made a gradual transformation to sedentary communities that grew their food because attaining the experience and knowledge to garden well took several millennia. Gardening is not an easy thing to do – even for brainiacs.

My daughter picking raspberries under the cabbage tree – nothing else would grow there.

Although our society has solved many of the problems which faced the first gardeners, several of the original challenges remain. A coincidence of five conditions of our ecology must still occur for gardening to be easy and economically viable in the modern world (and while I list these challenges let me boast pictorially about my ‘world famous to my daughter’ zucchinis, raspberries and beans – illustrated – many more failures not illustrated). You must:

1. have a site to garden and certain tenure and security of your site,

I had wonderful zucchinis last year. Looks like a good crop this year too. My first year’s crop failed – seeds rotted in the ground.

2. start-up resources (funds, equipment, materials, time) available to invest and sufficient to succeed,

3. have soil and micro-climate at the site suitable for growth,

4. be in a place that is unlikely to suffer extreme ecological events (weather or pests) capable of destroying your crop, and

Beans, glorious beans. Broad ones finishing, and Scarlet Runners just beginning. Broad beans were my first success – robust to clay soils. Scarlet runners are perrenial lovelys, but my first season of these failed.

5. already be garden-wise.

If you invest in a garden but any of these conditions is not met, and a net economic return is your measure of success because you are poor, then you will fail and become poorer still. This is why those that garden well are garden proud. Gardening well is a magnificent achievement of socio-ecological intuition and science.

Is Michael Laws naïve? To some extent. But I also suspect him of giving the poor another hiding – he is a feral columnist. This time he has chosen to thrash them with an ecological stick – a false solution and he is wrong to do so. In future posts I will embellish on these five conditions to explain why our ecology makes gardening for food largely a luxury of the middle classes.



1 Diamond, J. (1999) Guns, Germs, and Steel. W. W. Norton & Company, Inc.

2 Clutton-Brock, J. (2012) Animals as Domesticates. Michigan State University Press.

Conservation, Zoos and Elephant - Wayne Linklater Dec 11

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Elephant in Hluhluwe-iMfolozi Game Reserve, South Africa. Photo credit: Chris Kelly.

Frighteningly, resurgent ivory demand threatens elephant with extinction over large areas of their range. It is a world-war for wildlife on a massive scale. Governments, conservation agencies and private landowners are mobilised across Africa and Asia spending enormous amounts of money to protect elephant. I hope they win the war so that our children can live in a world with big, magnificent animals.

Meanwhile, in New Zealand…

Auckland Zoo is hoping to import two elephants at a cost of about $3.2 million. Franklin Zoo is trying to raise $1.45 million to send an ex-circus elephant which recently killed its keeper to a sanctuary in the USA.

Hamilton’s Gully Restoration Program to bring wildlife back into the city cost just $65,000 but its budget was cut by $20,000 earlier this year, although only 1.6% of Hamilton’s ecological district remains in native vegetation.

Zealandia, New Zealand’s first fenced mainland biodiversity sanctuary, needs just $700,000 a year to continue to protect and advance the biodiversity gains of Wellington City, but has been under severe budgetary scrutiny.YouTube Preview Image

Ironically, Wellington and Hamilton City’s ecological restoration projects cost less each year than sending Hamilton’s single elephant to the USA. The $4.65 million to import two elephant and export another would support the annual operating costs of six Zealandias and 67 large-scale biodiversity restoration projects by communities, like Hamilton’s Gully Restoration.

Imagine it – a mainland wildlife sanctuary and city-wide ecological restoration project in every major city and large town in New Zealand bringing the forests and birds back to our cities and our grandchildren.

At least 2788 New Zealand species are threatened with extinction. New Zealand has one of the world’s worst records of habitat loss and species extinction. We could reverse that trend by protecting and restoring habitat, but we are limited by a lack of funds.

The cost of importing and exporting three elephant compared with expenditure by community groups and government to protect and restore New Zealand’s native plants and animals.

The cost of shipping just three elephant is also as large as the annual biodiversity and biosecurity budgets of Auckland City and Wellington Regional Council to protect and enhance native ecosystems on land, in our rivers, estuaries and along our coasts, and prevent the spread of invasive pests that threaten our nation’s economy (see graph above).

The $4.65 million for just three elephants is also almost half as much as the Department of Conservation’s $10 million NZ Biodiversity Fund supporting biodiversity protection by landowners and communities nationwide.

Zoos make claims that elephants are important conservation advocates but the war for elephant is largely someone else’s war. We should not pretend to fight the world war for wildlife in trivial ways in our zoos while losing battles at home – like sending troops to a defend a country on the other side of the world while another threatens our own shores and families.

New Zealand’s biodiversity problems cannot be addressed by more elephants in zoos, but might be with ecological restoration and conservation advocacy based on native habitat and species in the places we live, work and play.

Our priorities for conservation advocacy could be better addressed by community restoration projects like Auckland’s Kaipatiki Project or Hamilton’s Gully Restoration, and mainland wildlife sanctuaries like Zealandia in Wellington. Instead of donating funds to move zoo elephants, consider donating to protect NZ Sea Lion or Maui’s Dolphin, eradicate mice on the Antipodes Islands (the Million Dollar Mouse Project), or plant the banks of your local stream with native vegetation for our native birds, reptiles, and fish.

Elephant are magnificent, but so is waking up to the call of kokako, summers swimming in clean beaches and rivers, or watching a Hector’s dolphin crest a wave. Only the last three, however, are unique to New Zealand. Keeping elephants in NZ does not make economic or conservation sense.

In a future post I will evaluate the reasons given by Zoos for having elephant in NZ and seek evidence for their claims.

The Greening of National: just add Gold - Wayne Linklater Nov 27

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Perhaps your Grandmother, like mine upon seeing my striped shirt, advised that “blue and green shouldn’t be seen, without a colour in between”. Fashion though, like the economy and its politics, is never constant – they are always reinventing themselves. Those clashing stripes have ‘gone out’ again but I think blue-green is set to become fashionable in the economies and politics of Aotearoa.

Conservation is portrayed in opposition to economic growth, and even freedoms and fairness that are central to our aspirations as communities [1] – especially our small communities whose economies were based on logging and mining forests. Increasingly, however, the protected landscape and its forests, lakes, rivers and wetlands are described by the services they provide to the same communities. In the provinces of New Zealand, conservation is finding itself on the agenda of the political right – blue and green without a colour in between.

Honorable Bill English (centre) speaks at the signing of an agreement between Hump Ridge Track Ltd. and Victoria University.

This month a team from Victoria University visited Tuatapere, Southland, and the Hump Ridge Track Ltd. Victoria is lending its expertise in the likes of tourism, restoration ecology, business, and wildlife management to a community making enormous strides in the new blue-green economy. Honourable Bill English, MP Clutha-Southland, and Mayor Frana Cardno, Southland District, oversaw the signature of an agreement between the two partners.

Neil Quigley (left, Victoria) and Stewart Weir (Chairman of Tuatapere Hump Track Ltd.) sign the agreement.

The Hump Ridge Track story is a lesson in the resilience of our nation’s provinces and their capacity to innovate. It is one of many examples of small communities fighting for survival in new economies that are dictated by big-city voters and big-city politicians. Declining support for indigenous forestry eventually ended logging in Waitutu Forests - NZ’s largest intact lowland beech-podocarp forest – during the 1990s. Tuatapere’s economy, based largely on exporting logs, was ‘gutted’.

Later, so the story goes, Helen Clark, Prime Minister of a Labour-led government with environmental sympathies and visiting Invercargill, offered Mayor Cardno a ride to Tuatapere. Never letting a chance go by, Mayor Cardno accepted and is said to have ‘bent’ Helen’s ear for the entire 90 minute journey. Southland’s feisty Mayor must have been convincing. Two months later $900,000 arrives from the Clark government to establish the Hump Ridge Track – tourist infrastructure for Tuatapere. And so its transformation to the new blue-green economy began. The forests of Waitutu are protected and will be improved as Tuatapere grows a tourism economy. In March this year the Hump Ridge Track won tourism gold – a Enviro Gold award (Qualmark) and milestone in Tuatapere’s new economy.

Our economy is increasingly based on the future of our environment – our clean water, wild places, and wildlife. Even Southland’s economy is 10-12% tourism and that portion is growing rapidly. In the long-suffering provinces of New Zealand ecological restoration and economic development are becoming partners. Think instead, Ecological Development and Economic Restoration. There is gold in them thar hills – tourist gold, Enviro Gold – hard won, but winnable nonetheless.

None of this should be new to Honourable Bill English or the National-led government. The promise is that ecological restoration will be seen as a tool in the development of New Zealand’s small-town economies in districts that are often, ironically, largely National Party constituencies. These are their people doing conservation.

Political commentators have identified the challenge to the National Party of finding credible coalition partners for the future. The demise of the far-right has laid National’s flank bare – undefended. But a National Party intent on seeing ecological restoration as part of its toolkit for economic development in its heartland might also steal Labour’s green stripes and attract a stronger environmental vote throughout New Zealand. The Green Party would necessarily follow.

First, however, National will need to allow its belief that New Zealand’s environment is in good shape to be challenged by the over-whelming scientific evidence to the contrary. Currently National seem hell-bent on self-delusion – ignoring ecological science, dismissing scientists, and defending a brand (100% Pure), rather than protecting the environment that makes the brand possible. Perhaps a new generation of leaders in National is required – I hope not. We need to make progress much faster than that.

Once upon a time, the political colour in between blue and green was red – Labour red. Increasingly, National has an opportunity to partner the environmental Green. My grandmother might also have observed that if you want to turn deepest blue, bright-bright green, just add gold. How right she was – tourism gold.


1          Fischer, D. Fairness and Freedom: A History of Two Open Societies: New Zealand and the United States.  (Oxford University Press, 2012).


Learning from US patent trends – innovation and synthesis in Aotearoa - Wayne Linklater Nov 23

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Innovating is hard and getting harder. You and I, apparently unlike any one before us, are ‘burdened by knowledge’. It is becoming more difficult to be novel – at least alone and early in life.

The burden of knowledge -
Intellectually deeper, conceptually wider

First-time innovators are older, required to be more specialised, and therefore, more likely to lodge a patent as a team. Benjamin Jones at Northwestern University IL, USA (now Kellogg School of Management) analysed 2.9 million patents issued by the US Patent and Trademark Office to reveal these trends and, what he described as, the ‘death of the renaissance man1.

Jones suggests the trends are a consequence of our facing a greater educational burden that delays innovation and drives specialisation to impair the capacity of individuals to innovate. Knowledge today is intellectually deeper and conceptually wider. Tomorrow it will be deeper and wider still.

Importantly, the ‘burden of knowledge’ may explain why an economy – a measure of communities solving problems and achieving aspirations – does not grow as fast as research effort expands. We can compensate by learning and living for longer, but most importantly, collaborating more, especially as inter-disciplinary teams towards synthesis.

Even when the returns to society are great, however, it can be difficult to generate synthesis because studies show that it requires the face-to-face collaboration of people from different disciplines, often competing institutions, not used to talking with each

The burden of knowledge

The burden of knowledge – an enormous network of information and participants

other. They have different priorities and languages – often using different words for the same things3. Nevertheless, individuals who participate in synthesis are more productive, increasingly collaborative, and more visible to peers and leaders in ways that positively influence careers3 – surely a strong motivator amongst NZ’s innovators in universities and research institutes.

New Zealand needs a Centre for Synthesis. Other countries have prioritised centres of ecological synthesis – perhaps because ecological science is at the heart of our most wicked problems – like NZ’s deteriorating rivers. Australia has one (ACEAS). The US has one (NCEAS). They drive innovation and problem solving in those countries – but we can do better.

A Centre for Synthesis Aotearoa – gold at the end of the rainbow

Recent changes in government science policy and funding mean the time is right for a nationally coordinated effort to establish a Centre for Synthesis. But ours should not be restricted to the sciences. We could make major advances in how knowledge and research contributes to New Zealand and the quality of lives of Kiwis if we could put all the human endeavours in one room towards solutions to our most important problems or highest aspirations as a country. As an ecologist, I’d welcome a conversation about these things with businesses, investors, lawyers, economists, psychologists, geographers, physicists, chemists, philosophers, historians…

A Centre for Synthesis should bring together researchers, investors, and those who can implement – businesses and government. New Zealand business agrees. Ruth Richardson, chair of KiwiNet, recently advocated (NBR 26th Oct. 2012) bringing research institutions, investors and businesses together in ‘market-facing’ Advanced Technology Institutes. The National government’s ‘Science Challenge’ could be a vehicle for such synthesis.

Its important, but also sounds like fun. The time is right.


1          Jones, B. F. The Burden of Knowledge and the “Death of the Renaissance Man”: Is Innovation Getting Harder? Review of Economic Studies 76, 283-317 (2009).

2          Carpenter, S. R. et al. Accelerate Synthesis in Ecology and Environmental Sciences. Bioscience 59, 699-701 (2009).

3          Hampton, S. E. & Parker, J. N. Collaboration and Productivity in Scientific Synthesis. Bioscience 61, 900-910(2011).

4          Rittel, H. & Webber, M. Dilemmas in a general theory of planning. Policy Sciences 4, 155-169 (1973).

5          Levin, K., Cashore, B., Bernstein, S. & Auld, G. Playing it forward: path dependency, progressive incrementalism, and the “Super Wicked” problem of global climate change. IOP conference Series: Earth and Environmental Science 6, 502002 (2009).


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