Unwanted aliens: is a predator-free New Zealand realistic by 2050?

In a moment of half-baked madness worthy of Donald Trump, the New Zealand Government has announced a plan to make the nation predator-free by 2050. As can be imagined this statement has attracted a wide range of opinions, even from across various conservation groups. These vary from the extremely optimistic viewpoint of Forest and Bird advocacy manager Kevin Hackwell, who claims it is achievable even earlier, to the Green Party's conservation spokesman Kevin Hague, who publicised a University of Auckland study estimating the project's budget at an astonishing if not untenable NZ$9 billion.

With the government prepared to provide just one-third of the plan's funding, it's difficult to imagine which private sector companies would be willing to supply the lion's share over the next three decades. As expected, the response of New Zealand's political opposition has been to pour very cold water on the plan, including the claim that no nation has ever managed to wipe out its population of rats (Hamelin and its Pied Piper notwithstanding).

One of the most essential questions is what is defined as a pest in the context of this proposal?  The relevant Department of Conservation (DoC) page names three principle animal pests: possums, rats and stoats, with a further page expanding the list to other introduced animals and freshwater fish, including cats and dogs (both domestic and feral). Some of the species listed were deliberate introductions, mainly in the Nineteenth Century, whilst others came in accidentally under the radar - New Zealand's biosecurity protocols not always being as draconian as they are now.

A few statistics offer a frightening idea of the scale required: as of 2001 it was estimated that there were seventy million possums in New Zealand, eating 21,000 tonnes of vegetation every night. Needless to say, much of this material consists of endemic species such as pohutukawa and southern rata trees. This then has a knock-on effect for the native fauna that feeds or nests on these species, which of course is in addition to being direct prey for the possum.

Although cats and dogs might be thought of more as pets than pests, even in low numbers they can be devastating to native wildlife. A classic example is the extinction of the Stephens Island wren thanks to a number of feral cats, whilst it is thought that one stray dog managed to kill more than five hundred large brown kiwi in the Waitangi State Forest in less than a year.

DoC's Battle for our Birds scheme relies on aerial drops of poison and ground baits/traps to eradicate the key non-native pests. This year their target area was almost 900,000 hectares; to give an indication of the increase in scale necessary for a nationwide eradication, New Zealand is close to 27 million hectares in total. Perhaps the much-misused term 'paradigm shift' could be safely applied in this circumstance?

At this point it should be mentioned that there are varied opinions as to what the government's planned outcome is. After all, there have been humans living in New Zealand for over seven centuries, so there is little chance of any except the most remote locales returning to a pristine ‘natural' wilderness, even if we knew exactly what that meant. Having said that, the Pleistocene Park project in Russia is attempting something along similar lines. A small region of north Siberian tundra is being converted into glacial period steppe, using musk ox and other large animals as surrogates for extinct mega fauna such as mammoth and woolly rhinoceros. The resulting flora appears to be much more diverse and interesting than the unmanaged wilderness surrounding it, which is ironically the antithesis of what one would expect or hope for with untouched versus deliberately altered landscapes!

Then there's the scale issue: whilst possums, rats and mustelids are relatively easy to track and observe, small species such as wasps and argentine ants are far more difficult to locate, never mind eradicate. Although they don't inflict as much obvious damage to the native flora and fauna, they can nonetheless cause fundamental changes to the ecosystem. Wasps for example eat honeydew, which is an important food source for lizards and native birds such as kaka.

It isn't just insects that would be tricky to wipe out. The rainbow or ‘plague' skink was accidentally introduced from Australia about half a century ago and now seems ubiquitous in Auckland; I've seen it everywhere from volcanos to paddocks, gardens to garages, even inside a bookshop. Thanks to much faster reproduction and maturation rates than native equivalents, it appears to be rapidly out-competing them.

One issue that prevents a complete turning back of the clock is the extinction of dozens of species since the arrival of humans in the country. How can the ecosystem, especially food webs, maintain a long-term balance with key species missing? No-one is suggesting we bring in cassowaries to replace the nine species of moa. Of course, being large creatures they were probably none too numerous, yet there is an hypothesis that they may have been involved in an evolutionary arms race with lancewood, the juvenile trees being well-protected against moa browsing them.

Therefore any attempt to preserve a largely native ecosystem will need to ensure the food webs are fully-functional, with plenty of indigenous pollinators such as short-tailed bats and kereru (native pigeon). Key native species need to identified and preserved just as much as introduced ones removed. This in turn begs the obvious point that since evolution is an ongoing process, are we attempting to freeze the environment at a particular snapshot in time rather than allowing nature to take its course? Even accounting for punctuated equilibrium, natural selection hasn't suddenly stopped in New Zealand any more than it has elsewhere.

The pest-free project will presumably need to tackle species in a certain order, since if mustelids and feral cats are eliminated then rats will proliferate, whilst without rats as prey, the former species will be forced to look for alternative food sources instead; doubtless native birds would form the mainstay of this.

As I have discussed elsewhere, it shouldn't just be the enemies of the native poster species that are targeted. There are plenty of critters less famous than parrot kakapo and ancient reptile tuatara that deserve some attention too, with the endemic weta an obvious example (over twenty percent of its species are currently under threat). Invertebrates play an almost unknown role in nutrient recycling and waste disposal, as well as appearing on the menu of more conspicuous animals. Considering that the takahe, the largest species of swamp hen, was thought extinct for half a century, perhaps we shouldn't be surprised about how little is known concerning the size and condition of native creepy crawly populations. However small and insignificant we might judge them, we ignore their loss at our peril.

Also often overlooked are the native freshwater creatures. Competition comes in the form of the high number of invasive species that compete or predate on them. A key example is the aggressive gambusia, a Mexican fish introduced to eat all the mosquito larvae - which of course it fails to do. Interestingly enough, the DoC website excludes some introduced species from its list of pests: salmon and trout for example are categorised as 'sports fish'. Therefore is economics the government's primary motive for the pest eradication plan, rather than good old-fashioned conservation for the sake of it? After all, the extremely rare takahe was once given second place to herds of elk that had been introduced to serve as a big game animal.

There may be something in this. Mainstream politicians are renowned for their lip service commitment to environmental issues. Could it be that in the wake of the highly negative stories earlier this year concerning exceeded fishing quotas and river pollution, the government is fighting to redeem New Zealand's '100% Pure' brand image?  In addition, agriculture might benefit from an increase in native species' populations. An outstanding example of the latter is shown by a Federated Farmers of NZ estimate that native bees provide pollination services to the tune of NZ$4.5 billion per year!

Finally, we get to flora. As Bec Stanley, a curator at Auckland's Botanic Gardens, is keen to point out, the majority of people have plant blindness compared to their interest in animals. There are thought to around three invasive plant species for every four natives, with old man's beard, gorse, ragwort and nightshade being amongst the best-known culprits. These can smother and kill native plants, thus depriving indigenous animals of food. Despite being vital to the ecosystem, the war on introduced vegetation really seems to be underdeveloped compared to that against non-native animals.

It doesn't take much to upset the balance of at least a local-scale environment. The surviving remnants of mighty kauri forest are currently facing a disease thought to be caused by an introduced water-mould pathogen, a clear case of David conquering Goliath. Without careful consideration, the project to rid New Zealand of introduced pest species could end up doing more harm than good. The motives are potentially dubious and the research chronically under-funded. It remains to be seen whether there is the willpower to see it through or if it is just one more piece of political rhetoric that evaporates by the next election. Personally, I'm in favour of the idea, but uncertain of how realistic it is. Regardless, the citizens of New Zealand need to do their best, lest many more species join the ranks of moa, huia, adzebill and many, many others. After all, who wants their children living in an environment dominated by feral pigeons, rats and possum?

Resurrecting megafauna: the various problems of de-extinction

The record-breaking success of Jurassic World proves that if there's anything a lot of people want to see in the animal kingdom it is species that are both large and fierce. Unfortunately, in these post-glacial times that type of fauna has been much reduced and will no doubt wane even further - not that I particularly wish to encounter an apex predator at close quarters, you understand.

Hollywood, of course, has much to answer for. There was plenty of poor science in the original Jurassic Park movie - the use of gap-filling frog DNA being a far worse crime in my book than the over-sized velociraptors (think Achillobator and similar species) but the most recent film in the franchise has pointedly ignored the advances in dinosaur knowledge made in the intervening period. Perhaps a CGI test of a feathered T-Rex looked just to comical?

In contrast, the amount of publically-available material discussing de-extinction has increased exponentially in the two decades since Jurassic Park was released, with the line between fact and fiction well and truly blurred. That's not to say that an enormous amount hasn't been learned about the DNA of extinct species during this period. I recently watched a rather good documentary on the National Geographic channel (yes, it does occasionally happen) about the one-month old baby mammoth Lyuba, recovered in Siberia almost forty-two thousand years after she died. The amount of genetic information that has been recovered from mammoths is now extremely comprehensive, but then they were alive until almost yesterday at geological timescales. Needless to say the further back in time a creature existed, the more problematic it is to retrieve any genetic material.

A lot has been written about the methods that have been, or could in the near future, be used to resurrect ancient animals. Some procedures involve the use of contemporary species as surrogate parents, such as elephants standing in for mother mammoths. But it seems fair to say that all such projects are finding difficulties rather greater than originally planned. One common misconception is that any resurrected animal would be a pure example of its kind. Even the numerous frozen mammoth carcasses have failed to supply anywhere near a complete genome and of course it isn't just a case of filling in gaps as per a jigsaw puzzle: one primary issue is how to know where each fragment fits into the whole. Our knowledge of genetics may have advanced enormously since Watson and Crick's landmark 1953 paper, but genetic engineering is still incredibly difficult even with species that are alive today. After all, Dolly the sheep wasn't a pure clone, but had nuclear DNA from one donor and mitochondrial DNA from another.

Therefore instead of resurrecting extinct species we would be engineering hybrid genomes. Jurassic World took this process to the extreme with Indominus rex, a giant hybrid of many species including cuttlefish! Some research suggests that the most of the original genes of any species over a million years old – and therefore including all dinosaurs – might never be recovered. Something  terrible lizard-ish may be built one day, but it would be closer to say, a chicken, with added teeth, a long bony tail and a serious attitude problem. In fact, George Lucas has been a key funder of the chickenosaurus project with aims along these lines. Let's hope he doesn't start building an army of them, totally obedient clones, ready for world domination…oh no, that was fiction, wasn't it?

But if – or more likely, when – creating variants of extinct species becomes possible, should we even attempt it? Apart from the formidable technical challenges, a lot of the drive behind it seems to be for populating glorified wildlife parks, or even worse, game reserves. The mock TV documentary series Prehistoric Park for example only contained large animals from various periods, frequently fierce carnivores, with no attention given to less conspicuous creatures or indeed flora. This gee-whiz mentality seems to follow a lot of the material written about de-extinction, masking some very serious long-term issues in favour of something akin to old-style menageries. Jurassic Park, in fact.

A big question that would be near impossible to answer in advance is whether such a species would be able to thrive or even survive in a climate far removed from the original, unless there was major genetic engineering just for such adaptive purposes. Again, the further back the animal lived, the less likely it is that there is a contemporary habitat close to the original. It may be possible to recreate glacial steppes suitable for some mammoth species, but what about the Earth of ten million or one hundred million years ago? Prehistoric Park got around the issue for its Carboniferous megafauna by housing them in a high oxygen enclosure, which is certainly a solution, if something of a fire hazard!

Any newly-created animal will lack the symbiotic microbial fauna and flora of the original era, but I've not seen much that tackles this issue. I suppose there could be a multi-stage process, starting with deliberate injections of material in vitro (or via the host /mother). But once the animal is born it will have to exist with whatever the local environment/habitat has to offer. The chimerical nature of the organism may help provide a solution, but again this takes the creature even further from the original.

Then there is the rather important issue of food. To his credit, Michael Crichton suggested in Jurassic Park that herbivorous dinosaurs swallowing gizzard stones might accidentally eat berries that their metabolism couldn't handle. It would be extremely expensive to maintain compounds large enough for megafauna that are constantly kept free of wind-blown, bird-dropped and otherwise invasive material dangerous to the animals.

If the hybrids were allowed free reign, what if they escaped or were able to breed naturally? Given a breeding population (as opposed to say, sterilised clones) evolution via natural selection may lead them in a new direction. It would be wise to consider them as an integral part of the ecosystem into which they are placed, remembering Darwin's metaphor of ten thousand sharp wedges. Is there a possibility that they could out-compete modern species or in some other way exacerbate the contemporary high rate of extinction?

I've previously discussed the dangers of deliberate introduction of foreign species for biological control purposes: surely introducing engineered hybrids of extinct species is the ultimate example of this process? Or would there be a complete ban on natural reproduction for resurrected species, with each generation hand-reared from a bank of genetic material? At this point it should be clear that it isn't just the nomenclature that is confusing.

Some research has been undertaken to investigate the de-extinction of species whose demise during the past few centuries can clearly be blamed on humans, obvious examples being the Tasmanian tiger and the nine species of New Zealand moa. It could be claimed that this has more to do with alleviating guilt than serving a useful purpose (assuaging crimes against the ecosystem, as it were) but even in these cases the funds might be better turned towards more pressing issues. After all, two-thirds of amphibian species are currently endangered, largely due to direct human action. That's not to say that such money would then be available, since for example, a wealthy business tycoon who wants to sponsor mammoth resurrection - and they do exist - wouldn't necessarily transfer their funding to engineering hardier crops or revitalising declining pollinating insect species such as bees.

As it happens, even species that existed until a few hundred years ago have left little useable fragments of DNA, the dodo being a prime example. That's not to say that it won't one day be retrievable, as shown by the quagga, which was the first extinct species to have its DNA recovered, via a Nineteenth Century pelt.

As Jeff Goldman's chaos mathematician says in Jurassic Park, "scientists were so preoccupied with whether or not they could that they didn't stop to think if they should". Isn't that a useful consideration for any endeavour into the unknown? If there's one thing that biological control has shown, it is to expect the unexpected. The Romans may have enjoyed animal circuses, but we need to think carefully before we create a high-tech living spectacle without rather more consideration to the wider picture than appears to currently be the case.

Dung roaming: a controversial approach to cleaning up New Zealand's cattle waste

Although I've already discussed the dangers of using biological control in various countries, a couple of recent events suggested I should write an update that concentrates on one particular example in New Zealand. I've mentioned elsewhere that my local reserve in Auckland is home to a large number of non-native species, from Australian eucalyptus trees and the associated (but accidentally imported) Emperor Gum moth, to California quail and Mexican gambusia fish. But having seen rainbow skink in my local environs, including a neighbour's garden, I was surprised to learn last week they are not native but yet another unplanned Australian import. Sure enough, the 1947 classic Powell's Native Animals of New Zealand makes no mention of the species in the page on the indigenous common skink and copper skink.

Earlier this year I read Quinn Berentson's superb Moa: the life and death of New Zealand's legendary bird, which lists fifty-eight avian species as having become extinct since humans first arrived in the country less than a thousand years ago. And of course this decimation of native fauna and flora may not yet have ended, with NIWA for example fighting a rear guard action against unwanted marine incomers such as polychaete worms arriving on ship's hulls and in discharged ballast water. Various sources suggest that well over one hundred introduced species of land animals, birds and fish are now widespread in New Zealand: what chance does the native ecosystem stand against this onslaught?

To add insult to injury, I recently read an OECD chart delineating business spend on research and development as a percentage of GDP, and was shocked to find that New Zealand was fourth from bottom of twenty-six nations, coming below western Europe, South Korea, Japan, Australia, Canada and the USA. Are our captains of industry really so short-sighted? As a country that depends extremely heavily on its dairy industry - an industry that is currently in dire straits - it seems sensible to invest a large amount of R&D in this sector. But alongside the eco-friendly solutions such as minimising methane emissions, there has been a new programme of biological control aimed at one particular side effect of dairy farming, namely the enormous amounts of cattle dung produced.

Across the Tasman, Australia has already been working on a similar scheme for the past half century, deliberately introducing numerous species of non-native dung beetles. New Zealand, home to over ten million cattle in a 3:2 dairy-to-meat ratio, obviously has issues with bovine manure management. Due to the lack of native ruminants the country's fifteen indigenous dung beetle species have evolved to mostly inhabit forests rather than grazing land.

There are various reasons why speeding up the rate of dung decomposition would improve farm land and the landscape in general, from preventing mineral imbalance in the soil and contamination of waterways to reduction in animal-infesting parasites such as nematode worms. But is it worth the risk to the greater environment, considering the dismal track record of biological control schemes around the world?

The new project is not the first time such insects have arrived in the country: in addition to three species accidentally imported from Australia and South Africa from the late Nineteenth Century onwards, the Mexican dung beetle (Copris incertus) was deliberately introduced into three areas in the 1950s but only thrived in the warm Northland climate. It is the scale of the new research that has set it apart: following caged field trials, the past two years has seen the widespread introduction of eleven non-native species across seven regions on both North and South Islands.

Bodies such as the Institute of Environmental Science and Research (ESR) have investigated the potential dangers to human health and the local ecology, even testing if possums, carriers of bovine tuberculosis, might see the exotic insects as a new food source. Even so, some professional scientists have deemed it a biosecurity disaster and one can see their point: using data from other countries' programmes is hardly a fool-proof comparison, considering the profoundly different indigenous ecosystems of Australia and New Zealand.

As a child I heard about the food chain or pyramid, but this is something of a misnomer. Just as natural selection works with bushes rather than linear progression, so there are food webs consisting of a complex series of trophic interactions. Although exotic dung beetles are unlikely to displace their native counterparts due to lack of shared environments, it is possible that other native species of grassland-living insects could suffer, such as humble earthworms. The problem is that without testing in various regions over long periods of time, it isn't viable to rule out such side consequences. Yet it isn't possible to undertake such tests without release into the wild: do we have something of a catch-22?

Having said that, there are no obvious signs that Australia's long-established dung beetle programme has had anything like the deleterious effects of its other biological control schemes, such as the cane toad fiasco. But then fifty years is a very short time in ecological timeframes and what to the casual glance of a farmer appears to be equilibrium could be apocalyptic at dung beetle scale. I wish the project good luck, but cannot help feeling that having received far more than its fair share of obnoxious aliens, New Zealand is the last place that needs yet more exotic species introduced onto its green and pleasant land.

Unprofessional endeavours: amateur paleontology in New Zealand

There is currently an exhibition touring around New Zealand called Dinosaur Footprints: A Story of Discovery, which as its name suggests concerns traces of our much-beloved prehistoric beasts. Besides being the nation's first dinosaur footprints (known to science, that is) the story of their discovery is all the more interesting for their having been found by accident. In this particular case the discoverer was a professional geologist but in many cases New Zealand's great fossil discoveries have been equally serendipitous findings by amateurs.

Whilst New Zealand science is comparatively young, amateurs have always played a pivotal role in both the discovery and analysis of native fossils. Although the beginnings of Kiwi paleontology appear rather haphazard (see for example Quinn Berentson's superb Moa: The life and death of New Zealand's legendary bird for details on Walter Mantell, Julius von Haast and co.) the involvement of amateurs has far from diminished even today.

Although I've previously discussed non-professional fossicking before and even written a more New Zealand-focused April Fool's post, the more I've learnt about the Kiwi give-it-a-go approach the more I've wanted to write about the discipline from a local perspective.  Having undertaken three fossil hunts over the past year in the North Island (two successful, one a complete failure) I also now have some practical experience to aid me.

New Zealand fossil finds from 2014

There are several amateur New Zealand palaeontologists who have made key discoveries, perhaps the best known being Dave Allen and the late Joan Wiffen. The latter found the first dinosaur material in the country, as well as some Mesozoic marine reptile remains. And this was after many professionals claimed there was unlikely to be any such material in New Zealand! Dave Allen has also made some key finds and is occasionally even asked by the likes of Te Papa for advice.  Clearly, in a nation served by less than thirty full-time professionals, such people are able to make a big difference. To show it isn't just the province of adults, in 2006 children from the Hamilton Junior Naturalists Club found bones from a 35 million year old giant penguin, which just shows what a mind even semi-prepared for such material can discover.

One of the common misapprehensions about fossil hunting is that it involves excavation in the same way as is often required in archaeology. In fact, many fossils can be found eroding out of cliffs or roadside cuttings, or even found in loose material on beaches. Therefore there is a finite period between fossils being easy to spot and becoming worn down into useless fragments just by natural erosion, never mind man-made development. One report for example, suggests that weather will severely erode over fifty known fossil locations in the next half century. As such, it seems to make common sense that the more people trained to spot fossil material and be able to carefully extract it, the better. The late evolutionary biologist Stephen Jay Gould, an expert on snails, once lamented that whilst in the Great Rift Valley he was unable to spot any of the hominin remains but instead homed in on the copious fossil snails that everyone else had missed!

This isn't to say that amateurs should have carte blanche. About one third of New Zealand's fossiliferous locations are protected from extraction due to the importance of the material. However, that still leaves at least thirty to forty sites that are easy for non-professionals to access whilst also allowing the removal of fossils. Amateurs are well served by both books and websites that supply details of locales and common fossil species. James Crampton and Marianna Terezow's family-friendly The Kiwi Fossil Hunter's Handbook is particularly good for the former whilst the same authors along with three others have written A Photographic Guide to Fossils of New Zealand, an invaluable resource. For the more serious amateurs, finds details can be found at resources such as the Fossil Record Electronic Database (FRED), which has over 86,000 locations. So all in all, there's plenty of help for the casual fossicker.

In addition to the argument that the greater the number of fossil hunters, the greater the opportunity to discover material before it is eroded, there is also the problem that the lack of professionals is apparently causing the loss of knowledge in basic areas such as taxonomy. According to James Crampton and Roger Cooper's 2010 report The State of Paleontology in New Zealand, around 40% of Cenezoic mollusc species have yet to be fully described. They state that there are still large areas of the country that have not been fully explored by palaeontologists so who knows what other surprises may lurking in the deep bush or hidden river valley?

There's even the slim chance that the involvement of amateurs may stimulate public interest and activity in important associated fields, such as the protection of endangered species, environmental pollution, sustainability and the promotion of science in general over woolly thinking. After all, it appears most politicians would rather side with big business than the greens, so only continuous and concerted efforts from a fair-sized element of the general public will likely aid the future state of the nation's environment. And that's not something any of us can afford to ignore, regardless of whether you are interested in the remains of organisms that have long since turned to stone.