EcoLincNZ is a website maintained by the staff and students of the Department of Ecology at Lincoln University. It complements the official university website by giving a more up-to-date and in-depth view of what we do.
This collapse in the world’s insects has been reported in the news a lot recently but it always feels very distant. This couldn’t happen in Godzones, 100% pure New Zealand could it?
Insects have such a critical role in our lives, without them, crops would die; and species reliant on them would starve. Insects are part of a huge food web where they provide an essential role, eating smaller things and being eaten by bigger things. Missing this key connector in the food web will be disastrous. We are at a critical time in the future of our species and planet, it’s time to change and try to undo the damage we have done.
“Insects don’t need us we need them”
Why insect populations are plummeting—and why it matters National Geographic
Eucalyptus tortoise beetle Jon Sullivan (CC BY-NC 2.0)
With the first meeting in Paris for the Intergovernmental Science‑Policy Platform on Biodiversity and Ecosystem Services meeting early in 2019 (catchy name I know), heads of nations from across the world met to discuss the state of international biodiversity and produce its first report since 2005. This meeting reported on the issues facing our planet and the poor state of global diversity. As good as these conferences are I think the average person struggles to relate to the findings as they seem distant. For example, people know the Amazon is getting cut down at an alarming rate but will often think that’s far away and someone else’s problem. These problems must only exist in poor countries, not in clean green New Zealand.
A recent paper lead by Lincoln University researcher Mike Bowie brings the decline of insects into focus with a local context. The researches surveyed ground beetles in Ahuriri reserve in Banks Peninsula and compared it to a previous survey, 30 years earlier.
Ahuriri reserve Jon Sullivan (CC BY-NC 2.0)
Ground beetles were used as the focus for this study because, unlike other New Zealand insects, they are well described, and considered valuable for a measure of conservation and restoration success. In essence, the more ground beetles you have and the more species you find, the healthier your forest is.
The survey was done by using a trapping technique used in many insect surveys: pitfall trapping. A pitfall trap is essentially a cup in the ground for the ground beetles to fall into while walking around the forest floor. These pitfalls were set out in the forest for over a year and were cleared every 14 days. This method was the same as the previous study 30 years ago.
Mike found that, of the 14 different beetle species detected, 12 species had decreased and only 2 had increased over the three decades. Along with this, the total catch of beetles was 17% lower than the previous study.
The two species that had potentially increased were Holcaspis intermittens and the Banks Peninsula endemic species Holcaspis suteri but this increase was not statistically significant.
Of the six species absent from the latest survey, three of these are endemic to Banks Peninsula Onawea pantomelas, Zabronothus striatulus, and Bembidini sp., along with one endemic to the Canterbury region Oopterus laevicollis.
These reports are disturbing as they identify that the Ahuriri Reserve is one of the highest quality remnant forests on the Port Hills. All the species that they found in the 1981 study were present in the latest study with no new species present and the loss of six species. The loss of our endemic species is of the greatest concern.
What could be causing this decline?
In the reserve there has been the ongoing presence of mammal predators, this could have caused the decline of beetle numbers. There have been high catch numbers of possums, rodents, hedgehogs, mustelid, and cats, Even at lower numbers these mammals can significantly predate on ground-dwelling insect’s. Another possibility is that the habitat has caused a change in the distribution and counts of the beetles. Historic habitat loss can result in extinction that is delayed for many decades before local extinctions begin. We could be sitting on the verge of collapse due to the fragmented nature of our remaining reserves on the Port Hills. The poor ability for the large flightless ground beetles to move between theses reserves may have sealed their fate. This was seen in the collapse of ground beetles in Manawatu.
One of our native insects at risk to mammal predation Epitree (CC BY-NC 2.0)
Unlike in the movies we can’t rely on the environmental Avengers assembling and coming to save the day. We need to take heed of the warnings and look to conserve what we have left.
Luke Sutton is a postgraduate student in the Master of Pest Management. He wrote this article as part of his assessment for ECOL 608 Research Methods in Ecology.
When it comes to clothes, I am a man of simple means. I don’t much like buying them. I tend to hang onto clothes and wear them for years, until entropy does it thing or washing powder stops doing its thing. New clothes generally come via my wife or as hand-me-downs from a brother-in-law, who does not share my reluctance at getting new items, or, increasingly, from my sons. I sometimes might buy myself a teeshirt that appeals or underpants and socks when the present ones are beyond saving. I think that my eldest son has a similar perspective.
John Marris: not the most obvious place to look for beetles that live under bark. Image from the always well-dressed John Marris.
My other two sons are different. Youngest is a thrifter. He loves combing through thrift shops and second-hand stores to find quality vintage clothing (hey he could do that simply by opening my drawers!). I am not entirely clear on what makes one teeshirt a real find and another not worth a look. He has gotten good at it and now has set up a side business to being a uni student by selling his clothes that he finds online.
Middle son is also interested in clothes. However, he really can’t understand his younger brother’s fascination with the old. Middle likes new clothes. He does like finding a bargain though, and does spend a lot of time searching online for them. This skill has led into his current marketing job. Not to be outdone, middle has set up a side business in selling clothes under his own label (The Loop).
Both sons have a lot of clothes. This is all very alien to me. I guess I can see the appeal of finding a gem on an old clothes rack. That’s is similar to me prowling a second hand book store and finding a classic Tanith Lee or Patrick O’Brian that I don’t already have. I guess I can see the thrill of the new as well. That’s similar to me writing a blog article and putting it onto the net. But clothes?
Practically new! Image from Adrian Paterson
With my parent hat on, though, I am impressed by the fact that the boys have found a passion, and found an opportunity resulting from that passion, and implemented it.
As an evolutionary biologist I am always impressed by examples of organisms that have taken advantage of an opportunity and adapted into a new role. Some of my research has been on these types of organisms. For example, penguins and seals are descendants of land-living ancestors who made the most of an opportunity to become marine again and have prospered by this change.
A neat example has been found by John Marris (Lincoln University), David Hawke (Are Institute) and David Glenny (Manaaki Whenua Landcare Research). Beetles of the Brontini tribe are found all around the world and are almost always are found living under the bark of forest trees. There are abundant resources and safety to be found in this habitat and these beetles specialise in consuming fungi found there. As a consequence of living under bark, the beetles have a very flattened shape.
In an Ecology paper, a new species of this tribe is introduced, Protoden- drophagus antipodes Thomas 2003. A new species of beetle is hardly an earth-shattering event. However, in this case it is definitely not a run of mill species. Protodendrophagus antipodes is the only species of this global tribe to be found in the alpine zone. Specimens have been collected from along the New Zealand Southern Alps from above 1500m in altitude.
At this altitude there are very few food sources. There are certainly no trees and generally no plants either. So where do these beetles live? P. dendrophagus has made the most of its thin shape to find homes in narrow cracks in the rocks found in the alpine zone. The only viable food source that seems to be in these areas are lichens.
Protodendrophagus antipodes – a beetle that left the forest to live among the stones at high altitude. Image from John Marris.
Lichens are composite organisms made from algae or cyanobacteria living among filaments of fungi. In the alpine zone, and in the stony crevices where you find the beetle, there are multiple species and growth types of lichens. But how can you show that the beetles are actually eating the lichens?
A method called isotope analysis can identify the trophic level at which organisms live. Beetles that eat plants and lichens will have different isotope levels to those that eat other insects, for example.
A rocky outcrop with lots of crevices for P. dendrophagus to live in at Mt Hutt. Note that ski fields make sampling at altitude a lot easier to access! Image from John Marris.
P. dendrophagus has made the most of an opportunity. Given it’s adaptations to living under bark, the beetle has taken it’s slimness and invaded the alpine environments where small crevices form a somewhat similar habitat. The body shape for colonising small rock cracks is a pre-adaptation for this habitat. The beetle has taken it fungus eating diet and extended this to the rather more indigestible lichens (that are part-fungi). This has allowed this beetle species to extend its range in the stony zone above the vegetation zone for over 700 km along the Southern Alps.
The team gathered samples from beetles found at altitude at the Mt Hutt ski field. Likely food sources, including several different types of lichen, were also collected. The isotope analysis clearly showed that the alpine beetles were indeed eating the lichens. This a very rare food source for any beetle to eat, with just a handful recorded around the world.
One could say that the new habitat fits like a new glove. Or maybe an old vintage teeshirt.
Growing up on a farm meant that you were familiar with fire. There were always trimmings from shelter-belt hedges to drag into piles to make into bonfires. In autumn, there was barley stubble that was burned off to help get the paddocks ready for their next assignment. There were also internal fires to manage for keeping the house warm and even the barbecues were usually charcoal based.
Fire is an ongoing and increasing threat in dry ecosystems. Image by Adrian Paterson.
Burning stubble was always fun. There was an art to getting a quick and effective burn that didn’t spread out of the paddock and into places that you did not want it to be. You would wait for a still day and be poised around the boundary to put out sparks and wayward flames. Living in South Otago, with its plentiful rain, usually meant that the surrounding fields were lush and green. Fire was unlikely to catch hold in the moist neighbouring pastures and so they formed a natural firebreak to stop the spread of the burning. You would finish the day with a nicely burned paddock, a little too much smoke inhalation, and the sense of a job well done.
Living in Canterbury for the last couple of decades has changed my feelings about fire. Canterbury is a much dryer environment. Fires can get out of control and become very dangerous. In the last few years Lincoln was threatened by a wildfire that came within 1 km of the outskirts. The Port Hills had an immense wildfire that threatened the city and had me driving through raining ash to evacuate the in-laws. There have been numerous smaller fires that have nearly got out of control. In short, fires have the element of danger that was largely absent in South Otago. When I see stubble burn-offs now, or any smoke on the horizon, I can’t help but feel a little apprehensive.
A major issue with controlling fires in Canterbury compared with my childhood South Otago is the relative absence of green and lush vegetation surrounding drier areas. Because of the local climate, most vegetation in Canterbury is dry and very flammable by early autumn. There are few natural fire-breaks to halt the spread of a fire. However, there are always some plant species that have a lower flammability than others in any habitat. If we are going to manage future fires then it might help to have more of these species in the landscape. Fires coming up to these low flammability species may halt or at least be slowed enough to be dealt with by other means. This is what is meant by green firebreaks.
The concept of green firebreaks is not a new. It has been used as a fire management tool in various parts of the world for decades (if not longer). However, it is not a common approach as it requires a lot of pre-planning and potentially locking up land that could be producing something else. Still, in our increasingly fire-prone world, green firebreaks look like a good option.
China has a long history with greenbreaks for managing wildfires. There is evidence for firebreaks around 1000AD. A fifth of China is still forested and potentially prone to fires. This has led to the construction of over 350,000km of green firebreaks! Much of the research on greenbreak fire management has been done in China and has been unavailable to most of the science world (which is English language-based). Until now.
Xinglei in the field collecting plants to assess flammability.
In addition to alerting fire scientists to the existence of this research, Xinglei and his colleagues also summarised what has been found. Some examples: Green firebreak species (and the report identifies a number of useful species) tend to produce damper, more humid, understories with lots of fungi to break down leaf litter. Those that are effective should run perpendicular to likely advancing fires (usually perpendicular to the prevailing wind). Firebreaks on ridges are particularly effective. The width of a green firebreak should be at least 10m in most conditions. And so on.
Not only do green firebreaks work well in slowing and stopping wildfires but they are useful between fires for enhancing local biodiversity. Green firebreaks block radiant heat that can allow firefighters to approach fires more easily. Green firebreaks are relatively easy to maintain (certainly compared with bare-land firebreaks).
Green firebreaks on the top of ridges are very effective at halting fires (as seen here on the Port Hills). Image by Adrian Paterson.
Xinglei and colleagues were also able to identify areas in need of research. There is little information on where green firebreaks failed to work well. It would useful to have this information. Green firebreaks have mostly been used in a limited number of ecosystems and trials in different habitats and parts of the world would be useful. Finally, there has been little research into how green firebreaks could work in with other fire suppression methods.
The east coasts of New Zealand are likely to continue to become dryer and warmer, which will increase fire risk. Green firebreaks may be one useful solution that can make us all feel a little safer about living in these fire-prone habitats. The kind of solution that will make me feel a little more comfortable when I see smoke in the distance.
Recently, Julie and I shared our 25th wedding anniversary. It was a startling reminder of the onrushing progress of time. Sure, plenty has happened in those 25 years, children have been born and graduated from university, pets have come and gone, hundreds of students have been taught, research has been competed, earthquakes have been endured, cricket has be coached. But the wedding, as I am required to say, that most important day of my life, seems so recent. I remember it like it was yesterday. Until, that is, Julie and I started to look through our wedding albums.
The best day of my life. Also, no hats. Image from Adrian Paterson.
Staring out of these photos are younger versions of friends and family. We chuckled about these changes and moved on. But then there are the glimpses of people that didn’t really ring a bell. Who is that? Ooh was that so and so’s boyfriend at the time? There are absenses. I’m sure uncle and auntie X and Y came. Maybe not. There’s no evidence of them there. I know my brothers were their and there are plenty of my youngest. But where are the pictures of my other brother? Finally, he turns up in the side of a photo.
The photo albums of the wedding are a record of a time and place. They tell us who was there as they were captured by the camera. They don’t necessarily capture everyone who was there. They tell you something about behaviour. About fashions. Wedding hats are a fairly big thing, normally. But it appears that no-one wore one to our wedding! It was definitely hot and sunny enough, but clearly hats weren’t the thing that year. Overall, the photos are just snapshots of what occured in a very hot Masterton at St Lukes and Church/Solway Hotel on January 8th, 1994.
Cameras are an increasingly important and crucial piece of technology in our modern world, whether in CCTV footage or on your smart phone. Cameras are also becoming more frequently used in the world of science. In ecology and behaviour we make the most of the fact that taking a photo of an animal confirms that it was in that particular place at that particular time.
Obviously, how you set up a camera will determine how effective it is in detecting and recording an image of an animal. Too high off the ground and many animals will walk underneath a triggering beam. Too low and the radius of detection may be too small. How much light is required? How much vegetation should be removed to avoid false triggering? And so on.
There are times, though, when simply taking a picture is enough.
Sonam Lama, as part of his Master of International Nature Conservation research, is interested in the diversity of large mammals in eastern Nepal. Sonam has worked on Red Panda conservation for a decade and wanted to know which species the red pandas share their forest habitat with.
The elusive marbled cat… Image by Sonam Lama.
Sonam, working with Adrian Paterson and James Ross from Lincoln University and others from Nepalese-based NGOs, placed trail cameras out in an area of eastern Nepal on the border with India. Sonam set up 63 trail cameras in a grid pattern near the Khangchendzonga Biosphere Reserve. The cameras were left out for about a month at each site before they were moved on.
Overall, there were 3000 trap days spread throughout winter and spring over 100 sites. Over 5000 images of medium to large mammals were taken. The results have been published in the journal Nature Conservation. The most common mammals were the northern red muntjac Muntiacus vaginalis and the orange-bellied Himalayan squirrel Dremomys lokriah.
Of particular interest were the cat species that were detected, common leopard Panthera pardus, Asiatic golden-cat Catopuma temminckii and leopard cat Prionailurus bengalensis. A fourth species, the marbled cat Pardofelis marmorata, was also detected at one site on one day. The marbled cat is a near threatened species that has not been definitively recorded from Nepal before.
There were three images of the cat, with its characteristic large bushy tail. Three out of 5000 images of animals. In one sense this species barely registered its presence. In another, the confirmation that this species is present in mountain forest outside of a national park area and in Nepal, is a very exciting finding. Not finding a species doesn’t mean it isn’t actually there, just that you didn’t detect it. Detecting a species, on the other hand, is definitive. It is there.
The marbled cat is struggling throughout its range. This new detection extends its known range. It adds to the conservation load of Nepal but does imply that there may be more of these cats in the wild than we currently think.
Photographic images have a great power to record events in space and time, whether this is the style of wedding hats or the wandering of marbled cats.
Many other mammals were recorded on our cameras… red panda! Image from Sonam Lama.
Tim rocking the red shorts on a family bushwalk at Kaputar in the 1980s. Photo: Sandra Curran
First, there is family history: my great, great grandfather and great grandmother and then two great uncles farmed land in the foothills (Great Uncle Jim even regularly painted the mountains in his landscapes). We also used to go on family picnics and bushwalks there. Furthermore, the Nandewar Ranges, on which the park is situated, frames the northern horizon from my home town of Gunnedah, so Mt Kaputar was never far from my sight, or thoughts, growing up.
Second, I have spent a lot of time there professionally. This included: two weeks volunteering with the NSW National Parks and Wildlife Service on a survey of brush-tailed rock wallabies as a young undergrad; an amazing week as a Discovery Ranger for NPWS, leading guided bushwalks and spotlighting tours for the general public, while discovering just how much I loved teaching about nature and ecology; and many weeks in the nearby foothills and wider landscape as a PhD student examining the ecology of dry rainforest.
Finally, Mt Kaputar is incredibly diverse, in landscapes, plants and animals. It was formed 17-21 million years ago by several large volcanoes, and those remnants still dominate the area. The park ranges from 300 m altitude in the foothills to 1510 m on Mt Kaputar, causing a stark temperature gradient which is a blessed relief when the surrounding plains are baking in 40°C heat! These diverse habitats support many wonderful plants, animals and ecosystems, including dry rainforests (of three different types!) and bright pink slugs that can reach 20 cm in length.
Perusing sub-alpine vegetation with the kids at Dawsons Spring, Mt Kaputar NP. The green shrub is Coprosma hirtella and the tree is snow gum Eucalyptus pauciflora. Photo: Sandra Curran
During a recent trip to Mt Kaputar to show it to my wife and kids for the first time, I found another reason to love this park. There are plants and animals that represent a little piece of my adopted homeland of New Zealand. These native Australian species with NZ affinities were mostly found on the high-altitude Kaputar plateau, which has a much cooler and wetter climate than the surrounding plains. Certainly, the pleasant 23°C at the summit when we visited in Dec 2017 was more akin to summers in Canterbury than New South Wales!
So which plants and animals with NZ links did we see?
First, we saw some of the real icons of the NZ flora. Not only was there Coprosma (C. hirtella), but a divaricate species occurs there too (C. quadrifida). Divarication is a growth form which is disproportionately common in NZ, and attributed to adaptation to climatic extremes and/or defence against moa browsing. While one divaricate species found in Australia does not provide for robust debunking of any evolutionary hypothesis, it does add an interesting fact.
There was also Solanum aviculare (poroporo in NZ), growing profusely following a recent bushfire, just as it has been doing on the Port Hills of Christchurch. Dodonaea viscosa (our akeake, sticky hopbush across the ditch) is very common throughout the park (and elsewhere in Australia for that matter), but unlike NZ, where it grows to 12 m as a small tree, there it is usually only a shrub (albeit very dense to bash through following recent disturbance).
A quick search of the Atlas of Living Australia records for the park reveals many other names familiar in NZ, most found on the cool, wet Kaputar plateau: Leptospermum, Kunzea, Poa, Discaria, Leucopogon, Olearia, and Helichrysum. In my beloved dry rainforests there are Alectryon, Pittosporum and Blechnum. Mt Kaputar has tree ferns (Cyathea and Dicksonia) too, mainly on the wetter eastern slopes.
Mt Yulludunidah rises out of the lowlands in Mt Kaputar NP. Photo: Tim Curran
There are also fauna with NZ affinities. Besides the ubiquitous brush-tailed possum, another native Australian found in Mt Kaputar that now roams parts of NZ is the swamp wallaby. Finally, those fascinating bright pink slugs have links to Aotearoa, being close relatives of NZ leaf-veined slugs.
All these Trans-Tasman links have made me think of Mt Kaputar with even greater fondness, and I can’t wait to get back there!
The spread of corruption, particularly in plants, was a powerful idea that Tolkien used in his work, especially the Lord of the Rings, to show that something was wrong.
Goblins of Moria….. they love spoiled berries! Image by Adrian Paterson.
“Wide flats lay on either bank, shadowy meads filled with pale white flowers. Luminous these were too, beautiful and yet horrible of shape, like the demented forms in an uneasy dream; and they gave forth a faint sickening charnel-smell; an odour of rottenness filled the air. From mead to mead the bridge sprang. Figures stood there at its head, carven with cunning in forms human and bestial, but all corrupt and loathsome.”
Conversely, healthy plants and food was a strong theme that he used for showing that all was well.
Healthy juicy strawberries! It must be summer. Image by Edith Paterson.
“In a twinkling the table was laid. There was hot soup, cold meats, a blackberry tart, new loaves, slabs of butter, and half a ripe cheese: good plain food, as good as the Shire could show, and homelike enough to dispel the last of Sam’s misgivings (already much relieved by the excellence of the beer).”
It was no coincidence that one of the most overtly good and friendly characters in the Lord of the Rings was Tom Bombadil’s wife, Goldberry.
Tolkien used the idea to show the enormity of the task that was faced by the free-folk of Middle-earth, with Gandalf saying, “And for my part, I shall not wholly fail of my task, though Gondor should perish, if anything passes through this night that can still grow fair or bear fruit and flower again in days to come.”
And when it was all over and the world was set to rights what better way to show this than in my favourite quote from LotR, “Altogether 1420 in the Shire was a marvellous year. Not only was there wonderful sunshine and delicious rain, in due times and perfect measure, but there seemed something more: an air of richness and growth, and a gleam of a beauty beyond that of mortal summers that flicker and pass upon this Middle-earth. All the children born or begotten in that year, and there were many, were fair to see and strong, and most of them had a rich golden hair that had before been rare among hobbits. The fruit was so plentiful that young hobbits very nearly bathed in strawberries and cream; and later they sat on the lawns under the plum-trees and ate, until they had made piles of stones like small pyramids or the heaped skulls of a conqueror, and then they moved on. And no one was ill, and everyone was pleased. Except those who had to mow the grass.”
As someone who has to prepare and maintain the local Domain grass cricket pitch, that sentence always makes me smile.
Slightly spoiled strawberry. Image by Edith Paterson.
Why are these metaphors so effective for Tolkien?
We are coming up to our Southern Hemisphere Christmas soon. One of the best indications that our summer holidays and festive season is upon us is that local berries are starting to fruit. Christmas Day meals in New Zealand are often built around strawberries and raspberries (and sometimes blackberries and boysenberries). There are queues at local berry farms on Christmas Eve to grab punnets of these luscious, delicious berries. Some of my earliest memories of Christmas are about helping to remove the stalk and leaves off bowls of strawberries before adding the icing sugar.
I’m sure for Tolkien that berries and fruit represented the lazy, hazy days of summer as well (if not the Antipodean Christmas aspects). The berries only ripen and mature under good conditions. If things are not right then the berries spoil quickly. Who has not picked a bowl of berries only to find a day later that they have gone mouldy? Berries are then spoiled and not able to be eaten. All of that promise is gone. Things are not right with the world.
When Tolkien wants to show that darkness in stirring in Mirkwood he invokes the metaphor of rotting. “There lies the fastness of Southern Mirkwood,’ said Haldir. `It is clad in a forest of dark fir, where the trees strive one against another and their branches rot and wither.” When he wants to show happy times, such as when the entwives were active in the world, he invokes the metaphor of healthy fruit. “When Summer warms the hanging fruit and burns the berry brown; When straw is gold, and ear is white, and harvest comes to town; When honey spills, and apple swells, though wind be in the West, I’ll linger here beneath the Sun, because my land is best!”
Rotting strawberry! Image by Edith Paterson.
One of the common sources of spoilage of berries is from the downy mildew (Peronospora sparsa). This fungus can infect the leaves of fruits, like boysenberries, in early spring causing lesions, which then cause more infections. If fruits are infected then they prematurely redden and harden. Downy mildew can easily cause 50% losses in boysenberry crops (and 100% in some organic crops).
Eirian Jones and Herath Mudiyanselage were tasked with finding a way to reduce downy mildew in boysenberries. There is a particular issue in that planting material often is not disease-free. Fungicides are typically used to remove the downy mildew but heat treatment (where plants are held at a high temperature of 34oC or so for several weeks) has proven successful for some other pathogens.
Healthy raspberries! Image from Edith Paterson
Eirian and Herath and their colleagues took boysenberry plant samples and subjected them to either a heat treatment, a heat + fungicide treatment, or a control with no treatment. After the treatments, the plants were grown for several weeks. They were observed for spore growth as well as having samples taken for spore DNA to be detected.
They have reported their findings in the European Journal of Plant Pathology. The untreated controls had 100% infection but the other two treatments were around 17% infected. The fungicide played no obvious role, implying that a heat treatment was the main reason for success. One important outcome was that the heat treatment allowed the production of mature plants that were downy mildew-free. These plants would then produce healthy fruit.
This research has the potential to allow more crops of berries to grow and be harvested, fresh and healthy. It will majorly reduce the amount of spoilage that occurs. This can only add goodness to the world! Tolkien would have approved.
Publicising your work is becoming a common part of the scientist’s job. We are continually exhorted to connect with the public and to let them know what we are doing. This is not a bad idea, although most scientists are not trained to do this sort of thing, have no resources to do this anyway, and is seldom part of their job description and hence not really considered at promotion time. However, many of us try (this is why we have the EcoLincNZ blog after all).
Darwin certainly didn’t spend a lot of time in outreach. I guess his book on the Voyage of the Beagle was aimed at the general reader, and was a bestseller, but he seldom did anything like this again. No public talks, no bioblitzes, no school visits.
I can see him setting up a blog, though, where he put on his gems of natuaral history that he received from letters all around the world. Given his decade long work on barnacles, this might be a focus. Travel tips from his 6 years afloat might be another. But we know that for simply getting people to read articles, that lists are the best…. 10 reasons why natural selection will improve your life or Top tip for stopping evolution ravaging your lineage?
Back when I started as a fresh-faced lecturer at Lincoln University in the mid 90s I contributed to a third year class called Wildlife Management. Graham Hickling was the main lecturer and provided the heft of wildlife management. He had lots of hands-on experience in working with possums, stoats, rabbits and so on. I provided the more theoretical and conservation side of things, like how do we make a decision on which species to save.
Each year I would ask a question of the class. Which is the lesser of two evils: Pushing ahead with a method or technique when we haven’t done enough research to know whether it may help a species in question (and may even hinder it), or waiting to implement a method till after we know that it is a good thing to do (but risk losing the species or population)? Over eight years I surveyed about 240 students before the course was lost in a periodic restructuring. About 60% wanted to rush in while the other 40% wanted to be cautious and get it right. The proportions were about the same from year to year.
This always formed the basis of a good discussion between the two groups. Neither option is a good outcome. Most people in the rushing in group felt that doing something was always preferable to doing nothing. They also felt that most of the time we had a reasonably good feel for what would work, so why wait? The cautious group felt that getting it wrong would make things even worse, and possibly seal the fate of the species and that taking the time to get it right would usually be worth it.
Is there a correct answer here? Obviously it depends. Sometimes, things are so desperate that you need to do something right now. Usually, however, we have more time than we think. I have also seen plenty of examples of where testing really obvious ideas have found that, actually, things are not so obvious after all.
I was reminded of this by a study by Lincoln University’s Rebecca Dollery, Nick Dickinson and Mike Bowie. The trio had noticed that when people planted trees, especially in dry Canterbury, that they often put tree guards (a kind of plastic sleeve) around the trunk and a weed mat around the base. It is believed that the guards and mats protect the young tree from frosts and drying out as well as reducing weed growth close to the plant. There might also be some protection from mammal browsing.
Placing a guard and a mat on each young tree adds significant cost and labour to planting. With New Zealand wanting to plant 1 billion trees this becomes a much more important question. It is thought that putting the guards and mats on is a cost effective process because it decreases tree mortality. Seems obvious. Rebecca decided to test this.
In a dry site in North Canterbury at Te Whenua Hou Rebecca was able to plant about 1000 one year old kanuka and 180 Pomaderris plants. She tried two different tree guards, with and with out weed mats made from wool waste fibre. She also had plants that had no protection. Rebecca measured mortality over a year as well as soil moisture and temperature. Rebecca has published her PhD work in Ecological Management and Restoration.
Tree guards did seem to make a difference but not because of herbivory or frosts. It seemed that the the guards did stop the plants from drying out during summer. Weed mats, on the other hand, did not seem to do much at all. Rebecca was able to look at the costs associated with the different approaches. With the right tree guard, and factoring in survival of the kanuka, the cost was a third of doing nothing. However, with a different type of tree guard the cost was almost twice the cost of doing nothing! So, some obvious results and some not so obvious results.
With a billion trees to plant (at least!), these are not inconsequential savings or expenses (a billion times anything is a lot!). Rushing in could have very serious implications for the long term. In this case I am pleased that Rebecca, Nick and Mike have taken their time and tested the ‘obvious’.
Clearing an area of introduced pest species is a huge job. The goal of making New Zealand PredatorFree by 2050 is as aspirational as the moon-shot was in the 60s. Is it achievable? Of course it is. However, it require a LOT of resources, better ways of doing things that have worked so far, new ideas to do things that we haven’t done in the past even better in the future, lots of people, lots of buy-in from the general public. In short, a steadfast commitment for 30 years. Even if we don’t get there in the timeframe, reducing the range of predators by 50%, or the total numbers of predators by 80%, say, is still a tremendously good and useful outcome.
Quail Island/Otamahua in Lyttelton Harbour. King Billy Island is the small island to the right of Quail Island. Image from Mike Bowie.
How hard could it be? Let’s examine a small island in Lyttelton Harbour. Quail Island (Otamahua) is an 85ha island several hundred metres from the surrounding mainland shores. The island has a focus of a long-term attempt to eradicate introduced mammal pests and restore native vegetation and animal species for the last three decades. There have been a lot of successes with about 100 000 trees planted, and the eradication of cats, rabbits, hedgehogs, rats, possums, stoats, ferrets and weasels. So eradication can be achieved on a small island!
Well, almost. There are still plenty of mice. But mice are tiny and meek, surely they are not a problem? In the absence of other, larger rodents, mice tend to become more rat-like in their behaviour. On some islands they also increase in size and aggression and cause problems to large nesting bird species that they would normally keep away from. To make Quail Island all that it could be, the mice also need to be removed.
Mike Bowie has spent the last 25 years working towards the goal of restoring Quail Island. In a paper in the New Zealand Journal of Zoology he, and other colleagues, looks at the various attempts to remove mice from the island. Mice were almost removed accidentally in the late 90s. A large poisoning campaign using the toxin Pindone in cereal baits, was aimed at removing rabbits, which it did very successfully. As a side-effect the mice also ate the baits and their population was reduced to almost zero for three years before bouncing back.
Toxin drop on Quail Island. Image from Mike Bowie.
An attempt was made to remove all rodents in 2002. This time the toxin brodifacoum was delivered in rodent baits from bait stations placed in a 40 m grid across the island. This was very successful and eradicated rats from Quail Island. Mice were initially thought to have been eradicated but were detected again after just three months and their population quickly recovered.
Another attempt was made in 2009 to remove the mice. Even more planning and effort went into this event. A helicopter was used to spread brodifacoum baits over the entire island. This happened over two days, late July (where the helicopter flew in GIS programmed NE to SW transects of the island) and early August (where it flew the same course and then NW to SE). Intensive monitoring with tracking tunnels was then undertaken. By December of the following year the mice were back in good numbers.
One of the questions that Mike was interested in was whether the mice survived on the island or whether they recolonised from the mainland. King Billy Island lies between Quail Island and the mainland and might provide a stepping stone for mice to reinvade. Mike was able to take samples of mice from before and after the control operation, as well as from populations in the wider Christchurch area. He found that the mice on the island after the operation were genetically indistinguishable from before (but different to mice on the mainland). So it seemed that at least a handful of mice had survived the poison drop and that was enough to build up the population again.
Many lessons have been learned from the Quail Island control operation (and many others over the last two decades). Not least is that eradication requires a huge effort from a lot of people. The experience earned has allowed recent control operations to be even more meticulously planned and, ultimately, successful in eradicating mice from islands (see the recent removal of mice from the Antipodes). If the resources allow, then the next attempt on Quail Island is likely to be successful.
Removing mice from larger mainland areas is something that will remain out of our reach for quite some time. It is no coincidence that mice are not listed as one of the predators that we want to remove from New Zealand by 2050. If we are able to remove possums, stoats and rats by this time, the mice will indeed inherit this piece of the Earth.
It’s a common question that we often ask when meeting people for the first time, usually at parties or social events. For the last year or two I get a sinking feeling when I’m asked this. I usually know where it will end up.
“Well it is a toxin, so, yes, very effective at killing pest mammals.”
“But what about it getting into the water?”
“It’s water soluble and we have almost never detected it in water from areas of use, and when we have, it has been in vanishingly small traces that pose no threat. Your cup of tea and your pot of puha have more in them.”
“But doesn’t it kill everything where it’s used?”
“But people say that forests go silent after it has been used.”
“There may be non-target deaths in a 1080 operation (but even that has been difficult to show as a major issue). However, all of our follow-up monitoring show that the benefits come in the following years as natives are free from predation risk. Forests become a whole lot noisier than they were.”
“What about all those photos of dead kiwis!”
“Almost always these are kiwi that have been killed by dogs. The photos are misappropriated.”
“What about deer?”
“Yes it kills deer. Deer are pest species as well.”
“But what about those that like hunting?”
“Deer populations are very resilient. After all our efforts in 1080 control, deer are still found everywhere.”
“1080 kills dogs!”
“It certainly does. Dogs are incredibly susceptible to the 1080 toxin. That’s why we inform people about where we are using 1080 and not to take dogs there.”
“Doesn’t 1080 linger in the environment for ages?”
“Aren’t there other toxins we could use instead of 1080?”
“Of course, but not as many as you would think, as it is so expensive and time-consuming to register them and get them to market. Most of the options are a lot worse in their affects than 1080.”
More chatting. Image by Adrian Paterson.
“Some bioaccumulate, basically get passed around the food chain and can cause problems to all sorts of other organisms. Others are not as humane in the way the kill the animal. Others are more difficult to distribute into the bits of the environment that we need to get them to.”
“So 1080 is better than the other options?”
“Yes, at this stage.”
There is usually a pause for a swallow or two.
“I don’t like how we use helicopters to drop poison into our forests. Can’t we be more precise in how we give the pests the toxin?”
“We spend a lot of time and effort on this. For example, James and Elaine from Lincoln have been part of team developing an addition to a trap called a spitfire. This is aimed at targeting stoats. The trap has some tech in it that identifies when a stoat walks into it and then squirts a toxin called PAPP onto them. The stoat goes off and licks its coat clean, swallowing the toxin. Kills stoats but not other things that might wander in.”
“In theory. There are a lot of kinks to work out before this could be used for real.”
“Well why not use traps? That would be better than toxins.”
“Maybe. Traps are definitely another tool. We do use them a lot. Usually in small areas close to communities. Especially where community groups have a lot of manpower to help put out and maintain the traps. They can be very effective.”
“So lets use more!”
“Traps require a lot of work to put in place and then need to be regularly checked. This is usually not possible for large remote areas. They, also, have issues with killing non-target animals.”
“Can you make the traps better?”
“A lot of what we are doing is trying to make traps better. For example, with a bit of wireless tech you can get traps telling you when they have been activated. That helps with reducing how often someone needs to physically check a trap. We look at different designs, different ways of setting them up, different lures to attract the pest species and so on.”
“So traps might replace 1080?”
“Probably not. They will always struggle to work over large areas in difficult terrain.”
“Hmmmm. I’ve heard that we might be able to use genes to do something. Make them infertile. That sounds like a good 21st Century solution.”
“Ah yes, gene drives. It is theoretically possible to manipulate certain genes to help others, say those that cause infertility, to spread through a population. This could work over the whole pest population, ultimately reducing it to something very small.”
“It’s still very much a theory. There are all sorts of ethical issues. In the past, people have really objected to genetic manipulation of a species.”
“Yes, but these are pests after all.”
“And then there is the problem of making a decision for the rest of the world.”
“Let’s say we do this for possums and are successful. Can we honestly say we can contain it in New Zealand and that it won’t get to Australia and wipe out the possums there (which are native and threatened). Or worse, start doing it to the other native marsupials? You think trans-Tasman relations are not great at the moment….”
“But is possible that genes might be useful?”
“Absolutely. But not for a long time, even if all goes well.”
We usually pause for a drink at this point and often that’s the end. Sometimes it goes on.
Still more chatting. Image by Adrian Paterson.
“What about all these people that protest? They must have a point?”
“Well they certainly have beliefs. I’m reasonably confident that few of them have looked at the vast scientific literature on the 1080 topic. It’s always easy to scare people with ‘it will make you miscarry your baby’ or ‘it poisons the river systems’ or ‘it kills everything’. It’s much harder to get people to check the research that shows them ‘no it doesn’t’, ‘no it doesn’t’, and ‘no it doesn’t’. In fact I can show you a great site on your phone that has compiled a lot of the information, if you want?”
“No thanks, I don’t really trust those websites. I heard on facebook, though, that 1080 and pest control were just part of a Department of Conservation plot to [insert crazy scheme].”
“You do know that the majority of 1080 dropped in New Zealand is not to help DoC or conservation?”
“The majority of this effort is to stop Tb spread for our agriculture.”
If the conversation really starts to go downhill we can end up with the following.
“Yeah, but you can’t trust the science or the scientists.”
“And why is that?”
“Well, they get all this money so of course they are going to find no effect. It’s what the funders want.”
This is when I usually have to pause and take a deep breath. Once you reach the conspiracy zone it’s time to bail out, frantically try and catch your wife’s eye for help, fake a seizure, or something.
“Yeah, you know, DoC, big Pharma, [insert nebulous or absurd group].”
How to answer? I could say that ‘DoC is the most impoverished government department….’, or ‘I arrived here in my 2001 Toyota Estima, I wouldn’t mind seeing bit of that money!”, maybe “If there really was a conspiracy that included dozens of scientists and organisations, my ticket to fame and fortune would be in exposing it!”, perhaps “If I wanted money for my research then I would work on some crop or agricultural pest where they get a huge amount of support, not scrapping over the limited funding in the vertebrate pest management area!”. Usually, it’s not worth the effort.
“You may be right… they might be listening to us right now. Oh, it looks like my wife needs me. Nice to meet you, see you later.”
I then scurry off wondering whether I should go back to introducing myself with my other main research interest, evolutionary biology. Oh wait, that leads to a whole other conversation at parties that I’ll have to tell you about another time.