A matter of value

It’s not always about the facts (11 minute read)

My article this week is slightly different. It’s linked to disinformation, but it’s a topic I’ve been thinking about in relation to my current work, a case where I’m not convinced that claims of science denial actually hold up.

In writing Friday’s article about Round Island, I found myself fact-checking the information I’d been given when I was working as a volunteer for the Mauritian Wildlife Foundation. As I mentioned on Friday, we used to rotate all our cargo going onto Round Island – this was to kill any eggs of the Asian house gecko, if they hadn’t been detected while we were packing.

As I wrote the article, I wondered whether this was actually true. Were reptile eggs really killed by rotation?

What I learned was intriguing. The information I had been given could best be described as common knowledge. People who bred reptiles believed this advice and shared it – for example through online groups. But scientific studies gave varying answers on whether it was true – some types of reptile eggs survived rotation, some didn’t. I found a recent paper which reviewed the evidence and tested it with a type of snake. Their results showed that rotation killed the eggs of some but not all reptiles.

The Asian house gecko wasn’t one of the species tested. So, was the Mauritian Wildlife Foundation right to make us rotate our cargo?

For my day job over the last couple of years, I’ve been researching biosecurity decision-making. This is exactly the kind of question which decision-makers face every day. The evidence doesn’t give us an answer. Rotating the eggs reduces the survival of some reptiles, but not others. Nobody’s tested the Asian house gecko (or at least they haven’t published any studies I can locate). What’s the right thing to do?

These questions fascinate me. One person will give one answer, someone else will say the opposite. Why?

The answer comes down to how we feel about uncertainty. On the one hand, someone might make the argument that it’s pointless doing something when we don’t know that it works. On the other, someone else might argue that if there is a chance it will help, we should do it. Neither is right or wrong – it’s a matter of values.

We only spent about five minutes rotating the cargo, so it’s my opinion that we were doing the right thing. To me, it was worth the small amount of time on the chance it would help. But I acknowledge that this is an opinion and not a fact. It’s also my opinion that if it took a considerable amount of time to rotate the cargo, it would be a good idea to do some simple tests and see if rotation actually had an effect. But again, someone else could look at the same facts and legitimately come to a different conclusion.

The difference between facts and values is something I’ve been forced to examine in my years working on invasive species and biosecurity. There’s a lot of science explaining the impacts of invasive species and how to manage them, but behind that science are some value-based assumptions that many of those who work in the field give little thought to.

It’s a fact that the arrival of mammals such as rats, stoats, goats and possums resulted in the decline, and sometimes extinction, of many animals and plants native to New Zealand. That many of these native plants and animals are found nowhere but New Zealand can also be considered a fact. There are different opinions on how to classify species, a valid debate, but it’s stretching credibility to claim that there’s anything like a kākāpō or a kiwi or pekeketua (New Zealand’s native frogs) anywhere else in the world.

It's a matter of opinion, though, whether this matters.

To me, such a statement is confronting. Of course it matters. I’ve been passionate about nature since I first brought a snail into the house and gave it a name. I’ve been fascinated by New Zealand’s unique species since I watched TV programmes like Wild South and Wildtrack from the Natural History Unit of Television New Zealand. These programmes showed me native species I had no chance of seeing in suburban Auckland.

I think I cried when I saw the episode “Island eaten by rats”. I’ve linked to the video, which tells the awful story of Taukihepa or Big South Cape Island. In the early 1960s, it was the last home of three bird species and a bat, as well as many other birds, reptiles and insects. When rats got onto the island from a fishing boat moored nearby, most of the native species on the island were wiped out. Of the birds and bats found nowhere else, only one species, the tīeke or South Island saddleback, could be saved.

Over the next forty years, New Zealand conservationists learned how to eradicate rats from islands such as Taukihepa. In 2006, the rats were finally eradicated, and the tīeke, which had grown in number on other rat-free islands, was reintroduced. The island has recovered, somewhat, but of course there’s nothing to be done about the bat and two birds which are gone forever.

Image credit: Joshua J. Cotten on Unsplash

There’s no question to me that eradicating rats from Taukihepa was the right thing to do. It’s a strongly-held belief for me that we should protect New Zealand’s unique native species and do what we can to allow them to thrive in the land which was their home long before people ever reached here. The song of the tūī brightens my day in a way the song of the thrush never does. The company of a pīwakawaka or fantail cheers me more than the company of a sparrow. When I hear the call of our large forest parrot, the kākā, flying above my house, I’m delighted. For most of my life, the kākā was a species I never saw except on visits to remote islands, or in an aviary. Now, I see or hear them every day.

But here is where things get tricky. The only reason that the tūī and pīwakawaka are so abundant and that kākā now live in my neighbourhood is because there is extensive control of predators such as rats, stoats and possums in nearby areas of forest. This means I value the life of a kākā over that of a rat or a stoat. I don’t think that this is an unreasonable view. The stoat is native to most of the temperate Northern Hemisphere. The rat species found in New Zealand are all widespread. The kākā is found nowhere but New Zealand.

However, as part of my current work, I’ve been looking into conflicts over invasive species management. Sometimes I come across papers from people who start from fundamentally different values. For example, I read a paper from someone who writes about ethics and considers controlling invasive species ethically wrong. While they (grudgingly) acknowledge that species introduced to a new area can cause harm to other species, their starting point is that all animal life has equal intrinsic value and that in most cases killing an animal to achieve a particular goal is wrong. This view is no more right or wrong than mine – it’s an example of someone having different values.

Rats might seem to be a species which is difficult to defend, but it’s actually more complicated than that. I still remember an ecology lecture from the early 1990s, where a Māori researcher came and spoke to us about rats. It was a revelation to me, and I’ve never forgotten it. She talked about the history of Europe, and the connection between rats and diseases such as the plague. Europeans, she explained, had a deeply ingrained and entirely justified aversion to rats, because of that link to disease. But the kiore, a species of rat native to south-east Asia, was carried by Polynesian explorers throughout the Pacific. The rats they carried with them were not diseased and were valued for food. So Māori had an equally justified affection for the kiore, especially as it was almost entirely wiped out on the mainland of New Zealand when the European rat species arrived.

This lecture made me realise that while I was rightly concerned about the impacts of rats on native birds, my concerns were also coloured by these cultural perceptions.

The different views on the value of rats led to a drawn-out conflict between New Zealand’s Department of Conservation and the traditional (and legitimate) owners of Hauturu-ō-Toi, or Little Barrier Island, Ngāti Manuhiri, who were forcibly evicted in 1896. Hauturu-ō-Toi was one of few places kiore could be found, but it was also a crucially important island for the conservation of species found nowhere else, such as the wētāpunga, arguably the world’s heaviest insect, and the hihi or stitchbird. The Department of Conservation wanted to eradicate kiore. Ngāti Manuhiri argued that there could be other options for management, which the Department of Conservation refused to consider. In the end, they reached an agreement that some kiore would be transferred to another island, and the eradication went ahead in 2004. But it seems it was a difficult process to reach that point.

Differing opinions on invasive species have led to debates on the pages of academic journals, where researchers have questioned whether there is such a thing as invasive species denial. They have linked it with science denial, which isn’t always a helpful term, because people don’t tend to think that they are denying science when they hold beliefs which are counter to accepted scientific evidence. It’s just that they trust different sources of evidence. Nonetheless, science denial is a valid way of describing the views of people such as the former South African president, who, contrary to all the evidence, claimed (and continues to claim) that HIV did not cause AIDS. His government’s policies meant that lifesaving treatment was much slower to reach people who needed it than in other south and east African countries with less-developed infrastructure and fewer resources.

However, much of what I’ve read about the debate on invasive species suggests that it isn’t quite the same thing. The academic debate seems to be centred around two areas. The first is the area I’ve mentioned already – values. In academic circles, the study of invasive species is usually considered a branch of conservation biology. Researchers who study invasive species are working from an assumption that it’s important to protect plants and animals in the places where they come from, and not just in zoos and gardens, or tiny remote islands. A number of critics are coming from a different set of beliefs, such as that the origins of a species shouldn’t mean anything in terms of value.

Frequently, the arguments seem to be between two groups of people stating two sets of facts, as if only one can be correct. On the one hand, there are those who talk about the harm caused by invasive species. On the other, there are those who say that they aren’t necessarily harmful, that they can also have positive impacts. Sometimes, it isn’t clear whether they are referring to species classed as invasive, or all species which have been introduced from other areas. It doesn’t matter, though. The fact is that they are correct – many introduced species, including invasive species, have positive benefits.

New Zealand wouldn’t have much of an economy without introduced species, and some of those valuable introduced species, such as deer, goats and pine trees, are considered invasive. Does the fact that they are economically important mean that they are not also harmful in some circumstances? Certainly not. Nor does the fact they are harmful negate their value.

It’s even possible for invasive species to provide benefits for endangered native species. I previously wrote about the role that gorse, the bane of New Zealand’s farmers, played in protecting the last remaining individuals of an endangered wētā. That’s far from the only example. Brush wattle on Tiritiri Matangi was a valuable food source for the native birds on the island. And when I worked for the Department of Conservation, I sometimes recommended that certain invasive species in certain sites should not be controlled as they did more good than harm.

As I’ve been reading about the academic debate, it has struck me that people may misinterpret their opponents’ arguments and slant the evidence to support their view, but they aren’t lying. I wouldn’t call it disinformation or misinformation. But, when I started digging into social media, there were some wild claims. In New Zealand, no topic brings out the invasive species misinformation (and likely disinformation) like control of pests such as possums with the poison 1080. There’s a whole world of conspiracy, in which people claim plots by the government, Bill Gates, the illuminati and Jewish banks, among other things.

I’ll write about this one day, because it’s fascinating, as well as disturbing. And it’s important for the survival of New Zealand’s native species – which is something I care about deeply.

But something else nags at me. If I love native birds so much, why do I have two cats? Here, I find myself entangled in one of New Zealand’s thorniest conservation issues. Cats, including pet cats, kill many native species. But they also kill rats and mice. On balance, are my cats a problem? Again, I need to write about this, but now is not the time. Nonetheless, I will say one thing – it reminds me that some of the values and beliefs I hold contradict each other. I honestly cannot imagine living without a cat in my home.

Debates about environmental issues always seem to be a mix of facts and values. At times, people dispute what the facts are. At times, people fundamentally differ about what matters. In my experience, though, the conversations are always better when people recognise the difference between the two.