Archive Archive | New Zealand Geographic

Data

City sizes

This chart shows how population rankings for New Zealand settlements have changed over 130 years. Every place has its own rich story. The histories of Ōamaru and Hamilton, for example, are a study in contrasts. Ōamaru was a major agriculture service centre in 1891, with a population of 6294. This made it New Zealand’s eighth-largest urban area. The town grew through the first three-quarters of the 20th century, but at a slower rate than other towns. In 1974, the port closed and its population started to fall. In 2018, Ōamaru had 13,600 residents, down from a peak of 15,100 in 1976, and was the 28th-largest urban area. Hamilton was the country’s 17th-largest urban area in 1891, with a population of 2289. Many factors contributed to its rapid 20th-century expansion. Proximity to Auckland, its location on the main trunk line, and the Waikato River flowing through made it a major regional transport hub. The establishment of hospitals, government departments and a university, alongside the growth of Waikato dairying, further bolstered population growth. By 2018, Hamilton was the fourth-largest city in New Zealand, with a population of 205,505 people. Note that Napier and Hastings are counted as a single urban area due to their proximity.

Fixable

How to fix the Waikato peatlands

Don’t call them swamps. Bogs soak up and store more carbon than forests do, but when they’re drained and used for agriculture, that immense amount of carbon is slowly released.

Geography

Bloom or bust

Summer is the season of dahlia shows. Every weekend, enthusiasts assemble in town halls around the country to compete for the top prize: Champion of Champions. But participation in these shows is dwindling, and now the country’s top growers are seeking to pass on their expertise to a new generation of gardeners. Meanwhile, dahlia breeders continue to explore the plants’ hidden genes, producing ever newer, stranger, more extravagant cultivars.

Travel & Adventure

Have raft, will travel

Lightweight, inflatable boats are changing backcountry travel. Easier to paddle than a whitewater kayak, and more forgiving of mistakes, packrafts are opening up river sports to a wider audience.

Society

Reason to believe

The world is complex and confusing, and much of it doesn’t make sense. But there is information available at our fingertips—information of wildly varying quality. Sometimes, this information gets dangerous, especially in situations when we desperately want answers to questions that don’t have answers. So, how’s a rational person to tell truth from fiction these days? How do we, as a society, agree upon what’s true? And why have we been so catastrophically unable to agree in 2021?

Living World

The occupation

Wallabies may have evolved in Australia, but they’re so well suited to life in New Zealand that they have reached plague numbers for the second time in a century, eating their way through the landscapes of Canterbury and the Bay of Plenty and escaping from the containment zones created to hold them back.

Outdoors

The swim of her life

On February 17, 2020, 16-year-old Caitlin O’Reilly became the youngest person to claim the triple crown of marathon swimming in New Zealand. She had swum Cook Strait at 12 and crossed Lake Taupō at 14. All that remained was Foveaux Strait. O’Reilly set off from Rakiura/Stewart Island at 10.40am and powered north under the watchful eye of open-water swimming legend Phil Rush and skipper Zane Smith (whose father piloted Meda McKenzie across Foveaux in 1979). Despite encountering tidal chop near the finish, O’Reilly reached the mainland at sunset, covering the 27-kilometre distance in just over 10 hours. Only five other people have attained the triple crown; O’Reilly became interested in the feat after her coach mentioned swimming Cook Strait. “I thought, ‘Oh, that’s cool, maybe I’ll do that’,” she says, “and so I did.”

Partner Content

Spirit Level

Take out a green prescription on the West Coast.

Editorial

True or false?

The past year has revealed a lot about the human race and how we accumulate knowledge. Conspiracy theories have surged in popularity, and people have failed to agree on a set of facts—or a process for arriving at them. It wouldn’t be such a problem if we disagreed about subjective things, such as what makes good art. But we disagree about objective things, such as whether the virus that causes COVID-19 was manufactured by people (it wasn’t), or whether 5G cellular networks are tools for mind control (they aren’t). False information arises around things that we don’t see well or understand properly. Human health, in particular, is fertile ground for high-stakes misinformation. It has all the right ingredients—complexity, varied efficacy, diversity in culture, and eight billion personal experiences of treatment going right or wrong. Health also interfaces with science and technology at the highest level. We can kickstart someone’s heart, we can help them breathe with artificial lungs, but we can’t answer basic questions: Why do some people thrive, and some people do not? Why have some people recovered from COVID-19, while some remain desperately sick a year later, and others never even realised the virus was inside their bodies? Based on the machines we’ve invented and the mechanisms we understand, it seems as though we should be able to answer some of these other questions. But we can’t. And that leaves our species—one that craves certainty—with the one thing we struggle to accommodate: uncertainty. Belief arises where certainty is in short supply. And that’s where things get murky. Human health is deeply entangled with our beliefs. This is best illustrated by the placebo effect—the phenomenon where pretending to give a patient medicine or treatment makes them feel better. Study after study has shown that someone’s health can improve if they receive not treatment but only the ritual of treatment—the examination, the pill, the anaesthesia, the hospital stay. Even when someone knows the treatment is fake—the pill is sugar—they may improve. Equally at play is the nocebo effect, where negative expectations of a treatment lead to worsening health. We don’t entirely understand why this is. The placebo and nocebo effects are limited to us as individuals. But beliefs are contagious, and can spread through social groups, to helpful or harmful ends. In this issue, we look at misinformation, myth and belief. How do we form our beliefs? How do they change? We’re surrounded by things we take on faith, because it’s impossible for any of us to assess all the evidence about everything. We may trust methods, like science. We may trust institutions, if we perceive them as helpful. We definitely trust our friends and communities. We know in groups, just like we live in groups. I don’t really like the thought that my ideas aren’t my own, that perhaps I haven’t selected them for their objective rightness. But the notion that I act entirely without influence is a dangerous one. Recognising what influences us is one thing. Shifting our understanding of the world is another. Hayden Donnell’s story on page 54 looks at people who’ve undergone epistemological transformations—they changed their minds. They moved from an understanding of the world based on false ideas to one based on evidence. It’s a more difficult transition than it sounds, and it was made possible by the empathy of others—the greatest influencer of all.

Geo News

A very sneaky virus

The first cases of COVID-19 arrived in New Zealand on February 26, 2020—or so we thought. Now, testing has revealed the virus began to spread slightly earlier. A traveller from Italy arrived on February 23, then became ill with what seemed like the flu. So did six members of their household. They didn’t qualify for COVID-19 testing at the time, but followed advice to isolate and recovered. Six months later, one member of the group came down with a cold, had a nasal swab, and returned a weak positive result for COVID-19. Further testing revealed the man already had antibodies for the virus, so researchers concluded that the viral genetic material detected was residue from a past infection (and that the man probably wasn’t contagious). For researchers, it reveals that the virus can still be detected in the body up to 201 days after an initial infection. This is now the first known case—and cluster—in New Zealand.

Geo News

All in the mind

Could taking tiny, regular doses of psychedelic drugs enhance your mental health? Not any more than a sugar pill, according to the largest placebo-controlled study on “microdosing” to date. Microdosing involves taking substances such as LSD or psilocybin (the hallucinogenic compound in magic mushrooms) a couple of times a week, at around 10 per cent of a typical recreational dose. It has recently surged in popularity, as the dose is too small to cause hallucinations, but is purported to improve mood, creativity and psychological wellbeing. One hundred and ninety-one people volunteered for the study, administered by researchers in the United Kingdom. Over four weeks, the participants either took drugs or a placebo, without knowing which they were ingesting. After four weeks, those taking psychedelics reported significantly improved wellbeing and life satisfaction. So did the people taking inactive capsules. There were no significant differences between the two groups—both experienced the same positive effects. The researchers suggest the benefits of microdosing arise not from drugs, but from the power of our own expectations.

Geo News

Ears on the ocean

The ocean is awash with noise. The clicking of shrimp snapping their claws, the crunching of reef fish grazing, the rumble of a vessel passing overhead—sound travels fast underwater, and in all directions. For animals that rely on sound for communication, such as whales, a cluttered soundscape can be stressful, causing them to change their behaviour. To hear what whales hear—and map where they go—researchers deployed four acoustic recorders in the waters around central New Zealand, collecting soundwaves at various frequencies. The recorders detected the ethereal calls of four whale species: pygmy blue, Antarctic blue, humpback and Antarctic minke whales. Pygmy blue whales were abundant in the South Taranaki Bight, with some visiting Kaikōura in autumn. The other species passed by New Zealand on their annual migration between the tropics and Antarctica. The sound recorders also captured the whooshing ambient background of rain, tides, waves and wind, even earthquakes. Human-generated noises from seismic surveying and ships were also common, and at times overlapped with the whales’ calls. The researchers say this audio information helps identify places in the ocean where human noise might be limited for the whales’ benefit. Whales aren’t the only animals facing hearing problems. Growing up in acidic waters can cause hearing damage in snapper, according to a different study by New Zealand and Australian researchers. Young snapper raised in conditions with elevated carbon dioxide levels were significantly less sensitive to low-frequency sounds. This diminished ability was attributed to changes in the structure of their ear bones and brain chemistry resulting from increased acidity. Hearing is critical for many fish species, playing an important role across their lives: from larval fish deciding where to settle, to individuals synchronising for spawning, to making contact with others.

Geo News

Fish dine by moonlight

The phases of the moon affect how fast baby fish grow, a new study has found. Ecologist Jeffrey Shima from Victoria University of Wellington and colleagues found sixbar wrasse larvae grew fastest during the last quarter of the moon—when the first half of the night is dark, and the second part is bright. That’s because when reef fish release their larvae, these float out into the open ocean to feed. There, they meet the mass migration that takes place every night as millions of fish and plankton rise from the deep to feed, then sink before dawn to hide in the dark. Baby sixbar wrasse feed on plankton, which rise more quickly than their predators. But when predators such as lanternfish arrive at the surface, they use their bioluminescent tummies to camouflage themselves against the moon’s light and sneak up on the wrasse. Shima’s hypothesis is that when the moon is full, it’s too bright for plankton to feel safe and for predators to properly conceal themselves, so neither rise all the way to the surface. That leaves the wrasse hungry, but safe. On dark nights, there’s plenty of food—and plenty of lanternfish. But during the last quarter, when the moon rises at midnight, the plankton have already reached the surface, and by the time the predators join them, it’s too bright for them to hunt successfully. The wrasse larvae feed freely and grow more quickly. “This has really big implications for explaining why we see a lot of variation in the survival rates of baby fishes,” says Shima. “If you have months that are more cloudy than average, that might have serious consequences.” Artificial lights from cities may also disrupt these natural cycles.

Geo News

Fish on meds

Human antidepressants flow into waterways after passing through the body, where they affect the behaviour of fish. Australian researchers created tanks of water polluted with one of the world’s most commonly prescribed antidepressants, fluoxetine (also known as Prozac), at concentrations that have already been detected in waterways around the world. Over two years, the scientists raised generations of guppies in the contaminated water. They found that the antidepressant made guppies act more similarly—even low concentrations resulted in the fishes’ behaviour becoming more conformist. Variety is crucial to survival—it helps animals adapt to change.

Geo News

Fish tracer

Small-scale fisheries land half of the world’s catch—but not much is known about the 40 million people involved in them, or how many fish they’re pulling out of the sea. This means governments make policies based on inaccurate estimates of catch and consumption, which can lead to unsustainable fisheries. A group of international researchers, including Shaun Wilkinson from Victoria University in Wellington, have developed a free smartphone app using open-source software that fishers, government managers, and researchers can use to accurately track catches in real time. They tested the app in Timor-Leste between 2016 and 2018, co-designing aspects of it with fishers and local fisheries managers, and in 2019 the Timorese government adopted the app as its national fisheries monitoring system. Called PeskAAS—the name references the word for fisheries in Tetum, the national language of Timor-Leste—the app can be used to collect detailed data on species caught, fishing methods used, habitat fished in, time spent fishing, and the price of the fish. Since 2016, nearly 60,000 fishing trips in Timor-Leste have been tracked using the technology, with catches recorded for nearly 30,000 of them, and the data has been incorporated into new fisheries laws. The researchers hope the technology will be widely adopted by other countries—though they acknowledge that it is designed for boat-based fisheries, compounding the invisibility of women fishers, who often collect seafood near the shore and on foot.

Geo News

Glow-in-the-dark sharks

In January 2020, Jérôme Mallefet went looking for glowing sharks on the Chatham Rise, off the east coast of the South Island. As researchers on the NIWA ship Tangaroa hauled up trawl nets full of hoki for their annual fisheries survey, Mallefet kept his eyes peeled for bycatch. He and colleagues collected more than 600 deep-sea sharks, representing three species, and transferred 24 into tanks in the wet lab. As the ship pitched and rolled, they photographed the sharks in the dark. They discovered that all three shark species had the ability to glow: two small lanternsharks, and the kitefin shark, Dalatias licha, which reaches up to 1.8 metres in length. That makes the kitefin shark the largest light-producing creature—with a spine—that has ever been found. Mallefet, an expert in bioluminescence from the Catholic University of Louvain in Belgium, says other studies suggest that around ten per cent of the Earth’s approximately 540 shark species can glow. So why do they do it? Partly to recognise each other in their deepwater home, as each species lights up in a particular way. It may help males and females align for reproduction. And glowing can also make the sharks invisible. “These guys are living in the twilight zone, where there is a bluish faint light coming from the surface,” says Mallefet. Seen from beneath, the animals’ bodies appear as silhouettes against the light. But when the kitefin shark illuminates its entire belly with a blue glow, it blends into the light from above. “Suddenly you disappear—that’s how counter-illumination works.” Their dorsal fin also glows—but why remains a mystery. Other recent studies have shown that as many as three-quarters of marine animals in the water column have the ability to make their own light. “Bioluminescence is so widespread, it must have a really critical role for the survival of these organisms down there,” says Mallefet. “The way they communicate, the way they reproduce—bioluminescence plays a role in it, and we are only just discovering that now. “It must be glowing Christmas trees everywhere down there, that’s for sure.”

Geo News

Jealous dogs

A study has found that dogs exhibit jealous behaviour and can imagine their owners’ ‘infidelity’ even when they can’t see it. Researchers at the University of Auckland recruited dog owners and placed a chest-high barrier between the humans and their furry friends. The owners had to wear noise-cancelling headphones and goggles to avoid giving any unintentional cues to their pets. The barrier was opened for long enough that the dogs could see there was either a social rival—a realistic-looking fake dog—or a fur-covered cylinder near their owner. The dogs pulled much harder on their leads when their owners were patting the fake dog compared with the control box—and significantly, they did this even when the barrier was closed and they could no longer see the fake dog, says study lead Amalia Bastos, a doctoral candidate at Auckland. “This is the first time that anyone has shown that dogs can actually imagine social interactions they can’t see—they’re sort of playing a little movie in their head.” No-one had ever tested whether dogs could do this before, Bastos says. “I think people tend to underestimate what dogs are capable of in terms of their social intelligence.” Other studies have been divided over what dogs’ jealous behaviour actually looks like, and therefore whether there really is any evidence for it—but these researchers took a lead from the science on jealousy in infant humans. Human babies and toddlers consistently tend to try to get closer to their mother when jealous of her attention going elsewhere—and the new study shows that dogs exhibit a similar response, says Bastos. “We’ve definitely shown jealous behaviour in dogs. But whether that means they’re subjectively experiencing jealousy in the way we do is a much harder question to answer.” The results give scientific weight to what many dog-owners have long suspected — surveys have shown that people believe their pets do get jealous. But Bastos hopes the findings may also help change attitudes towards animals and how we treat them. “They might be actually more similar to us than we give them credit for.”

Geo News

Sewage surveillance

To find out how much New Zealanders are drinking and smoking, a group of researchers turned to sewage. Across one week in March 2018, researchers collected samples from seven treatment plants in three regions: Auckland, the Bay of Plenty and Canterbury. They measured the levels of alcohol and nicotine metabolites, the molecules excreted after your body breaks down the drinks and smokes. Results were adjusted for population to determine how much was consumed per person. From a pile of excrement came a treasure trove of scientific insights. Across all regions, and especially in urban areas, people drank more alcohol on the weekends, whereas smoking remained consistent throughout the week. Cantabrians and Bay of Plenty residents consumed more nicotine and drank more than Aucklanders. Nicotine consumption was higher in economically deprived neighbourhoods. Nicotine and alcohol aren’t the only substances sought by scientists in sewage. Government scientists also monitor wastewater for traces of COVID-19—a possible early-warning system for undetected community transmission—and for drugs, to help authorities map drug use.

Geo News

The mystery kiwi

The first kiwi sent from New Zealand to Europe arrived in England around 1812. Its insides had been removed, its skin and feathers preserved, and its little body flattened into an un-lifelike shape. It was a tokoeka/South Island brown kiwi, and it became the holotype of the species, the individual animal associated with the scientific name given to it in 1813, Apteryx australis. Where exactly the specimen came from was a mystery. Naturalists assumed it was collected in Fiordland’s Dusky Sound. Now, cutting-edge ancient-DNA techniques have revealed its true origins—which means new scientific names will need to be found for three other groups of tokoeka. In 2017, Canterbury Museum curators Paul Scofield and Vanesa De Pietri visited the holotype at the World Museum Liverpool, where they were given a sample of the bird’s skin the size of a fingernail clipping. Back in New Zealand, Scofield and colleagues mapped the kiwi’s mitochondrial and nuclear DNA, then compared the sequences with the genomes of living kiwi. The results showed the specimen was genetically distinct from the Fiordland tokoeka, meaning it wasn’t from Fiordland at all. Instead, it was from the world’s southernmost kiwi population, on Rakiura/Stewart Island. Researchers checked their finding against the historical record, and it stacked up. When the kiwi specimen was collected in 1811, Fiordland seal populations had been cleaned out, and the few sealing gangs remaining had moved to the northern side of Foveaux Strait. Using shipping data from early newspapers, Scofield’s team established that just one vessel, the Sydney Cove, was sealing near South Cape on Rakiura at the time. One of those sealers probably caught the kiwi. When the sealing crew landed in Sydney, they sold seal and kiwi skins to Andrew Barclay, the captain of a convict ship and former privateer (during the Napoleonic Wars, he obtained a licence from the British monarchy to board and sink French ships). Barclay sailed to China, where the seal skins would be made into leather for top hats, then continued to London. The kiwi specimen ended up in the private collection of George Shaw, keeper of zoology at the British Museum, who bestowed its scientific name. Now that we know the kiwi came from Rakiura, according to the rules of taxonomy, the Rakiura population must now take the Apteryx australis name—an appropriate one, as australis means southern. Research continues into whether the genetically distinct populations of tokoeka on Rakiura and in southern Fiordland, northern Fiordland and Haast are separate species or subspecies. Once that’s been figured out, the three other groups will need new scientific names—an opportunity to use Māori terms for these taonga.

Geo News

Tracks of the tohorā

In issue #166, New Zealand Geographic covered a research project to track tohorā/southern right whales and learn where they swim over the summer. The results are in. As this issue went to print, only one whale’s transmitter was still functioning, that of Wiremu, the whale named after New Zealand Geographic journalist Bill Morris. Wiremu/Bill is the light blue line travelling along the coast of Antarctica.

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