Felicity Jones and Mark Smith, Massey University Press, $85, October 9
Man versus beast, in a public swimming pool.
A new book showcases the dust and drama of mountain biking in New Zealand.
Need a mobile home? An incubation chamber? Dinner? Hundreds of species have hit on an elegant solution: find a nice juicy critter—and turn it into a zombie.
Daniel B Thomas, Jeffrey H Robinson, Daphne E Lee, The University of Otago
In New Zealand’s national parks and remote areas, conservation managers cull feral cats to save many bird, reptile and invertebrate lives. That’s not possible in urban nature reserves, where there’s a risk of extinguishing someone’s beloved pet. But these refuges are often significant habitats for bitterns, crakes, fernbirds, dotterels, penguins and kiwi—native birds that cats scare from their nests, or dismember and proudly display on doormats. Searching for solutions, Manaaki Whenua/Landcare Research ecologist Sze-Wing Yiu and her colleagues set up camera traps over summer in six reserves—two each in Auckland, Wellington and Christchurch. It was a first step to see what neighbourhood cats were getting up to. They found that while lots of cats visited the reserves—40 snapped camera-trap selfies in Wellington’s northern Miramar Peninsula, for instance—not all of them are killers. In fact, just two individuals were responsible for the four unequivocal kills observed during the study. One cat played for 25 minutes with a pārera, or native grey duck, in Styx Mill Conservation Reserve, Christchurch. And at West Auckland’s Harbourview-Orangihina Park, the cat pictured here—which appears to have a collar—carried off three pūkeko chicks one after the other (in broad daylight, implying that keeping cats indoors at night doesn’t necessarily save birds). Then there was the cat that liked to walk at low tide around the predator-proof fence at the Omaha Shorebird Sanctuary, north of Auckland, to visit dotterel nests. The cameras didn’t capture any violence, but the nosy-parker freaked out the dotterel parents: the five monitored nests it visited all failed. In theory, such feline outliers are actually good news, says Yiu—identifying and managing a few serial-killer individuals is probably more practical and socially acceptable than widespread control. (So far, for instance, it’s proven difficult to convince New Zealanders to keep their cats indoors; see ‘Our love affair with cats’, Issue 167.) Yiu believes the Green Party’s proposed new law requiring cats be registered and microchipped is a crucial next step. This study, she notes, is part of a wider project investigating whether cats can be deterred by recorded sounds, such as human voices or dogs barking. “Change is totally possible,” Yiu says. “We just need to push people to try new things.”
OE McLeod with RM Briggs, CE Conway and O Ishizuka Geoscience Society of New Zealand, $75
Orchids are everywhere. New Zealand has well over 100 species; worldwide there are tens of thousands. “The only places where you don’t see orchids are in the Earth’s deserts and Antarctica,” says Carlos Lehnebach, an orchid botanist at Te Papa. Also, we’re obsessed with them. “There are a lot of people who are nutty about orchids,” says Lehnebach’s colleague, evolutionary biologist Lara Shepherd. We love their vast range of flower colours and shapes, their collectability, and their bizarre pollination strategies (a whiff of carrion, anyone?) Yet orchids can still surprise us. In December 2020, when Shepherd sent Lehnebach a photo of a common leek orchid she’d found in Taranaki, he thought, “Woah, that’s a weirdo orchid.” Closer inspection—and Shepherd’s DNA analysis of a tiny chunk of leaf—revealed it was an entirely different species. “The sepals and petals are longer and more elegant, and it’s a slender plant,” he says. “The common leek orchid is a little bit chunkier, stockier, and the petals are shorter.” To fully describe the species, the scientists combed through dried herbarium specimens, century-old accounts from naturalists, and the intricate drawings of Bruce Irwin, a botanical illustrator and orchid lover who died in 2012. (His sketch at right was originally made in pencil; we’ve colourised it.) The diversity of the native leek orchids hadn’t escaped Irwin; he described this one as “slender and elegant”. In a nod to him, Lehnebach and Shepherd named their new weirdo Prasophyllum elegantissimum, or the extremely elegant leek orchid. Does that make the common leek orchid graceless, next to its supermodel cousin? Lehnebach is loath to fat-shame any organism, he says. “It does make you think about why thin is associated with elegance.” The new species is widespread—it’s been found from the Central North Island to Otago—but also rare, making up a tiny percentage of leek orchid specimens and iNaturalist records. “It has a preference for wetlands,” says Shepherd, “and New Zealand wetlands are so screwed up.” More discoveries are coming. The pair are working through a list of 20 more potentially new native orchid species. But it’ll take years. “There aren’t enough botanists in the country, and it takes a lot of effort to formally describe a species,” says Lehnebach.
Solutions to some of our most pressing problems have been waving at us from under the sea, all along.
For Jay Kuethe, there’s just something about Passiflora.
For all their showiness, tree ferns are extraordinary survivors. They hold their secrets close—but now, scientists are finding new ways to unfurl them.
The enviable upsides of having something sticking out of your backside.
Laura Ryan was studying the visual systems of fish when a spate of shark attacks at her favourite Perth surf spot got her thinking—why do these apex predators confuse tasteless humans with delicious seals? Great whites are by far the deadliest shark species to humans, though fatal attacks are extremely rare—there are only 59 recorded deaths in history, and we frequently share the same waters with them without incident. These sharks also see the world in blurry black-and-white. When they look up and see a long, dark shape silhouetted against the surface, their brains can have trouble distinguishing person from prey. “This is a really difficult task if you have a shark visual system,” says Ryan, a neurobiologist at Macquarie University in Sydney. So she and her colleagues set about making a swimmer or surfer look less like a seal. Many ocean animals use a camouflage technique called counterillumination—a form of bioluminescence where animals shine light from their bellies to help them blend in with the brighter surface when viewed from below. Ryan’s team stuck LED lights onto foam seal decoys and spent 500 hours towing them behind a boat off a great white hotspot in South Africa. They found that the brightest lights—brighter even than the sunlit background—and horizontal stripes of light were the most effective deterrents. It’s a form of “dazzle camouflage”, Ryan says, an optical illusion that both breaks up an object’s outline and interferes with the shark’s ability to detect motion. But don’t go sticking glowsticks onto your surfboard or wetsuit just yet, Ryan says. That’s because the exact brightness seems to be crucial—the sharks did attack some decoys fitted with dim lights—and the scientists need to check that the trick works when an object is still, like a surfer waiting in the line-up. They also need to make sure the lights don’t actually attract tiger or bull sharks, which see the world quite differently. Those experiments are now under way, as is a glowed-up surfboard prototype—an invention Ryan hopes will one day protect both humans and sharks.
Our summers are getting hotter, but electric fans are not always the answer—even if they make you feel cooler. Electric fans work by blowing cooler air across our skin and enhancing the evaporation of our sweat. Cheap and convenient, they often sell out in heatwaves. But on really hot days, a fan can flip from saviour to sauna—more convection oven than a breath of fresh air. So where is that threshold? Public health bodies have advised that older people—who sweat less, and are more vulnerable to heat—shouldn’t rely on fans when it’s hotter than 35 degrees Celsius. Modelling by one group of scientists suggests the limit is 33 degrees, while another model spat out 38 degrees—a pretty significant divergence. Fergus O’Connor, an Australian environmental physiologist at Queensland’s Griffith University, and his colleagues decided to test this question in the lab. They convinced 18 people aged between 65 and 85 to swelter in a 36-degree room for eight hours under three conditions—no fan, a fan on low, and a fan on high. The fan was placed a metre away, blowing directly on their skin (too ruffly to read a newspaper or magazine, but the volunteers were allowed Netflix and e-readers). During all of the tests, the subjects’ body temperatures spiked to a mean of 38.3 degrees. “The fan had no benefit whatsoever,” says O’Connor—though it didn’t make things worse, either. Under the highest setting, blowing at four metres per second, subjects reported feeling slightly cooler, but their body heated up regardless. O’Connor’s team haven’t yet tested the fans under other temperatures. But he advises that when the mercury rises past 33 degrees or so, you’re better to find an air-conditioned public space—perhaps your local library—rather than rely on a fan.
Lead is highly toxic—but to kea, the metal tastes like a sweet treat. So for years, the native parrots have been dying of lead poisoning: enduring vomiting, seizures, cognitive decline, and starving. Because kea are often seen chewing on lead nails, flashing and paint from backcountry huts and other buildings, there’s been a recent nationwide effort to remove these materials and replace them with non-toxic alternatives. At the same time, though, hunters and cullers—including those from the Department of Conservation (DOC)—are carpeting the backcountry with lead bullets. Of course, lead served up in an animal carcass is even more tempting for our scavenging native birds. Luckily, lead has a different isotopic makeup depending on where it was mined—which means we can figure out what’s really poisoning kea. The bullets are making kea sick, confirms a study published in October, in the journal Conservation Letters. Scientists from New Zealand, Australia, and the US, in collaboration with Ngāi Tahu and DOC, analysed 91 blood samples from wild kea. Of 69 birds that met the threshold for lead exposure, their blood indicated that one-third were eating ammunition, one-third had been ripping into buildings, and the final third were doing both. In California, when scientists found dozens of condors were dying because of lead shot in carcasses, the state outlawed lead ammunition. Condor populations are now recovering. Here, kea numbers are estimated to have fallen between 50 and 80 per cent over the past four decades. Eliminating lead poisoning could be the difference between the birds’ extinction and survival, says study co-author Eric Buenz, from the Nelson Marlborough Institute of Technology and the Mayo Clinic in the US. “It’s something that is so easy to change, because this is the only source of lead that’s now being deposited into the environment.” The scientists are urging DOC to phase out lead ammunition entirely and use copper instead. In a statement, DOC says that because of concerns over kea, it has already stopped using lead bullets to cull tahr. It does still use lead ammunition to control deer and goats in kea habitat. “Unfortunately, lead-free ammunition can be more expensive, less available, less effective and require more stringent operational safety precautions than lead-based ammunition.” Any further change might hamper culling, DOC says—in which case, sticking with lead could work out better for kea and other native species overall. (An evaluation of this strategy is due next year.) Hunters will need to be convinced, too. But Buenz, a keen hunter himself, says copper bullets cost only slightly more, are just as effective, and come with the added bonus of making wild meat safer for human consumption.
A mycologist on a mission to catalogue all New Zealand’s species of rust has just added another 26 to the list. For Eric McKenzie, the fungal pathogens have been a 55-year passion. Some specimens have been sitting dried and unnamed in Manaaki Whenua—Landcare Research’s fungal collection for decades, but others McKenzie collected himself from shrubs and herbs in bush clearings, high-country grasslands, and islands from the Kermadecs to the subantarctics. The rusts can be quite hard to find, he says. “You’ve got to get down on your hands and knees, stick your bum in the air and crawl around. And then I have to get up again afterwards!” His efforts are rewarded, though, when he sees their bright colours and unique shapes under the microscope—such as Coleosporium puawhananga, pictured here on clematis. “It’s the thrill of the chase,” he says. “You never know quite what you’re going to see.” One of McKenzie’s new rusts, described in New Zealand Journal of Botany, is an exotic that favours fuchsia plants. The other 25 are natives, and go for hosts including karo and the Marlborough rock daisy. Typically, each rust infects a specific species or genus, forming clumps of orange, yellow or brown spores on leaves and stems. Spread on the wind or by passing animals (or people), rust infections can take out whole crops—the ancient Romans had a god of rust, Robigus, and every year sacrificed a puppy to him in the hope of alleviating the damage done by wheat rust. The notorious invader myrtle rust now tearing through New Zealand bush is a particular threat, because unusually, it attacks a wide range of plants, and hits them hard (see ‘The Forgotten Pandemic,’ Issue 188). We now know of around 150 native rusts—but unlike myrtle rust, they cause only minor damage, says McKenzie, as they “all live pretty much in harmony and balance with their host plant”.
Off the warming northeastern coasts of New Zealand, a spiky problem is snowballing. Centrostephanus rodgersii, the longspined sea urchin, is a native species, but the comparatively balmy winters underwater are supercharging its reproduction. On top of that, we’ve eaten too many of its probable key predators—big crays. Throngs of these deep-purple urchins can, like kina, demolish kelp forests and create bare underwater barrens—only worse, says the University of Auckland’s Arie Spyksma (who also works with New Zealand Geographic). While kina bottom out around 15 metres below sea level, Centrostephanus thrive from five metres to 50. “That’s catastrophic,” says Spyksma. “Kelp forests, those deep invertebrate communities, they’re all at risk of just being wiped out. But before we can really manage them, we need to understand the scale of the problem. Where are they occurring? Where are the hotspots?” Enter the robots. Spyksma and collaborators from Tasmania—where Centrostephanus is predicted to demolish 50 per cent of kelp forests within six years if large-scale control doesn’t happen—are enlisting artificial intelligence to speed up the science and keep pace with rapidly changing ocean ecosystems. The scientists have developed an “urchinbot”, which can rapidly analyse vast numbers of underwater images and pinpoint sea urchins, labelling each as kina or Centrostephanus (pictured is a scan of the seafloor at Tūhua/Mayor Island). The tech is right about 90 per cent of the time, says Spyksma—a “really good” hit rate that lifts a huge processing load from scientists. They’ve also created another AI tool to classify seafloor habitat, identifying whether it’s kelp forest or urchin barren. Researchers still have to go out and collect the images at sea—they can do this fairly quickly, by towing cameras from a boat or remotely operated vehicle. But then the robots will go to work. In Tasmania, they’ll track how well management operations work. In New Zealand, they’ll show us where the urchins have taken hold. Both robots will soon be available to hapū and community groups, pumping out the information we need to plan the best pushback—and protect our precious kelp forests.
How the animal kingdom first grew feathers—and got off the ground.
Ray Blackburn and Maggie Cornish have volunteered at the Tāwharanui Open Sanctuary north of Auckland since they retired 15 years ago. They kill rats, collect seeds, plant trees. The work gets them outside, keeps them physically and mentally fit—and has become a big part of their social life, leading to dinners, parties, camping and birding trips outside of the project. “You’re working together, chatting away about your life and your family. You really can’t help but adopt these people, or be adopted,” says Blackburn. Volunteers keep coming back, Cornish says, because they enjoy each other’s company, and feel valued and respected. Massey University researchers found exactly that in a new study based on interviews and surveys of more than 100 conservation volunteers in Manawatū. The researchers investigated what makes such volunteers commit for the long haul, and found that adequate time for socialising was a key motivating factor. So was the desire to make a meaningful contribution to the environment and their local community. “I could achieve the same thing by playing golf or bowls,” says Blackburn, “but when you finally fall off the perch, what use is your golf handicap to the rest of the world?”
Bees and cockatoos, walruses, spider monkeys, pūkeko—throughout the animal kingdom, individuals often favour a certain hand (or eye, or antenna). But how did so many humans end up right-handed? And why, historically, did we give lefties the side-eye?
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