The harlequin gecko does many things that seem high risk. It stays stock still whenever it’s cold. It lives in extreme slow motion. Somehow, it’s managed to survive on predator-ridden Rakiura/Stewart Island, but can it weather our plans for its stormy home?
The enviable upsides of having something sticking out of your backside.
If it’s a dog-eat-dog world, and if nature is red in tooth and claw, why are so many animals nice to each other—and us?
Craig Mckenzie was surprised that New Zealand Geographic didn’t pick this photograph as part of our 2017 feature on kākāriki karaka, orange-fronted parakeets (‘Last Chance to See’, Issue 147). The frame, shot in beech forest near a feeder for the endangered birds, was one of his favourites. Something of a redemption, then, that it just won big in a competition run by Tūhura Otago Museum. McKenzie won the overall People’s Choice award, up against all the people’s choice winners from the past 25 years. Caw!
To design sleeker, sneakier aircraft, researchers are mimicking the physics of our feathered friends. Pigeonbot II is a robot garbed in genuine bird plumage. Fifty-two feathers are attached to a mechanical wing with joints akin to wrist and finger. Programmed to imitate the reflexes of a bird in flight, Pigeonbot adjusts its wings, spreads its tailfeathers, tilts and shifts just like the real thing. These manoeuvres help the robot stay steady, whether gliding in a turbulent wind tunnel or soaring outdoors. In aircraft, it’s the vertical tailfin that confers this stability. Losing the fin and emulating avian aerodynamics, the Stanford University team behind the bot conclude, would make aircraft more energy efficient. It would also help the plane evade radar. More innovation comes from birds of prey: a hawk-drone built by a Swiss team can twist its tail to bank left or right, or even turn sharply at high speed, while keeping its wings still (see page 34 for more on hawks). Another recent study, out of Princeton University, finds that wing flaps inspired by covert feathers—the smaller plumes that create a smooth contour on top of the wing—can boost lift, reduce drag, and enhance stability. It’s not just feathers, either. A second Swiss robot, dubbed RAVEN, has birdlike legs that allow it to leap into flight faster and more efficiently than a standing take-off.
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.
Get out of the city this summer and you’re bound to glimpse a kāhu. The powerful, clever native hawks are revered by those who come to know them. And yet we’ve been slaughtering them for a century and a half. Why?
They’ve been here 300 million years. They grow on rock, or in deserts, or underwater, or on dead animals—and they can survive for centuries. In short, mosses are super cool.
Last week, scientists and kaitiaki set to work to necropsy the rarest whale ever discovered—a spade-toothed beaked whale that washed up at the mouth of the Taieri River, south of Dunedin.
Buff-tailed bumblebees, important pollinators in Aotearoa, have a taste for flowers with bigger “bullseye” markings at the centre, a study published in Science Advances indicates. UK scientists 3D-printed targets to mimic three species of hibiscus, and laced them with sugar water. They found the bees went for the bigger option—even when only the smaller target had the “nectar” reward—and sped up as they zipped between these more dramatically painted flowers. That’s good for the bees: a quick commute is safer for them, as they run out of energy fast. It’s also good for the flowers that were the focus of their attentions, including Hibiscus trionum, an exotic which is widespread here and has a decent-sized bullseye. But it’s bad news for our very rare native Hibiscus richardsonii, pictured here, which was also part of the study—and, with its modest central splotch, often ignored by the pollinators.
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.
What to do when giant eagles are hunting you? Change colour, if you’re a kākāpō. Researchers now think the reason kākāpō come in two hues—green or olive—is that once, they had to dodge flying apex predators such as the Haast’s eagle and kērangi, Eyles’ harrier. Department of Conservation kākāpō specialist Andrew Digby says all kākāpō were once green. But a new study he co-authored shows that about half a million years after giant eagles arrived on the scene, “olive became the new kid on the block”. That novelty kept the olive birds safer. “Birds of prey hunt by sight,” he says. “If you’re used to seeing green, you might not recognise olive as food.” The research, published in PLOS Biology, drew on extensive genome sequencing of nearly all living kākāpō. The findings suggest the rarer colour at any point was harder for predators to spot. That advantage meant the dominant shade swung back and forth, showing up today as an even split. “It’s really unusual. Usually one would become dominant, and the other would drift away,” says Digby. Even more unusually, it seems a single gene controls the colour switch. “I got a really, really strong signal,” says Lara Urban, a research fellow at the University of Otago, who decoded the genetic explanation. “Strong enough to accurately predict the future colour of a fluffy white chick, based on parent genomics alone. It was almost too good to be true.” The value of the work, she says, is considering whether the green-olive divide still serves a purpose in a tightly managed population of just 244 birds—with no huge birds of prey in play. “The beauty is that we can now ask if it’s important to keep both colours,” says Urban. “When we’re trying to expand the population and bring kākāpō back to the mainlaind, is there a fitness advantage?” The short answer, she says, is no. Colour differences in kākāpō are “ghosts of selection past” and one less thing for conservationists to worry about maintaining.
If the South Island kōkako is not extinct—if, as many believe, a handful of the birds are still alive in the forests of the West Coast—they’re doing a very good job of staying hidden. There hasn’t been an accepted sighting since 2007. But in the mechatronics lab of the University of Canterbury, a remarkable new search tool is taking shape. Five fourth-year engineering students have spent all year working on a robot bird that looks, moves and sounds like the real thing. “It’s got the head movement, the tail flapping, the wing flutters,” says team member Eve Hudson. “Obviously it doesn’t fly, but luckily the bird sticks to the forest floor so it shouldn’t be too much of an issue.” The model is bait. It will be installed in a likely patch of West Coast bush by the South Island Kōkako Charitable Trust, and broadcast eerie songs—recordings of its North Island cousins. If a kōkako is in the area, the hope is that it will swoop in for a closer look and be picked up on audio and video recorders. “Anything’s possible,” says Hudson, firmly. Other models have been deployed in the decades-long search for the kōkako, but nothing like this. Crucially, this bird’s movements are interlinked, meaning it can make more than one twitch or pitch at a time. When it leans forward, says Hudson, its wings give a tiny flutter. And the head has three degrees of freedom: it can lift up and out and twist, while the beak lowers. Picture a snake pulling back to strike—or a real kōkako, cocking its head. 3D printing, says Hudson, has been a godsend. The team printed the legs, head and body using measurements provided by a Swedish university, which happened to have scanned a taxidermied specimen. The last stage was low-tech. The team dyed magpie feathers, then fixed them to the model with hot glue, using possum fur for the finer plumage around the head. Will the bird cope with a fortnight in the West Coast bush? Hudson points out it’s not just the humidity and rain it must endure, but marauding insects, and perhaps the odd possum trying its luck. A box that connects to the model and houses the battery and other components is 3D-printed plastic. Most of the bird itself is steel, and its exterior is coated in latex. Still, the idea of leaving their creation in the bush for two weeks makes the team slightly nervous. “It’s kind of like our baby,” Hudson says. “We’ve all become absolute bird fanatics over it.”
For decades, New Zealand has been insulated from highly pathogenic avian flu—the disease that has devastated poultry flocks and waterfowl around the world. But now, the virus has evolved to take down mammals and seabirds, and that dramatically raises the chances of it reaching us. For some of our native species, this virus could be the greatest threat since the arrival of humans. Are we ready for it?
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”.
Climate change will help one of the most pernicious pest birds in the country spread south, a new study has found—and reports from Christchurch suggest it’s already happening. Common mynas, native to India, were introduced to New Zealand in the late 1800s in an attempt to control agricultural pests. Introductions in the South Island mostly failed, but the bolshie birds became well established in the upper North Island. Now, the mynas are themselves agricultural pests. The birds are also fiercely territorial and destroy the eggs of other species, including natives. In a paper published in the journal Biological Invasions, University of Auckland PhD student Kamolphat Atsawawaranunt looks at ecological variables such as rainfall, season length and tree cover to unpick how much mynas had to adapt to thrive here, and where they might be able to live as the weather warms. [caption id="attachment_513998" align="alignnone" width="954"] Green is go—for mynas, that is. Right now the South Island is mostly too cold for the pests. This map shows where the birds may be able to live based on a temperature rise of 2.4 °C by 2085 and increased human population density projections.[/caption] He maps three future scenarios, according to a range of climate pathways—and in all of them, the mynas spread south. Birdwatchers in Christchurch report the southern invasion is already under way. Ornithologist Peter Langlands has been keeping an eye on a number of birds in the city—he suspects these mynas are either unwanted pets or hitchhiked in on container ships. “It’s probably just by accident that they haven’t already spread down here in greater numbers,” he says. “There’s really nothing stopping them from taking off, especially with the winters being milder.” He’s nicknamed the first one he spotted “Houdini”. The Canterbury Regional Council has engaged a contractor to cull the mynas it is aware of, and Langlands has set up a Facebook page to collate sightings.
Crayfish are the great creators and cleanup crew of their freshwater homes. They burrow into banks, unstick gummy sediment, and deal with anything that ends up dead in the water. Plus, they’re delicious. Hundreds of years ago Māori spread these tasty all-rounders from place to place. Can doing the same now help save the species?
Most snail shells have a spiral only on the right—the left is more of a “behind-the-scenes business end”, as illustrator Giselle Clarkson puts it. Picture the bottom of a bread roll, or an outfit that looks great from the front—but at the back, it’s nipped and tucked with safety pins. “The back of the snail is like that, where everything is kind of cinched into place to make the front look amazing.” In picture books, movement usually travels from left to right across the page. This means the less-fancy side of snails has largely been wiped from the canon. But Clarkson snuck a snail “butt” into her 2021 book The Tiny Woman’s Coat—and we decided to show you one that didn’t quite make it into her ‘Just So’ cartoons on handedness and chirality. Our apologies to the snail, who is slightly mortified to be showing you his not-so-swish side.
Asia Martusia King’s first piece for this magazine is a History column about bears going stir crazy in New Zealand zoos. The Wellington science communicator is training as a zookeeper, a dream job that grew from a childhood spent chasing bugs in the garden and, later, “a fierce Pokémon obsession”. Sounds silly, she says, but she was surprised by how big giraffes are. “As a visitor, you’re usually viewing them from a platform. It’s so different gawking up at this six-metre-tall alien creature you’re feeding, with giraffe drool and beetroot pulp dribbling down your shirt. Their poo is surprisingly tiny, though.”
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