Read more
Geo News

Sunfish have pretty sweet moves, actually

To an orca, a sunfish is a bit like a watermelon: a nutritious, watery snack, but hard to swallow whole. Also like watermelons, sunfish (also called mola) don’t bite back. This makes them the ideal “training prey” for juvenile orcas, according to New Zealand orca scientist Ingrid Visser. In the first-ever review of orca-sunfish interactions, Visser, along with sunfish researcher Marianne Nyegaard and orca researcher London Fletcher, found several instances of juvenile-parent orca pairs hunting sunfish. About 40 per cent of the dozens of photos, videos and oral accounts they analysed didn’t appear to be about predation, but simply entertainment. Orcas flung sunfish like frisbees, pushed them around underwater, and balanced them on noses in what Visser calls a “mola moustache”. The researchers also found records of orcas extracting a meal of intestinal spaghetti: “It’s like they’ve got a string of sausages in their mouth, pulling them out of the sunfish, which is often still alive and swimming around,” says Visser. “They split the sunfish up like a taco or a pita bread… stick their faces in, and eat the insides out.” One underwater video filmed in New Zealand reveals that sunfish are quick on their fins despite their dinnerplate anatomy. “We thought the orca were pushing the sunfish upside down,” says Nyegaard, “but the mola was thrashing and spinning in crazy manoeuvres all by itself. I thought, ‘What the hell is it doing?!’” The sunfish was attempting to evade the orca by using a suite of sneaky moves, including spinning rapidly, breaching, flipping upside down, or positioning itself with its rigid backside towards the orca’s mouth. “People thought sunfish were just great big blobs and that mola design was cumbersome, but this adds further proof that they’re actually quite good at swimming,” says Visser. “They can breach, their cruise and boost speeds are impressive, and this is more recognition of their agility.”
Read more
Geo News

Kiekie, ambrosia of the bush

Kiekie belongs to the widely dispersed pandanus family, well known as a source of weaving material throughout the Pacific. It’s the only member of the family native to Aotearoa, and it’s best known for its deep green, glossy leaves—but it also produces fruit regarded by many as the finest delicacy of our native bush. The taste sensation of its fruit sent early settlers grasping for superlatives; they made comparisons to pineapple; ripe pears with an aroma resembling vanilla; and soft, waxy bananas. On the female plant, the fruit ripens in late autumn or early winter. Stalks produce three to five fruit (ureure) that look like a cross between sweetcorn and pineapple. The rough skin is peeled away to reveal a sweet pulp of berries inside. The male flower produces a creamy, beige stamen mounted on a sweet, fleshy base of leaves (bracts) known as tāwhara. It flowers for about a fortnight in October. Traditionally, the bracts were eaten fresh off the plant; it was always a race to beat bush rats (and, more recently, possums) to this seasonal treat. Some settlers described a cooling jelly drink made from the juice of tāwhara; others made a jelly from the flowers that apparently tasted like preserved strawberries. Kiekie is common in the undergrowth of lowland forest, its aerial roots locking into bark and rock crevices for grip as it climbs up into the canopy. Its elastic roots were collected and used extensively as lashings and for making sails on canoes. It was also used to bind together tāruke (crayfish pots) and hīnaki (eel pots). For Māori weavers, kiekie was second in importance only to harakeke (flax). Its leaves are narrower and shorter, but may be more durable under water. Strips are split from kiekie leaves, scraped, boiled, rinsed and dried in the sun to bleach. The fibre was often used for the finest whāriki (mats) and kete whakairo (woven bags) and to create tukutuku (wall panels). It was also used for rain-capes, belts and hats. In Traditional Lifeways of the Southern Maori, Herries Beattie recorded a story of the mythological origins of kiekie in Te Waipounamu. Legend has it that a character by the name of Tamatakuariki travelled down the Poutini coast in search of his wife and, in his haste, shreds of his pōkeka (rain cape) were torn off by the vegetation. These fell to the ground and germinated as kiekie. One name of the plant is therefore Te Pōkeka-a-Tama, Tama’s raincoat.
Read more
Features

The future of the world is written in penguin blood

Erect-crested penguins are one of the most mysterious birds on the planet. We have little idea how many there are, what they eat, where they forage, or how their environment may be changing as the Southern Ocean warms. No one has even visited the Bounty Islands where they breed in three years. Scientist Thomas Mattern chartered a yacht and mounted a mission to answer some of these urgent questions before it’s too late.
Read more
Features

For the love of velvet worms

This creature is so old it defies imagination. Its genome is far more complex than ours—big enough to crash one of the country’s most powerful supercomputers. Will we lose the species before we glimpse the ancient stories it has to tell?
Read more
Geo News

Tying the forest together

This is one plant you won’t find in a glossy coffee-table book on the 100 prettiest native species for the garden. Supplejack is a climber that inhabits the deep, dark, shadowy gullies of our native bush. In Māori legend, supplejack is said to have sprouted from the bloody tip of the tail of the taniwha Tunaroa, whom Māui hacked to pieces and tossed far and wide into the bush for molesting his wife Raukura. Supplejack vines grow from a bulb the size of a man’s fist, their long glossy black strands about the thickness of a finger, with a knuckle at each node like bamboo. The vine wraps itself around the limbs of saplings and forest giants alike, sometimes even dragging them to the forest floor. Like many aka (vines), supplejack is regarded as a nuisance: an impenetrable tangle that strangles the life out of regenerating bush and stops trampers in their tracks. Little wonder it was known as “taihoa” or “wait-a-while” by Pākehā bushmen. But supplejack had an extraordinary range of uses. The vine’s leaves, young shoots and roots were made into medicinal tonics to treat everything from sore throats to chronic rheumatism, recorded Murdoch Riley in Māori Healing and Herbal. Pākehā and Māori used supplejack laced between a couple of saplings to make a stretcher to carry the wounded out of the bush, or to create a bed sprung with a latticework of vines. A bundle of tightly bound vines made a good torch. Set alight, the vines could also be used to cauterise wounds. Cut into slivers and boiled to extract the juice, the vines could produce a “wonderful beer; clear, gold and heady”, according to Riley. Boys built bows from supplejack. Schoolmasters used supplejack canes to discipline lads who misbehaved. In 1906, ethnographer Elsdon Best noted hoops of supplejack poked into the ground and lashed together to support the weight of a young child learning to walk. Supplejack was used to make all sorts of ingenious fishing devices, traps, nets and scoops. Stiff, springy hoops of vine were used to hold open the mouths of scoop nets or to strengthen and reinforce fish traps, hīnaki (eel nets) and bag nets. Many Ngāi Tahu whānau still remember cutting supplejack vines from the bush and building tāruke (crayfish pots) in the mid-1900s. In latter years, the designers improvised with hybrid designs, lacing supplejack hoops together with No. 8 wire. They weighted their pots with concrete or scrap iron donated by New Zealand Railways. Tāruke had significant advantages over the steel-framed, wire-netting-clad pots that eventually replaced them; they didn’t rust and were durable and flexible enough to withstand perhaps a decade of the worst storms Tangaroa could throw at them. Excerpted from Treasures of Tāne: Plants of Ngāi Tahu by Rob Tipa (Huia Press).
Read more
Geo News

Step away from the kākāpō

The 2019 kākāpō breeding season was the best in the 26-year history of the recovery programme. But it was also the worst: the fungal disease aspergillosis hit the Codfish Island/Whenua Hou sanctuary, infecting 21 kākāpō and killing nine—all either nesting females, chicks or juveniles. New fungal genome analysis shows the birds all caught the same strain—and it probably came in with people, most likely on supplementary food. That is surprising, says University of Otago geneticist Peter Dearden, but “we can’t explain it unless it’s been carried by humans”. The same strain of aspergillosis was also identified on Anchor Island in Fiordland, home to a smaller kākāpō breeding population. But the birds there didn’t get sick. [caption id="attachment_472574" align="alignnone" width="600"] Kākāpō Huhū’s results show the shadow of the fungus, though the bird survived.[/caption] Other factors such as climate change are likely in play. “It was a very hot, dry summer in 2019,” says Andrew Digby, the science adviser for DOC’s recovery programme, who was involved in the research. “All the infections occurred over quite a narrow time period, and it might be that the climatic conditions were [right on Whenua Hou] at the same time as chicks were at their most vulnerable stage.” All islands where kākāpō breed are subject to strict quarantine and hygiene procedures, but the team have now put in additional measures such as freezing supplementary food, ventilating nests and not moving chicks directly between them. They rely more on remote monitoring and have established hands-off breeding sites on Te Kākahu-o-Tamatea/Chalky Island in Fiordland. “That’s how we want to be managing kākāpō in the future,” Digby says. “It’s not to say the intense management is wrong. Without it, kākāpō would be virtually extinct by now. But it’s another reason why it’s important that we step back.”
Read more
Geo News

State of cray

The crayfish population in the Hauraki Gulf is in worse shape than official fishery stock assessments suggest, according to a new analysis. Researchers from the University of Auckland used two marine reserves— Cape Rodney-Okakari Point (Goat Island) and Tāwharanui—as “proxies” for natural, unfished crayfish abundance. “We hired a fisherman and all of his gear and we did cray potting inside and outside the marine reserve for two years,” says Benn Hanns, lead author of the paper. Comparing catch rates inside and outside the marine reserves indicates that the crayfish population has plummeted to around two to three per cent of unfished levels—though Hanns suggests the population may be even lower. It’s substantially different from the Ministry for Primary Industries’ estimate of 18 per cent. Under current rules, if a fishery drops below 10 per cent of its original, unfished level, it must be closed. Stock assessments rely heavily on fisheries-dependent data and models with complex, inbuilt assumptions. Hanns says some of these assumptions are outdated. “This research shows the utility of marine reserves beyond conservation… They can actually be these really important sanity-checking tools.” But even within the marine reserves, numbers of crayfish have been declining in recent years. Hanns chalks this up to one big problem: the marine reserves are too small. His research has contributed to a recent proposal to expand Goat Island Marine Reserve, currently under consideration.
Read more
Features

The great bird nerds

Around the country, Birds New Zealand branches are trying to motivate their members to fill in one more observation list, while keen birders are ticking off grid squares, aiming for high scores. They’re working on the Bird Atlas, the biggest-ever citizen-science project on our shores.

Read more
Geo News

Colourful catch-22

Nearly 500 songbird species have been flagged as targets for wildlife poachers thanks to their unique plumage. Among them are three New Zealand species: the popokōtea/whitehead, mohua/yellowhead, and kōkako. Like their parrot cousins, songbirds garbed in eye-catching colour palettes attract more human admiration. But bright colouration is a double-edged sword: it also makes birds highly sought after in the pet trade. In turn, this means that populations dwindle as poachers snaffle birds from the wild—a fate that currently befalls around 30 per cent of songbirds, especially in the tropics. Colourful birds in the “perching bird” (passerine) family are more likely to be both traded and threatened with extinction, according to a new analysis. Surprisingly, white is a popular hue in captive birds—exemplified by the Bali myna, which tops off its snowy plumage with a crisp black tail-tip and zingy blue eye-liner. The myna is critically endangered due to poaching for the caged-bird market. As populations of desired species decline, poachers shift their efforts to birds with similar qualities. “Most of New Zealand’s birds are not too colourful—although the hihi and kōtare offer obvious exceptions,” says study co-author James Dale from Massey University. Nonetheless, New Zealand is pinpointed as a place that could see a drop in both colour diversity and uniqueness among birds. Without conservation efforts and proactive trading regulations, the future for our feathered friends could be decidedly drab.
Read more
Geo News

Mussel building

One day in 2008, marine science student Kura Paul-Burke was diving in Ōhiwa’s murky waters when the grey-brown of the sea floor suddenly gave way to a brilliant orange. At first, she was struck by the beauty of it. Then she realised she was looking at hundreds of thousands of 11-armed sea stars—pātangaroa, a native species—stacked five or six layers deep. Behind them, the seabed was littered with empty green-lipped mussel shells. In 2007, the Bay of Plenty harbour was home to an estimated 112 million mussels. By 2019, only 78,000 were left. Paul-Burke’s Ngāti Awa elders had noticed signs of decline well before then. No-one knew why the mussels were dying. Was it overharvesting? Sedimentation? But they knew there used to be more mussel beds, and in 2006, they urged her to investigate—then helped her to map the old mussel beds using both traditional landmarks and scuba surveys. Researchers are still confirming the starfish are to blame, and figuring out what is causing the ecosystem imbalance in the harbour. In the meantime, Paul-Burke—now a professor of mātai moana (marine research) at the University of Waikato—wanted to see if it was possible to save the mussels and the harbour. The project wove together four iwi (Ngāti Awa, Te Ūpokorehe, Te Whakatōhea and Waimana Kaakū [Tūhoe]) and three councils, kaumātua and young people (pictured below, L-R: Megan Ranapia, Te Waikamihi Lambert and Cameron Phillips), mātauranga Māori and marine science. Together, they built four restoration stations where baby mussel spat could attach and grow. Instead of using commercial plastic spat lines, they experimented with natural fibres. The strongest were made from fallen tī kōuka leaves woven into rope by master weaver Rokahurihia Ngarimu-Cameron and her students. In late 2018, the team hung them on floats in midwater, out of the reach of clambering starfish. It worked. Mussels began growing in such numbers that they dragged the floats under the surface. When the tī kōuka lines eventually degraded, young mussels fell to the bottom “as a whānau”, Paul-Burke says, before reattaching to the sea floor. As the researchers describe in a new paper, by 2021, three new mussel beds had formed close to the restoration stations, and the mussel population had increased ten-fold—showing what can be accomplished, says Paul-Burke, when several knowledge streams and communities pull together.

Read more
Books

Secrets of the Sea: The story of New Zealand’s native sea creatures

On the surface, this is a straightforward book of fish facts. On another level, it’s a story about gorging and slurping, about human nature, about waste, about greed. There’s a bit near the end about how the hagfish (or “bloody snot eel”, as Dad would call it) will patiently rasp itself inside softening corpses on the seafloor. If that doesn’t work, the hagfish will force its body against the rotting ribcage, or belly, or whatever, writhing until it gives way. Gross, but not as gross as the human appetite. The reading experience reminded me of being a kid and watching, horrified, as my uncle ate a whole bucket of prawns. Robert Vennell fillets his beautiful book into five sections, from fresh water and shorelines to the deep seas. Within each he covers just a handful of creatures. Bold choice, quality over quantity—and undoubtedly the best one. Each chapter is deep and rich. Māori perspectives, stories and histories are centred. Taxonomy and etymology, aptly, are broken out into little boxes. Vivid illustrations (some of which are reproduced here) flicker and dart throughout. Vennell is very good at writing about abundance. He conjures an Aotearoa where dogs lap up whitebait from rivers; the piper fish swim in shoals three kilometres long; kids walking home from school stop off at the rockpools, picking up a crayfish for each family member. His language is plain: eels are “gigantic tubes of meat”; pāua “thick, meaty chunks of protein”. But the numbers are obscene. Twenty thousand eels served at a feast in 1838. Eighteen million crayfish tails shipped to the US in 1949 (the tails were often snapped off, the crays dumped at sea). One weekend, 50,000 people turned up at a beach near Dargaville to dig for toheroa. They took home more than a million shellfish, leaving what they couldn’t eat at the tip. There are small numbers, equally grotesque: Vennell writes of a Dunedin hotel serving up flounder less than five centimetres long, and of blue cod for sale, weighing less than 100 grams. There’s a chapter about upokororo, the New Zealand grayling, last seen in 1923. Māori had stealthy methods of catching these particularly skittish fish. Pākehā simply dynamited the rivers, “causing entire shoals to float to the surface, where they could be scooped up and collected”. How on Earth have we managed to drive only one fish extinct? The true secret of the sea is that we ate it all.

Read more
Geo News

Clicky cliques

Sperm whales are tribal creatures—and they avoid interacting with those from other clans, even when they share the same waters. But how do they identify each other?
Read more
Geo News

Cats are unpredictable. Who knew?

Finding patterns in cat behaviour would help us to stop feral cats from chewing their way through native bat roosts and bird life. And so a group of New Zealand researchers pored over 36 studies from around the world in an attempt to understand the size of feral cats’ home range—where they hunt, mate, and nurse their young. “Are there similarities between cats?” they asked. Surprising nobody, the answer is no. The study, published in the New Zealand Journal of Ecology, found no discernible patterns to the cats’ behaviour, even when taking into account the effects of season, habitat type, cat size, and competitor animals. One male cat roamed 3232 hectares, its home range the area of Gisborne. The most adventurous female cat roamed 2078 hectares; another stayed within 10 hectares. As any cat owner might tell you, every feline has a different idea of home.

Read more
Geo News

How did penguins get so great?

Penguins traded in their wings for flippers more than 60 million years ago, long before there were icesheets in Antarctica. But aeons of evolution turned them into supremely adapted marine hunters, capable of diving deep and withstanding extreme cold.

Read more
Features

Killer algae

The invasive seaweed Caulerpa brachypus was discovered in New Zealand just over a year ago, and it promises to ruin everything. On Aotea/Great Barrier Island, people are sacrificing their way of life in an attempt to contain the weed—and stop it reaching the mainland.

Loading..

3 FREE ARTICLES LEFT

Subscribe for $1  | 

3 FREE ARTICLES LEFT THIS MONTH

Keep reading for just $1

$1 trial for two weeks, thereafter $8.50 every two months, cancel any time

Already a subscriber?

Signed in as . Sign out

SEE THE OPTIONS

{{ contentNotIncluded('company') }} has not subscribed to {{ contentNotIncluded('contentType') }}.

Ask your librarian to subscribe to this service next year. Alternatively, use a home network and buy a digital subscription—just $1/week...

Go back

×

Subscribe to our free newsletter for news and prizes