Troubled lives of the A-listers
The birds we love most are also the most at risk.
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Between ice and fire
On a summer afternoon in early 2020, the land of the long white cloud temporarily became a land shrouded in an orange haze. Catastrophic bushfires in Australia produced a huge plume of smoke that drifted across the Tasman, reaching altitudes as high as 16 kilometres before settling over the Southern Ocean. Tiny motes of ash and dust mixed with gases fertilised an area of sea larger than Australia itself, seeding an extraordinary bloom of microscopic algae, also known as phytoplankton. The sprinkling of smoke provided three times more iron than usual, promoting unprecedented growth for the time of year. When algae grow, they photosynthesise like a plant. They use sunlight to power the conversion of water and carbon dioxide into food. The smoke-fuelled bloom of early 2020 sponged up a lot of carbon dioxide from the atmosphere, roughly equivalent to the amount released by the bushfires. However, it’s unknown whether this carbon removal has a lasting effect. Further south, in the seas around Antarctica, the bloom-and-bust cycles of phytoplankton are usually driven by ice, not fire. When sea ice breaks up and melts, it creates favourable conditions for algal blooms. But when sea-ice cover remains, the lack of sunlight means algae don’t flourish. These blooms play a dual role: as a carbon sink, drawing carbon dioxide from the atmosphere into the deep ocean, and as the basis of the Antarctic food web. As the changing climate shifts sea ice around the Antarctic coast, there will be flow-on effects for phytoplankton blooms. In turn, these effects will have implications for the wider Antarctic ecosystem and the global carbon cycle.
Losing tuna
Many Pacific Island nations depend on tuna for survival: the governments of Tuvalu, Tokelau and Kiribati derive more than half their national income from tuna fishing licences and access fees. But climate change will eventually drive the lucrative tuna populations east, away from the territorial waters of many island states and out into the high seas, according to new modelling published in Nature Sustainability in July. If ocean warming continues at current rates, the study predicts, the tuna catch in the waters of ten Pacific nations is expected to decline by an average of 20 per cent by 2050. For some countries, that will result in losses of government revenue of up to 17 per cent—reducing their ability to help their communities adapt to climate change, and potentially making them more reliant on foreign aid. Tuna stocks could be affected, too, as fishing rules, designed to ensure sustainability, are much harder to enforce on the high seas.
A new seahorse
New Zealand has a brand-new endemic species: a tiny, jewel-coloured pygmy pipehorse, just a few centimetres long, that has been hiding in plain sight among the waving seaweeds of the Northland coast. “It’s very unusual for a new species of seahorse to be discovered in New Zealand,” says Auckland Museum’s head of natural sciences, Tom Trnski, who was involved in naming and describing it. “It’s so well camouflaged, and I think that’s why it’s eluded discovery for so long.” The tiny pipehorse has so far been found only off the east coast of Northland: peering shyly from the vegetation on undersea walls near the Bay of Islands, the Poor Knights Island, and Whangaruru. Its natural range pretty much corresponds with Ngātiwai’s rohe, so the scientists asked the iwi to gift a name for the species. Together, the kaumātua and the scientists came up with Cylix tupareomanaia. “Cylix”, which means “chalice” in Latin and Greek, refers to the cup-shaped formation on top of the creature’s head. “Tūpare o manaia” translates as ‘‘the garland of the seahorse”, referencing the animal’s jointed head crest and the word for seahorse in Māori: manaia. It also evokes the location where the original pipehorse specimen was collected, Home Point, which Ngātiwai call Tu Pare o Huia, the plume of the huia. In a world first, Ngātiwai is credited as the “naming authority” of the species. (Historically, this has always been scientists.) “It’s a really beautiful name that links this small taonga with Ngātiwai, the kaitiaki of the coast,” says Trnski. Trnski and his colleagues first submitted the paper to a European scientific journal, but its editors wanted them to cut the Māori abstract—written in the form of a pepeha, or introduction, for the species—and refused to give the naming credit to Ngātiwai. The scientists withdrew the paper and found a new home for it at another journal, where it appeared in full, as weaving of indigenous knowledge with science was respected.
Seal census
The population of Weddell seals in Antarctica is smaller than expected, according to a new crowdsourced count of the iconic polar species. Around 202,000 female Weddell seals call the icy coasts of Antarctica home, the study estimates—far fewer than the previous estimate of 800,000. “That doesn’t necessarily mean there has been a big decrease of Weddell seals recently,” says lead researcher Michelle LaRue from the University of Canterbury, “but instead, this is probably a more accurate count that we can use as a baseline to determine change over time.” More than 330,000 citizen-science volunteers tagged thousands of seals in hundreds of satellite images depicting the Antarctic coastline. The very-high-resolution (VHR) satellite images were captured in November 2011. The non-invasive approach is perfect for seal monitoring: previously “the only way to study the seals was to travel by snow machine, or if you were lucky, a helicopter flight to get a little farther afield”, says LaRue. “Now, anyone with internet access can count them from space.” It’s the first time ever that the global population of a wide-ranging animal has been estimated from direct counts. But why only count the females? During the summer months, when the images were captured, male Weddell seals spend most of their time defending their underwater territory. Meanwhile, females lounge on the ice nursing their single newborn pup, meaning the blubbery, bodacious females are the ones snapped from space (the pups are too small to appear in the images). The study also assessed where Weddell seals like to live, finding that they prefer fast ice (anchored to the shore) that is close to deep water. The fast-ice lifestyle means that the seals need to maintain breathing holes, which they gnaw open with their teeth. They also like having emperor penguins as their neighbours—as long as there aren’t too many of the fish-gobbling waddlers, which increases competition for food.
Meet the spoonbills
They arrived here from Australia without fanfare, flying across the ditch for no reason anyone has been able to deduce. But they liked the look of the place, decided to stay, and started a family. Now, they’re one of New Zealand’s most successful bird species.
The animals next door
What’s a wildlife photographer to do when lockdown puts an end to travel?
Bruce finds a solution
A disabled kea named Bruce has come up with his own tool for preening himself. Researchers gathered multiple lines of evidence to show the bird was selecting pebbles for use as a tool for self-care—the first time this has ever been observed in a parrot. Bruce was found as a young kea in Arthur’s Pass with the upper half of his beak missing—probably due to an encounter with a pest trap. He ended up at Willowbank Wildlife Reserve in Christchurch, where he learned to hold food between his tongue and lower bill, pressing it against hard objects to help him eat it. In 2019, researchers noticed he’d come up with a new innovation: a way of preening himself despite his missing beak. First, Bruce searches for the perfect stone. He rolls it around in his beak for a while to get it lined up correctly, and then he uses it to preen, grinding it against his olive-and-scarlet feathers in order to remove parasites and dust. University of Auckland researchers, including lead author Amalia Bastos, spent 20 hours over nine days camped outside Bruce’s enclosure, their eyes fixed on the parrot, in order to establish whether his tool use was deliberate or accidental. They found that 90 per cent of the time, when Bruce picked up a pebble, he used it to preen. If he happened to drop it, he retrieved it 95 per cent of the time, or found another one before continuing his routine. (They also observed the 14 other kea in the aviary for the same length of time. No other bird used pebbles while preening.) “We have a lot to learn from Bruce,” says Bastos. “He has a serious disability compared with other kea with their massive, powerful beaks, and he’s come up with this innovative way of dealing with his situation.”
Night shift
When the sun goes down, the night shift gets to work on our native plants. It’s thought New Zealand’s spectacular array of moths may be providing a hidden service after dark, transferring pollen between flowers. The problem for researchers is that studying the nocturnal behaviour of moths is extremely difficult. While it has long been known that moths visit native flowers and get pollen stuck to their hairy bodies, it has not been ascertained whether they are successfully transferring it to the female parts of neighbouring flowers. “Previously in New Zealand there’s been no good evidence of moth pollination,” says Barbara Anderson from Otago Museum. “It’s all been anecdotal and circumstantial.” “We knew they were able to remove pollen,” says Max Buxton, of Plant and Food Research, “but not whether they were moving it to the right place at the right time.” Buxton, Anderson, and Janice Lord, a University of Otago evolutionary biologist, set up an experiment in Dunedin, using moths caught in local gardens. They painted a fluorescent dye known as pollen tracker on the anthers of mānuka and pinātoro (native daphne) plants, then left the moths to it. They discovered that the moths were indeed successfully transferring pollen between flowers—the first time it has been conclusively shown moths are pollinating native plant species. Compared with other countries, New Zealand has very few bee species. Moths could be doing much of the pollination. Of New Zealand’s 2000 species of moth, 1800 are found only here, having evolved for millions of years alongside our native plants. In the face of massive habitat change and light pollution, this research, says Anderson, is just scratching the surface. “Our understanding of these interactions is at the very beginning,” she says. “Already we’re having these huge impacts on moths and their plant partners. We’re really playing catch-up.”
Candid camera
Environmental groups concerned about the amount of fish being dumped back into the sea by the fishing industry have been asking for cameras to be put on boats for years. While new regulations came into place this year requiring boats to land everything they catch, the industry has resisted the move to place cameras on those boats and those in power have continued to delay the requirement. Without cameras to ensure compliance, we are reliant on self-reported data. And as Barry Torkington, a fisheries strategist and ex-director of Leigh Fisheries says, that self-reported data is not particularly accurate. "All the delays have been red herrings," he says. "There's nothing to invent. There's nothing to test ... It's hard to find a serious fishing nation that hasn't embraced it." www.betterancestors.org
The nature of business: how the Begley family's restaurants help protect the environment
Warren Begley and his family run two restaurants in Ōtautahi Christchurch - Tutto Bene and Formaggio's - and they are also passionate environmentalists who support a range of conservation projects in the region. As Begley says, without the natural world, they would have no business, so, in his view, it is the most important stakeholder. The collaboration between the restaurants and the Ōtamahua Quail Island Ecological Restoration Project, which trust chair Ian McClellan says is a small attempt to right the wrongs of the past, is consistent with this ethos of kaitiakitanga or guardianship across time. "We have no right to operate if we can't manage our footprint to the very best of our abilities," Begley says. "My message is think about legacy, think about the future beyond your life, think long-term and find a conservation project that's important to you and support it. The reward will be immense, beyond your imagination. And be ambitious ... The most important thing you can hand on to your children is the natural world - in the same or better condition than you received it." www.betterancestors.org
Understanding Antarctica
Whether it's climate change, microfibres in the ocean, or loss of biodiversity, the impacts of human activity are also being seen in Antarctica. Scientists, researchers and organisations like Greenpeace are monitoring these changes in an effort to create a baseline but, as University of Exeter marine scientist Kirsten Thompson says: "It's time we put conservation first. Seems obvious to me." www.betterancestors.org
Revisiting tohorā
A year of wandering the southern oceans, following ancient migration routes in search of food—that’s the tantalising glimpse of whale life that a tohorā/southern right whale nicknamed Bill has given University of Auckland researchers. Thanks to a satellite tag deployed by a team led by Emma Carroll in 2020, Bill has now provided the longest record of tohorā migration ever captured. Usually, satellite tags stop working after around six months. Bill’s tag, however, is still transmitting more than a year later. Bill left the Auckland Islands in August 2020 and travelled thousands of kilometres into waters south of western Australia, before moving far off into the Indian Ocean, almost halfway to Africa. Then, he turned south and swam thousands more kilometres to the Antarctic ice edge. Over several months, he worked his way back along the edge of the pack ice, finally returning to the Auckland Islands in June, having traveled well over 15,000 kilometres. Another tagged whale, Tahi, also travelled far into the Indian Ocean before returning to the Auckland Islands. “We had no idea that they were going so far west,” says Carroll. “Bill and Tahi went a third of the way around the world and back. That’s unprecedented. [caption id="attachment_432915" align="alignnone" width="600"] Photographer Richard Robinson floats above the seafloor holding a VR camera, waiting. The 80-tonne whales, curious and confident, are ideal subjects—approaching slowly, orbiting gracefully and drifting away when they’re satisfied they’ve got to know you.[/caption] “It’s showing that these whales are using far more of the ocean than we thought. Which is great, because if one area isn’t that productive, but the other is, they’re still getting a lot of kai. It suggests the population has resilience.” Carroll and her team have just returned from the Auckland Islands, where they deployed another 11 satellite tags. “We want to be able to match their satellite tracks against currents, productivity, marine heatwaves, and all kinds of things. At the moment, we can see what they’re doing, but we need more data to understand why they’re doing what they’re doing.” As for Bill, well, at the time of writing, he is still transmitting—currently halfway back to western Australia, off on another lap of his extraordinary life. His progress, and that of this years’ tagged whales, can be seen at tohoravoyages.ac.nz
Where do shags come from?
Reconstructing the family tree of New Zealand’s blue-eyed shags has enabled scientists to unravel their past—and may help determine their future. The blue-eyed shag family includes bird species from all around the country: the rare king shag from the Marlborough Sounds, the Otago shag, the Foveaux shag, the extinct (but recently discovered) kōhatu shag from Northland, and species on the Chatham, Auckland, Campbell and Bounty islands, plus more-distant relatives on other subantarctic islands and in South America. Nic Rawlence from the University of Otago set out to track the evolution of the entire group, and his team’s genetic research revealed the birds evolved in South America. This is unusual for New Zealand birds, which most often arrive from Australia on the westerly winds. Blue-eyed shags were probably blown off course into the Southern Ocean and island-hopped around the subantarctic before arriving here around 2.5 million years ago and rapidly diversifying. That there are so many different species here is because of a paradoxical personality trait of blue-eyed shags. Though shags are obviously prone to accidental oceanic travel, once they find somewhere they like, they don’t stray far from home. That meant each small population was isolated from the rest and evolved independently. Then the ice ages struck, and Antarctic sea ice expanded all the way up to the more southerly subantarctic islands, spelling the end for the blue-eyed shags living there (the birds feed in shallow waters near their colonies, and when those froze over, they would have starved). When the ice retreated during a warmer period, blue-eyed shags recolonised the Southern Ocean from South America—but that later wave of migrants couldn’t get a foothold in New Zealand, as shags on the mainland had survived. “There were already blue-eyed shags that were happy, that were filling the job vacancy for blue-eyed shag,” says Rawlence. Genetic evidence confirms what biologists already knew about the family: “They are very, very prone to disturbance,” says Rawlence. “Whether that is human disturbance, polluting the oceans, or overfishing.” That makes them sentinels for the health of the Southern Ocean. “Working out how they evolved and how they’ve responded to past climate change can help us think about how they will respond into the future.”
Plant colony
You can buy a staghorn fern at any garden centre and grow it like a pot plant. But in the wild, the ferns grow in a way that’s changing our understanding of biological complexity. Latched onto branches of rainforest trees, staghorn ferns (Platycerium bifurcatum) evolved to live in colonies on Lord Howe Island off Australia’s east coast, with individual ferns fitted like puzzle pieces and working together to collect water for the benefit of all colony members. The level of job division is such that about 40 per cent of individuals forgo reproduction. Social colonies, with strict division of labour and reproduction, are nothing new in the animal kingdom, says Victoria University of Wellington biologist Kevin Burns. Social insects—bees, ants, termites and some wasps—are the best-known examples of colony-building behaviour, but it has also evolved independently in crustaceans (certain species of shrimp) and even mammals (naked mole rats). But Burns’ research describes the first time it’s been observed in plants. Colony-building behaviour, or eusociality, is the most recent of eight major evolutionary transitions to more complex life. Burns says eusociality is defined by colonies that include several generations of adults, and dividing labour and care for offspring co-operatively. Staghorn ferns may not fit the strictest definition, and are unlikely to have rigid job division like termites. “I suspect they go through a succession, starting off being a reproducer, then maybe a collector, and they shift as the colony develops,” he says. But the important point is that colony life is not restricted to animals. “Plants can walk that evolutionary path in the same way, without a brain—and that’s a huge leap forward.”
Seabird oddity
Tubenose seabirds—albatrosses, petrels, shearwaters and storm petrels—pretty much always follow the rules. Breed in the summer, when there’s more kai to catch. Mix up the length of foraging trips when feeding a chick: a few short foraging sessions for every long-distance feed. Mum and Dad pick different fishing spots and strategies, diversifying their options. Westland petrels break all the rules. They breed in the winter. Their foraging trips are always the same length—short, even though their wing structure means they’re capable of longer flights. And both parents fish in the same old spot. (Only 12 tubenose species are known to adopt these non-conformist habits.) To understand why and how Westland petrels successfully raise chicks with such an unusual approach, researchers tracked their movements using GPS loggers and accelerometers. The international team, including scientists from Te Papa, found that the Westland petrels were fishing around 150 kilometres off the coast, where the continental shelf slopes into submarine canyons: a reliable, local prey field that shapes their behaviour. Fishing peaks during the first few hours of darkness, suggesting that the petrels target bioluminescent fish and squid species that migrate daily up and down the water column. Westland petrels are endangered, and the small size of their foraging range—which coincides with a hoki trawl fishery—could pose problems in a food shortage, while their nesting burrows in the hills have previously been threatened by human development.
Kiwi need more bugs
For many kiwi, there’s little chance of survival unless a ranger plucks them from the wild while they’re still in the egg. These birds hatch and grow up in captivity, then are returned home once they’re big enough to fight off stoats and rats. This system has saved the lives of hundreds of kiwi, but may have some unintended consequences: the microbes in the gut of kiwi raised in captivity are very different from those of birds which hatched in the wild. Kiwi chicks hatch ready to forage, says Manaaki Whenua microbial ecologist Manpreet Dhami. “From the very beginning they are digging around in the soil and foliage, looking for food and thus acquiring their first microbes.” Captive kiwi, on the other hand, are fed a mix of ox heart, cat biscuits and rolled oats—food that is “nutritionally appropriate but microbially a far cry from their natural diet”. If a bird catches an infection, it’s treated with antibiotics and then given probiotics to help restore its microbiome. Dhami and her team analysed faeces from wild birds and kiwi hatcheries, and found the microbiomes of wild birds were more similar to each other than those of captive birds—even when the wild kiwi were from different locations. The wild microbiome includes bacteria that may have a protective role against illness or help with food digestion, while the captive kiwi microbiome is simpler and less diverse. Studies on other birds—parrots, chickens and ostriches—have found a connection between less diverse microbiomes and a higher risk of disease. “As more and more birds go through the captive rearing process, we are creating a population of birds that are lacking that exposure to microbial diversity, and perhaps undercutting the development of natural defences,” says Dhami. Captive rearing is essential to the survival not just of kiwi but many other threatened birds, kākāpō and takahē among them. The team is now working on a new diet for captive kiwi—one that’s more natural and has more bacteria.
Singing test
Do forests fall silent after a drop of the poison 1080? Scientists recorded birdsong in the Wairarapa’s Aorangi Range before and after 1080 operations in 2014 and 2017, as well as in the Northern Remutaka Ranges, which didn’t receive the poison. (1080 is intended to kill possums.) Analysing the hundreds of recordings, researchers from Victoria University of Wellington found birdsong levels were the same, or higher, in areas treated with 1080, compared to untreated areas of forest. The majority of birds were judged to be unaffected by 1080 on the basis of their calls, but two species were heard from less following the drops: chaffinches and tomtits. The researchers believe chaffinches, an introduced species, may have consumed 1080—the birds normally eat grain—and say further research is needed about how native tomtits may be affected by the poison.
Bird’s eye view
Humans can see three primary colours. Birds can see four. What does an ultraviolet world look like? And why did birds develop the colours they wear today?
Bored or hungry
Can you stop a cat from hunting? University of Exeter researchers tested whether improving a cat’s nutrition or exercise reduced its number of kills. Over three months, the researchers trialled different options on 219 households involving 355 cats in southwest England, focusing on interventions that increased the cats’ quality of life. Introducing high-meat protein food reduced the number of animals cats killed by 36 per cent, which supports the theory that cats hunt to compensate for micronutrient deficiencies in their diet. Cats who played with a feather toy for five to 10 minutes a day hunted 25 per cent less. Meanwhile, cat bells had no effect on hunting, while brightly coloured collars reduced the number of birds hunted, but not the number of mammals. (The cats didn’t like the collars, noted the researchers.) Use of a “puzzle feeder”, where cats had to solve a problem to access food, increased the cats’ hunting efforts by 33 per cent. To reduce the impact of domestic cats, write the study’s authors, “Owner behaviour is as important as cat behaviour.”
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