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Tuesday, September 19, 2023

Geoengineering is happening, AI wants to talk with animals, and why we aren’t going to live in space

Geoengineering is happening, AI wants to talk with animals, and why we aren’t going to live in space

Geoengineering is happening, AI wants to talk with animals, and why we aren’t going to live in space

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DNA Pulled From Paw Prints May Help Researchers Study Elusive Polar Bears

As rising temperatures threaten the Arctic mammals, scientists are turning to new, non-invasive methods to study them

Polar bears live in rugged, hard-to-reach places in the Arctic. U.S. Fish and Wildlife Service Polar bears are mostly solitary creatures that can cover huge swaths of rugged, remote terrain in Canada, Norway, Russia, Greenland and Alaska. This makes them difficult to find and study—even as scientists have lots of questions about how they’re faring amid rising global temperatures. Now, an emerging research method may be able to help. Scientists can identify individual bears by analyzing tiny amounts of DNA they leave behind in footprints as they traipse through the snow, according to two papers published recently in the journal Frontiers in Conservation Science. This technique could make it cheaper, easier and safer to study polar bears and other similarly elusive creatures, which may ultimately bolster conservation efforts. Polar bears face numerous threats related to human activities, including declining sea ice from human-caused climate change, toxic pollution and habitat loss. Historically, when scientists have wanted to collect genetic material from polar bears, they’ve had to locate, tranquilize and capture the gigantic mammals, which can weigh up to 1,700 pounds. This invasive method can be dangerous for both the bears and the researchers; in addition, some Indigenous communities oppose the practice over animal welfare concerns or fears of eating meat that’s possibly tainted by sedatives. So, rather than relying on DNA obtained from the creatures directly, scientists wondered if they could utilize other means of collecting genetic material. They turned their attention toward environmental DNA, also known as eDNA, which animals leave behind as they wander through landscapes. They do so by dropping dead skin cells, shedding bits of fur and depositing feces, for example. Past studies have successfully used eDNA to study other types of animals, including birds and fish. But this is the first time anyone has been able to link eDNA with an individual animal, reports Science’s Susan Cosier. In a study published in Frontiers in Conservation Science this summer, researchers described how they identified six individual polar bears and determined the sex of each—based only on snow gathered from the surface of their tracks. The team investigated a total of 130 polar bear paw prints and was able to successfully isolate DNA from 46 percent of them. In a second paper, published in the same journal this week, a different group of researchers demonstrated similar capabilities with both wild and captive Alaskan polar bears and Swedish Eurasian lynx, as well as a captive snow leopard. From snow gathered from the animals’ footprints, the team isolated DNA in all the captive samples, 59 percent of the wild lynx samples and 88 percent of the wild polar bear samples. They also linked DNA from the wild paw prints with 12 individual bears. Researchers decided to home in on eDNA from paw prints, rather than from feces, because DNA degrades as it passes through the animal’s digestive system. Tracks, meanwhile, “usually contain fresh cells, and the DNA is intact because of the cold ‘storage’ temperature,” says ecologist Micaela Hellström, lead author of the study published this week and co-founder of the eDNA research company MIX Research Sweden AB, in a statement. Moving forward, eDNA likely won’t replace all other polar bear research methods entirely. But scientists may be able to use it in concert with other techniques and technologies, such as tracking collars and other wearable devices, aerial studies using synthetic aperture radar and artificial intelligence models, and “bear-dar” detection systems. “It’s like putting together a puzzle: You get small pieces of information from different sources,” says Jon Aars, a biologist at the Norwegian Polar Institute who was not involved in the new studies, to Science. Get the latest stories in your inbox every weekday.

A great year to be a cabbage white butterfly: why are there so many and how can you protect your crops?

Conditions this year have been perfect for a cabbage white population boom, but you can do a few things to stop their caterpillars from shredding your plants.

Christian Mueller/ShutterstockCabbage white butterflies – Pieris rapae – are one of the most common garden visitors across southern and eastern Australia. The butterfly looks elegant in white with black dots on its wings: females have a pair of black spots and males a single spot on each forewing. But their velvety green caterpillars are ravenous beasts on brassicas – the plant family that includes common vegetable crops such as cabbages, cauliflowers, broccoli, kale and bok choy. The species was accidentally introduced into Melbourne in 1929 from Europe. Since then, cabbage whites have spread all over Australia, finally reaching Perth in 1943. Because of their caterpillars’ addiction to eating brassicas, it is one of the most pervasive pests of any crop worldwide. Recent conditions have been favourable, resulting in large numbers of cabbage whites. One female can lay up to 800 eggs. When they hatch, the caterpillars prefer densely planted hosts in moist, warm habitats. The caterpillars’ biomass can double each day, making them one of the fastest-growing cabbage-feeding caterpillars. One female cabbage white can lay up to 800 eggs that hatch into very hungry caterpillars. Anna N Chapman/Wikimedia Commons Read more: Why red fire ants and yellow crazy ants have given themselves a green light to invade Australia Why are there so many this season? Cabbage whites’ ability to exploit the moist and warm conditions over the past winter are one reason they are so pervasive at the moment. In a mild year caterpillar numbers build up quickly and can badly damage crops. Scott Nelson/Flickr They can also cope with cold. The pupae – the stage in which a caterpillar metamorphoses inside a cocoon into an adult butterfly – can survive temperatures as low as -20°C. Their cells can produce antifreeze proteins, which lower their freezing point if it does get cold. Milder winters mean the overwintering pupae emerged and mated early. The female adults soon started to lay their eggs on planted brassicas. The next generation of caterpillars can then start feeding without being predated on as their natural enemies take longer to emerge after milder weather. Cabbage white numbers then build up extraordinarily quickly. What’s the appeal of brassicas? The caterpillars are attracted and addicted to chemicals found in brassica leaves. These are the mustard oil glucosides (glucosinolates) – particularly sinigrin, which initiates caterpillar feeding. Adult females are attracted to brassicas by another glucosinolate – glucobrassin – which prompts them to lay their eggs on the leaves. Females can “taste” these chemicals with hairs on their front legs. The females also prefer greener plants – which they’ll find in well-watered and fertilised vegetable gardens – to lay their eggs. Female cabbage whites prefer greener plants to lay their eggs. bramblejungle/Flickr, CC BY-NC How to live with them A key way to control the caterpillars is to deny them access to your crops in the first place. Once the leaves start developing, cover the crop with insect-proof mesh. You can use garden hoops or bamboo as a supporting frame for the mesh. When you remove the mesh to water or weed, do it in the early morning or late afternoon when the adults are not flying. White butterfly decoys suspended on sticks generally don’t work to stop females laying their eggs. There is no evidence cabbage white females are territorial. It can be useful to provide a “sacrificial” plant. Leave these out in the open to attract the adult female to lay her eggs. As caterpillars increase in numbers, they will start to attract beneficial predators and insect parasitoids that lay their eggs on the caterpillars. Parasitoids are primarily wasps and can be very effective biocontrol agents. Their larvae feed on the bodily fluids or the internal organs of the host caterpillar, eventually killing it. These beneficial insects need a nectar source to stay active. They will be attracted to gardens that are a bit “messy” with different habitats and flowers. Remember, some green caterpillar-like animals are good guys. So, if you are fond of squishing the caterpillars, make sure they are the ones eating the foliage; not the voracious predators, especially aphids, eating the herbivores. Read more: The secret agents protecting our crops and gardens Just to make things more interesting, caterpillars, in general, that are feeding are about 100 times more likely to fall prey to predators and parasites than caterpillars that are hiding. Longer caterpillar feeding bouts usually happen on plants with lower nitrogen levels – so if you have a sacrificial plant, don’t fertilise it. It can also help not to plant all your brassicas together. Mix up your vegetables and herbs. This provides your prized kale with companion plants and makes it harder for caterpillars to move from one plant to another. Companion planting allows beneficial insects to find hiding places closer to the caterpillars, and also makes it harder for the female butterflies find your brassicas. Read more: These 3 tips will help you create a thriving pollinator-friendly garden this winter Companion planting helps protect brassicas from cabbage whites while also attracting beneficial insects. VeMa/Shutterstock Avoid pesticides as much as possible Don’t spray your garden plants with pesticides unless you desperately need to feed lots of family or are a serial entrant in the fruit and vegetable exhibition at your local show. The cost is huge relative to the benefit the chemicals bring you. In most cases you will be killing off many beneficial creatures in your garden. Read more: The battle against bugs: it's time to end chemical warfare If you must, the least harmful spray for humans and other natural enemies of the cabbage white is Dipel. This is an insecticidal product containing toxins derived from a bacterium, Bacillus thuringiensis kurstaki (Btk), which occurs naturally in soil and on plants. But it may be toxic to other butterflies and moths that pollinate your veggies, so be very careful where and when you spray. Protecting your patch with mesh, rather than spraying, and providing space and food for natural enemies are great ways to keep the diversity up in your garden. Allowing a little bit of damage to your prized backyard crops enables some interesting biological interactions to occur in areas where it may have been missing for decades. Nigel Andrew has received funding from the Australian Research Council, Grains Research Development Council, Meat and Livestock Australia, NSW Environmental Trust, and NSW Local Land Services. He is a Board member of the Ecological Society of Australia, the Australian Fulbright Alumni Association, and the NSW Entomological Society..

The slow race to save Brittany’s rare Quimper snails from a tramway – one gastropod at a time

In Brest, this protected species, found only in Brittany and the Basque Country, is being painstakingly moved to a new home before their habitat is destroyedOn a drizzly November evening, ecologists in Brest, Brittany, are rooting through the damp undergrowth flanking an unmarked and unlit track going nowhere. They are searching for Quimper snails. It’s a slow and meticulous job: the snails are small, come out only at night and prefer the dank, dark cover of soggy leaves and twigs.Soon, their natural habitat here will be destroyed by a €200m (£170m) public transport project, which includes a new tramway. Continue reading...

On a drizzly November evening, ecologists in Brest, Brittany, are rooting through the damp undergrowth flanking an unmarked and unlit track going nowhere. They are searching for Quimper snails. It’s a slow and meticulous job: the snails are small, come out only at night and prefer the dank, dark cover of soggy leaves and twigs.Soon, their natural habitat here will be destroyed by a €200m (£170m) public transport project, which includes a new tramway.As environmental damage cannot be avoided, it has to be reduced and compensated for. So the Quimper snails, only known to exist in northern Brittany and the Basque Country, are being saved, one gastropod at a time, and compensated with a new home.“Here’s one,” says Timothée Scherer, a conservationist at Biotope, an ecological consultancy. He holds in his palm a copper-coloured translucent shell no bigger than a pinkie fingernail, whose occupant has retracted its horns and is shunning the unexpected limelight.It is a race against time to find as many of the snails as possible before the temperature drops and they hibernate. Scherer admits there appears to be an abundance of the snails in the undergrowth, but as a protected species they have to be found and saved.“Because they only exist in two places in the world there is obviously a risk of extinction,” he says. “Elsewhere there are very few.”The greatest threat to the Quimper snail is the deforestation of its natural habitat and the prevalence of non-native treesThat Brest’s multimillion-euro public transport scheme should be forced to consider the fate of flora and fauna is a welcome surprise. But it is not the first time the Quimper snails have fought the odds and won, much to the chagrin of local developers.In 2012, the city’s football club, Stade Brestois, was forced to halt its plans for a new training centre after it was discovered that the proposed site was home to the snails. The centre was eventually built on a snail-free site.Mindful that it could face similar objections, Brest Métropole authority commissioned an environmental impact study into the proposed transport plan that includes a second tram line, new bus route, 7 miles (12km) of new cycle lanes and nine hubs where the various forms of transport converge, as well as an inventory of the vegetation and animals that would be affected.The study found 200 species in the construction area, 75 of which are officially protected. Among them were birds, bats and reptiles, most of which were deemed able to relocate. The slow-moving snails, however, presented a problem.Once saved, the Quimper snails will be moved to a new home about 200 metres away. Photograph: Fred Tanneau/AFP/Getty ImagesThe Quimper snail, or Elona quimperiana, is an air-breathing gastropod protected at French and EU level. Unlike most common snails, its brown, transparent shell lies flat. Its predators include hedgehogs, birds, toads, salamanders, beetles and some worms, though the greatest threat is the deforestation of its natural habitat and the prevalence of non-native trees.Although the species is not considered directly endangered in France or Spain, Quimper snail populations are said to be “fragile” and their limited geographic situation makes them vulnerable.“Our aim is to clear the area of individuals before the work starts,” Scherer says, placing another Quimper snail in a plastic bucket lined with fresh mulch. “We will also scrape off the topsoil so we are moving the snails’ environment with them.”skip past newsletter promotionThe planet's most important stories. Get all the week's environment news - the good, the bad and the essentialPrivacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Privacy Policy. We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply.after newsletter promotionNetting barriers have been put around the cleared areas to stop the snails returning.Work to lay tramlines has already begun, and the new transport network is expected to open in 2026. Officials suggest heeding environmental concerns has added an extra year to the project that began in 2019.“Environmental challenges can be seen as a constraint to projects but we view it as an important issue. It doesn’t have to be a competition,” says engineer Victor Antonio, director of mobilities for Brest Métropole local authority. Preservation is now built into all the city’s development projects, he says.Five hundred trees will also have to be cut down, but 1,500 new trees will be planted. When the work has finished, conservationists hope those creatures that have taken flight or scuttled away will return.Placing the snails in their new habitat, about 200 metres from their old home, Scherer says conservationists will be keeping an eye on them: “This operation takes time but we don’t know how important these individual snails will be for the species as a whole. Each individual snail we find here may be important in allowing the species to remain here.“And by protecting the snails, we’re also protecting its habitat and a whole range of species that live there,” he says.

Scarier Than Lions – Animals Around the World Fear This “Super Predator”

A new study reveals that elephants, rhinos, giraffes, and other wildlife fear this predator far more than lions. Lions have long been regarded as the...

Recent research in South Africa’s Greater Kruger National Park has uncovered that local wildlife, including elephants and giraffes, fear humans more than lions (pictured above), highlighting the global impact of humans as “super predators” and posing new challenges for wildlife conservation. Credit: Daniel Rosengren A new study reveals that elephants, rhinos, giraffes, and other wildlife fear this predator far more than lions. Lions have long been regarded as the apex predators, often referred to as the “king of beasts,” but a new study suggests that on the African savanna, elephants, rhinos, giraffes, and other mammals exhibit greater fear of a different threat: humans. This finding adds significant weight to the increasing body of evidence from global wildlife research, which indicates that the fear of humans as the “super predator” is widespread among animal populations around the world. VIDEOElephants aggressively approaching, and attacking, speakers broadcasting lion vocalizations. Credit: Liana Zanette / Western University The Impact of Human Presence The new findings by Western University biology professor Liana Zanette, in collaboration with one of the world’s leading lion experts, Craig Packer from the University of Minnesota, and others, were published today in Current Biology. Working in one of the world’s premier protected areas, South Africa’s Greater Kruger National Park, Zanette and her colleagues experimentally demonstrated that local wildlife was twice as likely to run, and abandoned waterholes in 40 percent faster time, in response to hearing human voices compared to hearing lions or hunting sounds (dogs barking or gunshots). Elephant still image from camera recording. Credit: Liana Zanette / Western University Near 95 percent (94.7) of species ran more or abandoned waterholes faster in response to humans than to lions, with giraffes, leopards, hyenas, zebras, kudu, warthog, and impala all running significantly more from the sound of human voices than the sound of lions, and elephants and rhinos abandoning waterholes significantly faster upon hearing humans than hearing lions. VIDEORhinoceroses and elephants abandoning waterholes upon hearing humans. Credit: Liana Zanette / Western University Ecological Consequences and Global Perspective “These findings add a new dimension to our worldwide environmental impacts,” said Zanette, a renowned wildlife ecologist. “The very substantial fear of humans demonstrated here, and in comparable recent experiments, can be expected to have dramatic ecological consequences, because other new research has established that fear itself can reduce wildlife numbers.” Global surveys show humans kill prey at much higher rates than other predators, making humans a “super predator.” VIDEOGiraffe, leopard, hyena, zebra, kudu, warthog and impala running in response to hearing humans. Liana Zanette / Western University “Consistent with humanity’s unique lethality, data from North America, Europe, Asia, and Australia, and now our work in Africa, is demonstrating that wildlife worldwide fear the human ‘super predator’ far more than each system’s non-human apex predator, like lions, leopards, wolves, cougars, bears, and dogs,” said Zanette. To conduct their experiment, Zanette and the team deployed hidden automated camera-speaker systems at waterholes that, when triggered by an animal passing within a short distance (approximately 10 meters or 30 feet), filmed the response of the animal to hearing either humans speaking calmly in locally-used languages, lions snarling and growling, hunting sounds or non-threatening controls (bird calls). “These results present a significant new challenge for protected areas management and wildlife conservation, because it is now clear fear of even benign humans, like wildlife tourists, can cause these previously unrecognized impacts,” said Zanette. Reference: “Fear of the human “super predator” pervades the South African savanna” by Liana Y. Zanette, Nikita R. Frizzelle, Michael Clinchy, Michael J.S. Peel, Carson B. Keller, Sarah E. Huebner and Craig Packer, 5 October 2023, Current Biology.DOI: 10.1016/j.cub.2023.08.089

Save the axolotl: Urgent "Adoptaxolotl" campaign begins in Mexico

Here's how to "adopt an axolotl" — or buy it dinner and help fix its adorable little house

They're calling it Adoptaxolotl. It's the latest relaunch of a fundraising campaign by ecologists at Mexico’s National Autonomous University to save the endangered (and adorable) type of underwater salamander known as the axolotl. The amphibian critters have become popular household pets in the U.S., but as reported by the Guardian Thursday, almost all 18 species of axolotl remain critically endangered as their main habitat is threatened by increasing water pollution and invasive species. With Mexico's environmental department facing an 11% funding cut, scientists are turning to the public for help.  “What I know is that we have to work urgently,” ecologist Alejandro Calzada told the Guardian. "We lack big monitoring of all the streams in Mexico City ... For this large area it is not enough.”  That monitoring is the first spending priority for ecologists, who hope to begin gathering an updated headcount on the animals in March. It would be the first since 2014, though a recent international study found less than 1,000 Mexican axolotls left in the wild, whereas Mexican scientists could once find an average of 6,000 per square kilometer in the country. Last year, the scientists managed to raise more than $26,300 for an experimental captive-breeding program. This year, you can virtually "adopt" an axolotl for $35, and you'll be sent live updates about your axolotl's health along with an adoption certificate. Those on a budget who still want to help can also buy an axolotl a virtual dinner or help one fix up its little house — a donation rewarded by a personalized letter of axolotl gratitude. 

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