4-12-21 The frequencies of a vibrating spider web have been made into music
Spiders are mostly blind, but their webs are sensitive to disturbances, which they detect with their legs. Now, scientists have created an audio-visual virtual reality take on this that converts a web’s vibrations to sounds we can hear, giving us an idea of what it might feel like to be a spider. “The spider web can be viewed as an extension of the body of the spider, in that it lives within it, but also uses it as a sensor,” says Markus Buehler at the Massachusetts Institute of Technology, who presented the work at a virtual meeting of the American Chemical Society. “When you go into the virtual reality world and you dive inside the web, being able to hear what’s going on allows you to understand what you see.” Because of differences in the length and tension of each strand of a spider’s web, they emit a different frequency when disturbed and can even be used to send out signals or communicate with other spiders when the web’s owner taps on the strands. Buehler’s team used laser imaging to create a 3D map of webs made by tropical tent-web spiders (Cyrtophora citricola). They identified each thread’s vibrating frequency through its size and elasticity, then converted those frequencies into ones that can be heard by humans. By piecing the visual and auditory layers together, users connect the sounds to the threads they see, mimicking a spider surveying its world, he says. The team made some artistic decisions, such as using a synthesiser with a harp-like sound. Threads that are closer to the listener or connected to many others sound louder than others. For Buehler, who has spent hours listening to the noises the virtual webs make, they no longer just sound dissonant, but begin to have identifiable structure. “We believe we have an accurate reflection of what the spider would ‘see’,” he says.
4-11-21 Saving green turtles... by cooling their eggs
The future of Australia's green turtles is under threat by climate change - but not how you might think. Warmer sand temperatures are leading to way more females being hatched than males. Ade Adepitan travels to breeding spot Heron Island, in the Great Barrier Reef, to find out how conservationists are helping to save the reptiles.
4-10-21 Female monkeys call to males when they see a predator approaching
When faced with a predator, female putty-nosed monkeys will call males to help protect them from the threat. Putty-nosed monkeys (Cercopithecus nictitans) live in the forests of West Africa in groups of one male with multiple females and their offspring. The male will tend to roam further from the group and leave females to forage for themselves, but the females and lone male will alert each other when predators are nearby. Communication in this species differs based on sex. Females produce a single “chirp” to alert others when any form of predator is nearby, while the lone males will use different calls based on the type of predator spotted: “pyow” calls for those on the ground, like leopards, and “hack” calls for predatory eagles. Claudia Stephan at the Wildlife Conservation Society, Republic of the Congo, wanted to see how female and male putty-nosed monkeys differ in their response to these calls during a predatory event when the male is roaming relatively far from the group. With her colleague Frederic Gnepa Mehon, also at the Wildlife Conservation Society, Stephan located 19 different groups of monkeys in Nouabalé-Ndoki National Park. For each group, the two researchers and their colleagues waited until the lone male was around 20 metres from the group. One volunteer, covered in a leopard print fabric to mimic a predator, then approached either the lone male or the group of females. If the “leopard” approached the lone male, he responded by making a “kek” call. Stephan says this call hadn’t been recorded during research on male putty-nosed monkeys in other regions, so could be a local dialect. But Stephan points out that earlier studies into alarm calls involved stationary leopard models, rather than a moving leopard model. “It could also be that moving danger on the ground elicit ‘kek’ calls, and any danger on the ground is ‘pyow’ calls,” she says.
4-9-21 Is Netflix's Seaspiracy film right about fishing damaging oceans?
A documentary about the fishing industry's impact on sea life and the oceans has caused a lot of debate. Many viewers have been saying they will no longer eat fish after watching the film, and expressed shock at the industrial scale of fishing. Others have argued it oversimplifies a complex issue - many communities depend on fishing for their livelihoods and for food, and are in fact practising sustainable catching methods. We looked into some of the main claims in the Seaspiracy film on Netflix. "If current fishing trends continue, we will see virtually empty oceans by the year 2048," says Ali Tabrizi, the film's director and narrator. The claim originally comes from a 2006 study - and the film refers to a New York Times article from that time, with the headline "Study Sees 'Global Collapse' of Fish Species". However, the study's lead author is doubtful about using its findings to come to conclusions today. "The 2006 paper is now 15 years old and most of the data in it is almost 20 years old," Prof Boris Worm, of Dalhousie University, told the BBC. "Since then, we have seen increasing efforts in many regions to rebuild depleted fish populations." There are plenty of examples of overfished stocks, the catching of unwanted fish, and habitat loss, as well as issues with pollution and climate change, says Prof Worm. But he points out there are also "countless efforts under way to repair the damage that has been done". Other experts have taken issue with the original claims in the 2006 study. There was an "unrealistic extrapolation way beyond the bounds of available data", says fisheries expert Michael Melnychuk, from the University of Washington. He says the study was not well received by the fisheries science community, and that this prediction has "persisted ever since". "Overfishing is certainly a problem in many regions of the world, but in regions where fisheries management regulations are based on scientific evidence and properly enforced, most fish stocks are doing well," says Dr Melnychuk. (Webmaster's comment: Killing a one ton shark just so we can eat a 10 pound fin is so wrong!)
4-9-21 Ocean noise: Study to measure the oceans' 'year of quiet'
Ocean scientists around the world are studying the "unique moment" of quiet created by the pandemic. The researchers have called their vast listening experiment: The year of the quiet ocean. "Lockdown slowed global shipping on a scale that would otherwise be impossible," explained Prof Peter Tyack from the University of St Andrews. The scientists plan to listen to the ocean soundscape before, during and after lockdown. They have identified 200 ocean hydrophones - underwater microphones that are already in place around the global ocean. "So the idea is to use those to measure the changes in noise and how they affect marine life - like calling whales or fish choruses," Prof Tyack said. "Just like people and cities may have noticed that, with much less traffic noise and human activity, you hear more birdsong or maybe see more wildlife in your own environment, we need ways to monitor that in the ocean." The aim is not only to measure how the pandemic briefly changed the ocean soundscape, but to take the opportunity to find out how decades of increasing ocean noise has affected marine life. Combined with other methods such as animal tagging, researchers hope this will reveal the extent to which noise in "the Anthropocene seas" affects life in the deep. "We've had such a big impact on the world's oceans - with pollution and climate change - but the thing about noise is that it's relatively easy to turn down the volume," said Prof Tyack. Prof Jennifer Miksis-Olds, an ocean acoustics expert from the University of New Hampshire said that the data from the year of the quiet ocean would provide insight into much more than just noise pollution. "There is so much we can learn from just listening to the sound of the ocean," she said. "One of my goals is to build a global ocean soundscape map, where you could see the sounds of shipping routes, see migration patterns of whales - from their song - and even learn about climate change from the sounds of icebergs calving."She added that listening to the ocean could help to "find the balance" between human activity and the natural processes in the ocean.
4-7-21 Dead eagles found across the US had rat poison in their blood
In a sample of eagles from across the US, rat poison was found in about 80 per cent of the birds. This widespread exposure to toxic chemicals could impair their health or even lead to death. “This really suggests that despite the best efforts to use these compounds wisely and minimise the opportunity for the raptor species to be exposed, they’re still somehow getting exposed,” says Mark Ruder at the University of Georgia. Between 2014 and 2018, Ruder and his team determined the cause of death for 303 golden eagles (Aquila chrysaetos) and bald eagles (Haliaeetus leucocephalus), which were sent to them from around the US. Some deaths couldn’t be explained, but the team determined that 4 per cent of the eagles died directly as a result of rat poison. They tested 133 of the birds for anticoagulant rodenticide, the most common rodenticide, which can also target opossums and beavers, and found that 82 per cent of the birds had it in their body. There was a high prevalence of what are known as second-generation anticoagulant rodenticides, which are highly toxic and can remain active for months after ingestion. These have been tightly regulated by the US Environmental Protection Agency since 2011 and are only available for commercial use. Eagles often scavenge, and rodents killed by the poison could become their food, although it still isn’t clear how exactly the eagles came into contact with it. It is also unclear whether the poison can affect reproduction or impair their health in other ways, says Ruder. “Such widespread exposure indicates that this issue is more than a localised phenomenon, and if there are widespread health impacts they may occur throughout the population,” says Garth Herring at the US Geological Survey, who wasn’t involved in the study.
4-7-21 Animal intelligence is so common, we must rethink our view of wildlife
Tests show that a growing number of animals have the flexible, problem-solving thinking we once thought of as our own. It's time to treat creatures with more respect. CALL it human curiosity, but it is natural to wonder what a pet is thinking, or to ponder, as philosophers and latterly consciousness researchers have, what it is like inside the mind of a bat or a bird or an octopus. We are inching closer to cracking the secrets of animal minds – and they aren’t what we expected. From Snowball the dancing cockatoo to sheep that can recognise celebrities, there are plenty of examples of animals doing clever things. Nevertheless, such antics could be mere party tricks, not a manifestation of something resembling the “general” intelligence that allows us to think our way through life’s challenges. In fact, many biologists have long assumed that animals don’t do much thinking at all, acting mostly on instinct instead. The idea was so ingrained that our curiosity didn’t extend to testing it – until recently. Obviously, you can’t put animals through human IQ tests. Nor would we necessarily want to, given that those tests provide only a limited and selective view of intelligence. But with a bit of ingenuity, you can devise a battery of tasks appropriate for a particular species. “We search for intelligent life elsewhere, but there is more on Earth than we imagined” A growing number of animals are passing such tests. These include creatures with tiny brains, such as mice, and others, like ravens, that don’t even have the brain structures we usually associate with intelligence. Clearly, humans aren’t alone in possessing a flexible, problem-solving sort of brain – or indeed attributes that build on that, such as culture. So we should be careful what traits we describe as uniquely human. But equally we should be careful not to anthropomorphise too much: no one can even be certain that other people think in the same way they do, let alone animals.
4-7-21 Human-like intelligence in animals is far more common than we thought
Stories of clever animals abound, from pigs playing video games to monkeys trading mobile phones – now tests reveal that they don't merely act on instinct but can think flexibly, like us. BARELY a month goes by without a new tale of animals behaving brightly. There are orangutans that craft umbrellas out of plant leaves, and chimps that employ stones as hammers with a technique that is uncannily similar to one seemingly used by our Stone Age ancestors. In Bali, long-tailed macaques steal from tourists and then exchange their swag for edible rewards – and they have learned to target high-value items as if they appreciate the basic principles of economics. Hyenas employ the art of deception, with low-status individuals sounding an alarm call that scares their rivals away from a tasty carcass. In one UK zoo, several parrots curse copiously, apparently to entertain visitors. Pigs have been taught to play video games, rats can learn the rules of hide-and-seek, and let’s not forget the golfing bees. Superficially, these behaviours certainly seem smart. But what do they really reveal about animal intelligence? The human mind is remarkable for its innovation and problem-solving across many different domains. Do other animals have the same sort of brains, or are their headline-grabbing antics no more than party tricks that require little complex reasoning? Scientists have begun devising elaborate tests to tackle this question. Like our own IQ tests, they allow researchers to assess the capacity of an animal’s mind, compare the mental abilities of different individuals and identify factors that lead to superior performance. The findings have been a revelation. They provide some fascinating insights into the anatomy of intelligence. And they may even shed light on the evolutionary origins of our own minds.
4-7-21 Yawning helps lions synchronize their groups’ movements
Subtle social cues may be embedded in a lion's lazy gape, new research suggests. Watch a group of lions yawn, and it may seem like nothing more than big, lazy cats acting sleepy, but new research suggests that these yawns may be subtly communicating some important social cues. Yawning is not only contagious among lions, but it appears to help the predators synchronize their movements, researchers report March 16 in Animal Behaviour. The discovery was partially made by chance, says Elisabetta Palagi, an ethologist at the University of Pisa in Italy. While studying play behavior in spotted hyenas in South Africa, she and colleagues often had the opportunity to watch lions (Panthera leo) at the same time. And she quickly noticed that lions yawn quite frequently, concentrating these yawns in short time periods. Yawning is ubiquitous among vertebrates, possibly boosting blood flow to the skull, cooling the brain and aiding alertness, especially when transitioning in and out of rest (SN: 9/8/15). Fish and reptiles will yawn, but more social vertebrates such as birds and mammals appear to have co-opted the behavior for purposes conducive to group living. In many species — like humans, monkeys, and even parakeets (SN: 6/1/15) — yawners can infect onlookers with their “yawn contagion,” leading onlookers to yawn shortly afterwards. Seeing the lions yawn reminded Palagi of her own work on contagious yawning in primates. Curious if the lions’ prodigious yawning was socially linked, Palagi and her team started recording videos of the big cats, analyzing when they were yawning and any behaviors around those times. Over four months in 2019, the researchers closely monitored 19 lions at the Greater Makalali Private Game Reserve, just west of Kruger National Park. The team found that lions that saw another member of the pride yawn were about 139 times as likely to yawn themselves within the next three minutes.
4-7-21 Tiny crystals give a plain fish twinkling, colorful dots under light
Puzzling fish twinkles from wide-banded hardyhead silversides might lead to ultra-tiny sensors. As light shines steadily on a silver slip of a fish, minuscule dots on the fish start flashing: blue, yellow, blue, yellow. The bodies “do not glow like luminous fish,” Masakazu Iwasaka, an interdisciplinary engineer at Hiroshima University in Japan has discovered. Instead of making their own light, it turns out that remarkable little photonic crystals in fish spots reflect certain wavelengths of light, alternating between blues and more greenish-yellows, he reports April 7 in Royal Society Open Science. Lots of biological materials have evolved tricks manipulating light. The iconic morpho blue butterfly doesn’t have a flake of blue pigment. It creates its dream-perfect sky blue with stacks of microscopic light-manipulating plates. So do blue-leaved begonias (SN: 11/28/16). Those fish reflectors are doing something similar in wide-banded hardyhead silversides (Atherinomorus lacunosus). “I found the flashing of a small spot by chance” while screening the dots no bigger than 7 to 10 micrometers across on fish backs, he says. Inside the reflective flash spots lie little platelets of the compound guanine that have grown in such a way that they can reflect colorful light depending on the angle. Guanine may sound familiar. It’s one of the four major coding units that pair up in storing DNA’s genetic information. What gives the fish guanine platelets particular abilities though remains a puzzle. Iwasaka suspects that inside a spot, platelets move in ways that change their apparent color and dazzle power. The blue-yellow light pulses only in living silversides. Dead fish just reflect white-white. Iwasaka hopes to create human-made counterparts to the fish reflectors. He proposes mimicking fishy structures for sensors far, far smaller than the period on a magazine page. Versions of little sparkling fish lights could fit into the world of micro-electromechanical systems (MEMS) to monitor conditions inside living tissues, responding to light or flashing themselves. In earlier work, he’s shown how guanine platelets can be manipulated in magnetic fields, suggesting that such sensors could be targeted and herded.
4-1-21 Ewes prefer to mate with submissive rams when given a choice
When female sheep get the choice, they would rather mate with a subordinate male than a dominant one. Dominant rams usually mate with ewes much more often than lower-ranking rams do. But they can literally run out of sperm from mating so much in a short period of time. And if they fathered all the lambs in a flock of sheep (Ovis aries), the group would have less genetic diversity, which can lead to malformations and inheritable diseases. So ewes, which generally mate with several males when they are in heat, could have their own strategy for preventing inbreeding, says Rodolfo Ungerfeld at the University of the Republic in Uruguay. To test this, he and his colleagues first ranked male hierarchy among eight rams by placing two of them with a ewe in heat to see which one stood closest to her for the longest time. Domestically raised sheep usually show dominance by subtle body language instead of violent fighting. Then they put the rams in pairs of one dominant and one subordinate male and tied them up at opposite corners of a large pen. They let the ewes loose in the pen, one at a time while they were in heat, until all 28 ewes had chosen between the rams. The researchers found that the ewes spent more time with the subordinate ram – on average it was three times longer, says Ungerfeld. Ewes also mated with the subordinate rams twice as often as the dominant ones. And a quarter of the ewes refused to approach the dominant ram at all. The findings make sense for a species in which sperm from different males compete for the female’s eggs in the reproductive tract, says Andrew McLean at the University of Melbourne in Australia. Ewes seeking out subordinate males to mate with ensure genetic diversity in their flock.