10-31-20 Great fox-spider rediscovered on MoD land in Surrey
One of Britain's most endangered spiders has been seen for the first time in a generation. The great fox-spider is listed as critically endangered and was feared extinct in the UK. It had only ever been found at three sites, in Dorset and Surrey, and had not been seen since the early 1990s. Mike Waite, who rediscovered the spiders on a Ministry of Defence (MoD) training area in Surrey, said he was "over the moon". The arachnid enthusiast initially found some unidentifiable immature spiderlings on the site, managed by the Amphibian and Reptile Conservation Trust, after "many hours of late night searching with a torch over the last two years". The discovery then led to several mature males and a female. The great fox-spider, Alopecosa fabrilis, lives on the ground and is largely nocturnal. It is one of the largest of the wolf spider, Lycosidae, family of spiders. According to the Surrey Wildlife Trust, it has excellent eyesight - with wrap-around vision provided by eight black eyes - and captures insects at speed by chasing them across sandy terrain, over gravel and rocks before pouncing. Mr Waite, of the Surrey Wildlife Trust, said: "I am naturally over the moon to have finally proved the continued existence of the great fox-spider in the UK. "Although I've always held a latent interest in spiders, as a bona-fide arachnologist, I am still a relative newbie, so am doubly pleased to have made this important contribution to our scientific knowledge." Nick Baker, naturalist, TV presenter and president of the British Arachnological Society, said the spider was "mega", adding: "It's about as handsome as a spider gets, it's big and now it's officially a member of the British fauna again."
10-31-20 How frigid lizards falling from trees revealed the reptiles’ growing cold tolerance
Some lizards can go to 5.5° C, 4 degrees colder than thought, before they can’t move any more. After the coldest night in south Florida in a decade, lizards were dropping out of palm trees, landing legs up. The scientists who raced to investigate the fallen reptiles have now found that, despite such graceless falls, some of these tropical, cold-blooded creatures are actually more resilient to cold than previously thought. The finding sheds light on how some species might respond to extreme weather events caused by human-caused climate change (SN: 12/10/19). Although climate change is expected to include gradual warming globally, scientists think that extreme events such as heat waves, cold snaps, droughts and torrential downpours could also grow in number and strength over time. The idea for the new study was born after evolutionary ecologist James Stroud received a photo of a roughly 60-centimeter-long iguana on its back on a sidewalk from a friend in Key Biscayne, an island town south of Miami. The previous night, temperatures dropped to just under 4.4° Celsius (40° Fahrenheit). “When air temperatures drop below a critical limit, lizards lose the ability to move,” says Stroud, of Washington University in St. Louis. Lizards that sleep in trees “may lose their grip.” Stunned lizards on the ground are likely easy prey for predators, he notes. Realizing that the cold snap could be used to study how future instances of extreme weather might affect such animals in the wild, Stroud and colleagues rushed to collect live specimens of as many different kinds of lizards as they could in the Miami area (SN: 8/27/20). The researchers then tested how well the six reptile species they captured tolerated cold by sticking thermometers on the animals, placing them in a large cooler of ice and observing how cold they got before becoming too stunned to right themselves after getting flipped on their backs.
10-30-20 Dogs are humans' oldest companions, DNA shows
A study of dog DNA has shown that our "best friend" in the animal world may also be our oldest one. The analysis reveals that dog domestication can be traced back 11,000 years, to the end of the last Ice Age. This confirms that dogs were domesticated before any other known species. Our canine companions were widespread across the northern hemisphere at this time, and had already split into five different types. Despite the expansion of European dogs during the colonial era, traces of these ancient indigenous breeds survive today in the Americas, Asia, Africa and Oceania. The research fills in some of the gaps in the natural history of our close animal companions. Dr Pontus Skoglund, co-author of the study and group leader of the Ancient Genomics laboratory at London's Crick Institute, told BBC News: "Dogs are really unique in being this quite strange thing if you think about it, when all people were still hunter gatherers, they domesticate what is really a wild carnivore - wolves are pretty frightening in many parts of the world. "The question of why did people do that? How did that come about? That's what we're ultimately interested in." To some extent, dog genetic patterns mirror human ones, because people took their animal companions with them when they moved. But there were also important differences. For example, early European dogs were initially diverse, appearing to originate from two very distinct populations, one related to Near Eastern dogs and another to Siberian dogs. But at some point, perhaps after the onset of the Bronze Age, a single dog lineage spread widely and replaced all other dog populations on the continent. This pattern has no counterpart in the genetic patterns of people from Europe. Anders Bergström, lead author and post-doctoral researcher at the Crick, said: "If we look back more than four or five thousand years ago, we can see that Europe was a very diverse place when it came to dogs. Although the European dogs we see today come in such an extraordinary array of shapes and forms, genetically they derive from only a very narrow subset of the diversity that used to exist." An international team analysed the whole genomes (the full complement of DNA in the nuclei of biological cells) of 27 ancient dog remains associated with a variety of archaeological cultures. They compared these to each other and to modern dogs. The results reveal that breeds like the Rhodesian Ridgeback in southern Africa and the Chihuahua and Xoloitzcuintli in Mexico retain genetic traces of ancient indigenous dogs from the region.
10-30-20 How octopuses ‘taste’ things by touching
Unique nerve cells found in the animal’s suckers can detect prey’s defense chemicals. Each of these eight supple yet powerful limbs can explore the seafloor in search of prey, snatching crabs from hiding spots without direction from the octopus’ brain. But how each arm can tell what it’s grasping has remained a mystery. Now, researchers have identified specialized cells not seen in other animals that allow octopuses to “taste” with their arms. Embedded in the suckers, these cells enable the arms to do double duty of touch and taste by detecting chemicals produced by many aquatic creatures. This may help an arm quickly distinguish food from rocks or poisonous prey, Harvard University molecular biologist Nicholas Bellono and his colleagues report online October 29 in Cell. The findings provide another clue about the unique evolutionary path octopuses have taken toward intelligence. Instead of being concentrated in the brain, two-thirds of the nerve cells in an octopus are distributed among the arms, allowing the flexible appendages to operate semi-independently (SN: 4/16/15).“There was a huge gap in knowledge of how octopus [arms] actually collect information about their environment,” says Tamar Gutnick, a neurobiologist who studies octopuses at Hebrew University of Jerusalem who was not involved in the study. “We’ve known that [octopuses] taste by touch, but knowing it and understanding how it’s actually working is a very different thing.” Working out the specifics of how arms sense and process information is crucial for understanding octopus intelligence, she says. “It’s really exciting to see someone taking a comprehensive look at the cell types involved,” and how they work. Bellono and his colleagues weren’t sure what they would find when they took a close look at the arms of a California two-spot octopus (Octopus bimaculoides). Detailed imaging identified what appeared to be sensory cells, some with fine branched endings, at the surface of suckers. The researchers isolated the cells and tested their response to a variety of stimuli, such as fish extract and pressure. One class of cells turned out to be similar to those that detect touch in a variety of animals. But the cells that responded to fish extract contained receptors, proteins that detect specific stimuli, unlike any seen in other animals.
10-30-20 Ogre-faced spiders catch insects out of the air using sound instead of sight
The hunters listen to both high and low frequencies but only low ones trigger an attack. Some spiders wait for prey to come and tickle their web. But the ogre-faced spider (Deinopis spinosa) uses its sense of hearing to take its web to the prey. Hanging upside down, the spider weaves a rectangular web between its legs. When an insect flies behind the dangling arachnid, the spider swings backward, casting the web toward the prey. This behind-the-back hunting technique is one clue that the spiders can hear an unexpectedly wide range of sounds, researchers report online October 29 in Current Biology. “A couple years ago, we didn’t really have a great idea that spiders could hear,” says Jay Stafstrom, a sensory ecologist at Cornell University. But now, he and his colleagues have looked at several spider species, and most can hear using specialized organs on their legs, he says. That includes jumping spiders, which respond to low frequencies (SN: 10/15/16). Surprisingly, ogre-faced spiders can also hear fairly high frequencies, Stafstrom says. Stafstrom and colleagues inserted microelectrodes into the brains of 13 ogre-faced spiders, and then played tones of varying frequencies from a speaker while monitoring the spiders’ auditory nerve cell activity. Spikes of activity revealed that the spiders can sense airborne sounds between 100 and 10,000 hertz, though not at every frequency, the team found. (Humans generally hear between 20 Hz and 20,000 Hz.). Nerve cells in amputated spider legs — where the slit sensilla, the organ that responds to sound vibrations, is located — also responded to the wide range of frequencies. This finding confirms that the spiders hear with their legs, the researchers say. The team wondered how the spiders would respond to hearing sounds of varying frequencies in the wild. So the scientists took their speaker to part of the spiders’ natural range in Gainesville, Fla., and found 25 of the dangling hunters waiting for prey in the dark. Of those, 13 reacted to frequencies of 150, 400 or 750 Hz. And each reacted in the same way — with a blind, backward strike.
10-29-20 Octopuses taste their food when they touch it with their arms
Octopuses can taste their prey before eating it by using their arms to “lick” it, which researchers say adds to evidence that the cephalopods’ eight appendages are analogous to tongues with “hands” and “brains”. Octopus arms are lined with suckers that include cells for neural processing of touch and taste signals. These allow them to determine if an animal is good to eat or is toxic, says Nicholas Bellono at Harvard University. That is particularly useful since octopuses tend to “blindly” hunt, sticking their limbs into holes and crevices to find hidden prey. Bellono and his colleagues studied the sucker cells of California two-spot octopuses (Octopus bimaculoides) microscopically and at a molecular level, finding that some respond to touch and others to the “taste” of chemicals in the water, with branched endings typical of sensory cells. They then used electrophysiology, which measures cells’ electrical activity, to test how sensitive the suckers’ taste and touch receptors were to different kinds of flavours and odours, respectively. The scientists determined that the receptors reacted to water-soluble chemicals, like bitter chloroquine, as well as to chemicals that don’t dissolve well in water, such as those emitted by toxic prey, says Bellono. Many marine animals, including octopuses, have olfactory organs that probably detect water-soluble chemicals and possibly some poorly soluble ones. However, this “underwater smelling” is usually thought to occur over distance in the water, like the way noses function over distance in the air. Poorly soluble molecules require close range for detection, which is made easier by direct contact, similar to how tongues work. Octopuses do actually possess a tongue-like organ in their mouths called the radula, which cuts and scrapes prey, especially shellfish. Yet it doesn’t seem capable of taste. The radula acts “more like teeth”, says Bellono. So far, the taste/touch receptors “seem to be specific to the suckers”, says Bellono.
10-29-20 Spider listens with its legs to grab flying insects out of the air
Some species of spider can grab prey out of the air at night apparently without seeing it, and now we know how. An analysis of one such spider shows it uses its legs to pick up the sound of flying insects, before throwing a net-like web over the unsuspecting animal. The ogre-faced net-casting spider (Deinopis spinosa), native to the southern US and parts of the Caribbean and South America, is a “Jekyll and Hyde”-like creature, says Ronald Hoy at Cornell University, New York. By day it uses camouflage to disguise itself as a stick, but at night it transforms into a stealthy hunter. Dangling upside down from its simple web, the spider dives forward and casts a pre-spun net, held between its four front legs, over prey passing below, says Jay Stafstrom, also at Cornell. “We already know they use their large eyes to see the prey underneath them because when we temporarily blinded them, they couldn’t catch anything below,” says Stafstrom. But Stafstrom noticed that the spiders could also perform backflips to catch insects flying above them, even though these insects were probably outside the spiders’ field of vision. Stafstrom, Hoy and their colleagues suspected that the spiders used auditory cues instead. Specifically, they wondered if a little-known organ on spider legs, simply called “the metatarsal organ”, might detect sound. The researchers tested the animals’ reactions to recorded sounds resembling flying insects. Then they tested isolated spider legs alone for nerve responses to these sounds. They found that the spiders flipped backwards to cast their nets when they heard recordings that resemble flying insect sounds, and their isolated legs showed nerve reactions to a wide range of frequencies, from 100 to 10,000 hertz. “People are always wondering if there are aliens out there somewhere, but these spiders are just one example of the many aliens already living among us,” says Hoy. With bodies up to 25 millimetres in length, net-casting spiders are relatively harmless to humans. “I’ve only been bitten once,” says Stafstrom, who hand collects hundreds for his experiments before releasing most back into the wild. “It was in my hand for 10 minutes before it finally bit, and the bite only itched for a few minutes,” he says, adding that he hasn’t noted any superpowers as a result of the bite… so far.
10-28-20 Great Barrier Reef: Scientists find reef taller than Empire State Building
An enormous coral reef has been found at the northern tip of Australia's Great Barrier Reef, the first such discovery in 120 years, scientists say. At 500m (1,640ft) high, the reef is taller than New York's Empire State Building and the Petronas Twin Towers in Kuala Lumpur, Malaysia. Scientists on a 12-month mission found the structure, detached from the Great Barrier Reef off Cape York, last week. They were conducting 3D mapping of the sea floor in the area. A team aboard a research vessel owned by the Schmidt Ocean Institute (SOI), a non-profit group based in California, used an underwater robot to explore the reef. Known as SuBastian, the robot live-streamed video of the discovery on Sunday and posted it to YouTube. "To find a new half-a-kilometre tall reef in the offshore Cape York area of the well-recognised Great Barrier Reef shows how mysterious the world is just beyond our coastline," said SOI executive director Dr Jyotika Virmani. "This powerful combination of mapping data and underwater imagery will be used to understand this new reef and its role within the incredible Great Barrier Reef World Heritage Area." The Great Barrier Reef, the world's largest coral reef, is home to more than 1,500 species of fish, 411 species of hard corals and dozens of other species. Stretching over 2,300km (1,400 miles), the reef was designated a World Heritage site in 1981 for its "enormous scientific and intrinsic importance". But in recent years, it has been vastly damaged by warmer seas which have killed off coral, dispersed other marine life and sped up growth of algae and other contaminants. A study published earlier this month found the Great Barrier Reef had lost more than half of its corals since 1995 due to warmer seas driven by climate change.
10-28-20 The secret weapon in the war between pet cats and wildlife
To stop cats killing billions of birds and small mammals every year, we must enlist the help of people who love them, which means getting inside the minds of cat owners. ARIE TROUWBORST wasn’t expecting death threats when he published his paper on cats last November. An environmental law specialist at Tilburg University in the Netherlands, Trouwborst and Han Somsen, also at Tilburg University, had argued that cat owners across the European Union could be prosecuted under existing law for allowing their pets to hunt. “I routinely address controversial topics like wolf management and trophy hunting, but they all pale when compared to the vicious reactions this received,” he says. It is the latest episode in the ongoing “cat wars”. From New Zealand and Australia to the US and Europe, cat owners and conservationists are pitted against each other as a growing body of research finds cats guilty of killing wildlife and squeezing out native rivals. One headline-grabbing report, for example, estimated that free-ranging domestic cats kill at least 1.3 billion birds and 6.3 billion small mammals each year in the US alone. Another study found that pet cats in the Netherlands kill almost twice as many animals as their feral counterparts. Emotions are running high, and the angrier conservationists become, the more cat owners dig in. But there could be a better way. “I get quite sick of the conflict focus of some conservation biologists,” says Wayne Linklater at California State University, Sacramento. “The solutions lie with the people who care most about cats, not with the people who don’t care about them.” To that end, he and a few other social scientists are studying cat owners themselves to find out what would motivate them to change their – and their cats’ – behaviour. Nobody doubts that cats kill wildlife: it is in their nature to hunt (see “Are cats really domesticated?“). Yet even experts can’t agree on how significant the problem is. The UK’s Royal Society for the Protection of Birds, for instance, says there is evidence that cats probably prioritise weak or sickly birds that would have died anyway. What is clear is the scale of the issue: cats are humanity’s second most popular pet, with 373 million kept worldwide. If their hunting is to be reduced, wildlife advocates need to persuade cat owners to curb their furry companions’ pursuit of prey.
10-28-20 Suckerfish use fast-flowing water to surf across swimming whales' skin
Cameras attached to blue whales have inadvertently revealed new information about the behaviour of remora fish that hitch a ride on larger marine animals. Among other things, the footage shows that remoras move around much more than was thought, skimming along just above the skin of the whales to minimise drag. “No one else has looked to see what remoras are doing before,” says Brooke Flammang at the New Jersey Institute of Technology. There are eight species of remora fish. Each fish has a suction disc that it uses to cling to larger animals such as whales. The disc is on the on the top of the remora’s head, so it clings upside down to sharks, mantas and rays. The remoras let go when they see a chance to feed, grabbing the food and then reattaching. They also eat skin parasites on their hosts. This lifestyle makes them difficult to study. But at a conference in 2015, Flammang saw Jeremy Goldbogen at Stanford University, California, present videos obtained by attaching cameras to blue whales with suckers. He joked that he had inadvertently captured hundreds of hours of remora footage – exactly what Flammang wanted. “We were happy to have all these photobombing remoras,” she says. Her team’s analysis of the footage shows that remoras’ favourite spots on blue whales are behind the blowhole, behind the small dorsal fin and around the pectoral. A supercomputer analysis of fluid flow around blue whales confirmed that the remoras prefer these places because there is much less drag, making it easier for them to stay attached. Yet their suction discs are strong enough for them to cling on in places where drag is much higher, the team calculated. Indeed, the videos show they do sometimes attach to places such as the tail flukes where drag is very high.
10-27-20 Endangered possums find refuge in back gardens in Western Australia
In Western Australian residential neighborhoods, critically endangered marsupials have made themselves at home in private gardens. These urban environments act as a much-needed refuge, as their habitats have been reduced by human activity and natural predators. Western ringtail possums (Pseudocheirus occidentalis) are nocturnal, cat-sized creatures that live in trees and shrubs and eat leaves and fruit. They once ranged over much of south-western Australia, but habitat loss and predation by invasive red foxes have dramatically reduced their range to three small enclaves. These last remaining pockets overlap with the urban areas of Busselton, Manjimup and Albany in Western Australia. The possums frequently turn up in back gardens in these towns, dining on roses and the leaves and fruit from trees. “We wanted to know if the habitat within gardens is sufficient for these animals to live exclusively in these areas, or whether they are still dependent on some natural habitat to survive,” says Bronte Van Helden at the University of Western Australia in Albany. She and her team targeted 16 private gardens in Albany, catching possums by exploiting their sweet tooth – they baited traps with almond meal soaked in strawberry essence. The researchers captured 20 possums and fitted them with radio-transmitter collars before releasing them. For the next three months, the team tracked signals from the collars to work out where the animals were moving and how much they were using the gardens versus nearby bushland. Surprisingly, none of the possums ever left the private gardens. They hopped between multiple gardens, feeding primarily on non-native plants like avocado trees, which made up the bulk of the garden flora. Van Helden says the results suggest that “gardens may contain sufficient resources to support wildlife” like these possums, and that such areas shouldn’t be overlooked as valuable habitat.
10-26-20 Fantastic beasts in the real world and where to find them
There's a real danger we'll get a Section 3A incident in Central London this December. Muggles are being invited to see a parade of fantastic beasts at the Natural History Museum (NHM). Erumpents, snifflers, murtlaps, occamies - you're invited to purchase tickets to see some of these magical creatures, but an obliviate spell will ensure you remember absolutely nothing after the event. Which would be a great shame because the NHM is promising its new exhibition, Fantastic Beasts: The Wonder of Nature, will be one of the best it's ever staged. The show has been two years in the planning. It's a tie-up with the BBC and Warner Brothers, who brought author JK Rowlings' Harry Potter books - and their Fantastic Beasts spinoffs - to the big screen. The NHM has spied an opportunity to use the interest in the hugely popular wizarding chronicles to tell some stories of it own about the real world and conservation. "There was a very obvious parallel for us," says Lorraine Cornish, the NHM's head conservator and science lead on The Wonder of Nature. "Consider Newt Scamander, the lead character in Fantastic Beasts. He's a magi-zoologist who goes around the world, recording and understanding all these amazing animals, but also trying to protect them. And we thought that was a great message, in terms of what we're also trying to do here at the Natural History Museum. So, the parallel is obvious; we're just going to show it to you through a different lens," she tells BBC News. The exhibition puts 90 specimens from the museum's world famous collections next to 30 or so props from the Potter/Beasts movies. Interactive and immersive displays will essentially compare and contrast the different animals - the real from the imagined. For example, there's a fictional creature that Rowling invented called a demiguise which can make itself invisible. This is an opening to talk about the different ways many animals in the real world use camouflage. It's not magic, but it's still amazing.
10-25-20 'Murder hornet': First nest found in US eradicated with vacuum hose
The first nest of Asian giant hornets found in the US has successfully been destroyed by scientists. The nest, in the state of Washington, was found by putting tracker devices on the hornets and it was sucked out of a tree using a vacuum hose. The invasive species insects, known as "murder hornets", have a powerful sting and can spit venom. They target honeybees, which pollinate crops, and can destroy a colony in just a matter of hours. The nest in Washington was found when entomologists, scientists that study insects, used dental floss to tie tracking devices to three hornets. The nest of around 200 insects was then discovered in the city of Blaine close to the Canadian border. On Saturday, a crew of scientists wearing protective suits vacuumed the insects from the tree, which will now be cut down to remove any further nests. Asian giant hornets are the among the world's largest wasps - the queens can reach over 5cm (2in) long. Their venomous sting can penetrate humans' protective clothing but the number of people they kill each year is low - about 40 annually in Asia, according to the Smithsonian museum in Washington D.C. Normally their natural habitat is in areas of Asia from China to Japan, but in 2019 there were several sightings of single "murder hornets" in North America. A nest was destroyed in Vancouver Island in Canada in December last year. Globally, conservationists are deeply concerned about falling insect populations. But it can be permissible to kill some insects if they are an invasive species - one that is not native to an area and preys on other insects there. Honeybees are under threat due to loss of food after habitat destruction, pesticides, and disease. When an Asian giant hornet enters a honeybee colony, it begins a "slaughter phase" in which it kills bee after bee and can destroy the colony in a few hours.
10-23-20 Why bat scientists are socially distancing from their subjects
Biologist Winifred Frick argues for precautions to shield North American bats from the coronavirus. There’s nothing Winifred Frick likes better than crawling through guano-filled caves and coming face-to-face with bats. As chief scientist of Bat Conservation International, she is on a mission to promote understanding of bats and protect imperiled species from extinction. For months, though, Frick has avoided research that would put her within spitting distance of bats. Her only projects to persist through the pandemic have been conducted from afar, like using acoustic monitors to eavesdrop on the animals’ squeaks and swooshes. In an era of COVID-19, that “hands-off” approach and other precautions are crucial to protect both bats and people, Frick, a biologist at the University of California, Santa Cruz, and over two dozen other scientists argue online September 3 in PLOS Pathogens. Why the call to action? SARS-CoV-2, the virus that causes COVID-19, likely originated in bats in China (SN: 3/26/20). But neither it nor other coronaviruses belonging to the same genus — Betacoronavirus — have been detected in the more than 40 bat species in North America, although the animals do harbor other types of coronaviruses. Scientists are not worried about catching SARS-CoV-2 from these bats. They’re afraid of giving it to the bats — not an impossibility, the authors argue, given that the United States leads the world in infections, with nearly 8 million as of October 16. “We can’t tell bats to socially distance,” Frick says. “We want to reduce the chance that there’s any pathogen transfer across animals, full stop.” The goal is to prevent viral “spillover.” Human-to-bat transmission isn’t an unheard-of scenario. People are likely to blame for introducing Pseudogymnoascus destructans, the fungus that causes white nose syndrome, to North American bats. The disease has killed millions of bats throughout the United States and Canada since it was first detected in 2006 (SN: 3/31/16).
10-23-20 Cats cost Australia A$6 billion a year by spreading diseases
. Diseases transmitted by cats cost the Australian economy more than A$6 billion (£3.3 billion) annually through their impact on human health and livestock production. Sarah Legge at Australian National University in Canberra and her colleagues have analysed the economic impact of cat scratch disease, in which a scratch or bite can cause an infection of the bacterium Bartonella henselae, and toxoplasmosis, a parasitic disease. The researchers estimate that these diseases and others spread by cats to humans cost the Australian economy $6.06 billion annually in medical care, insurance, social support and lost productivity. Toxoplasmosis also affects animals, causing miscarriages in sheep and goats. Another parasitic disease that spreads through cats, sarcocystosis, causes cysts to form in sheep meat, which reduces the amount that can be sold. The researchers estimate that the two parasitic diseases result in annual costs to livestock production of about $11.7 million. Toxoplasmosis is a result of an infection with the parasite Toxoplasma gondii, which cats can catch when they prey on infected birds, mice or other small animals. The parasite reproduces inside cats, and the disease probably wouldn’t exist in Australia if cats hadn’t been introduced by the British in 1788. Infected cats release the T. gondii oocysts – an egg-like form of the parasite – in their faeces, which people can then accidentally ingest, for example while gardening. People can also ingest the oocysts by eating raw or undercooked meat that is infected. The parasite enters the body, often the brain, and remains there indefinitely. The researchers used estimates of toxoplasmosis prevalence – about 30 per cent of the global population – as well as the frequency of its health impacts. They combined government and other research statistics on medical costs and employment data.
10-21-20 Near-uncrushable beetle's exoskeleton could inspire tough structures
The diabolical ironclad beetle is so tough that engineers are hoping to copy features of its exoskeleton to design stronger and more robust structures. “You can run these things over with a car and they don’t die,” says David Kisailus at the University of California, Irvine. “We took a Toyota, like a sedan, and drove over them and they survived. That was kind of surprising.” To investigate what makes these creatures virtually uncrushable, Kisailus and his colleagues performed compression tests on the beetle’s exoskeleton, while analysing it under a microscope and by CT scan. The researchers discovered ellipsoidal beam-like structures surrounding the beetle’s exoskeleton, which combine with tiny interlocking blades that form joints between the two segments of the beetle’s exoskeletal forewings, enabling the beetle to endure extreme compression. Kisailus hopes that understanding the diabolical ironclad beetle’s uniquely tough structure will help inform the design of stronger components for use in building lighter aircraft, resulting in planes that consume less fuel and emit less carbon dioxide. “No need to reinvent the wheel, just figure out what nature’s done,” he says. As a test, he and his team joined together a carbon-based material with a piece of metal, mimicking the joint structure of the beetle’s exoskeleton. They found it was about twice as tough as a standard joint commonly used to connect similar parts when building aircraft. “In engineering applications, commonly used joints between materials often fracture at their thinnest regions due to stress concentration,” says Po-Yu Chen at National Tsing Hua University in Taiwan. The beetle’s tiny interlocking blades provide a new way to improve toughness and prevent fracturing at these types of joints, he says. Why this species of beetle evolved such a tough exoskeleton in the first place is a mystery. The beetle spends a lot of its time squeezing under rocks and into bark, says Kisailus, and is predated by rodents, birds and lizards. “Maybe it was just exposed to a more dangerous environment than other beetles.”
10-22-20 The diabolical ironclad beetle can survive getting run over by a car. Here’s how
Microstructures in the beetle’s armor make it nearly impossible to squish. The diabolical ironclad beetle is like a tiny tank on six legs. This insect’s rugged exoskeleton is so tough that the beetle can survive getting run over by cars, and many would-be predators don’t stand a chance of cracking one open. Phloeodes diabolicus is basically nature’s jawbreaker. Analyses of microscope images, 3-D printed models and computer simulations of the beetle’s armor have now revealed the secrets to its strength. Tightly interlocked and impact-absorbing structures that connect pieces of the beetle’s exoskeleton help it survive enormous crushing forces, researchers report in the Oct. 22 Nature. Those features could inspire new, sturdier designs for things such as body armor, buildings, bridges and vehicles. The diabolical ironclad beetle, which dwells in desert regions of western North America, has a distinctly hard-to-squish shape. “Unlike a stink beetle, or a Namibian beetle, which is more rounded … it’s low to the ground [and] it’s flat on top,” says David Kisailus, a materials scientist at the University of California, Irvine. In compression experiments, Kisailus and colleagues found that the beetle could withstand around 39,000 times its own body weight. That would be like a person shouldering a stack of about 40 M1 Abrams battle tanks. Within the diabolical ironclad beetle’s own tanklike physique, two key microscopic features help it withstand crushing forces. The first is a series of connections between the top and bottom halves of the exoskeleton. “You can imagine the beetle’s exoskeleton almost like two halves of a clamshell sitting on top of each other,” Kisailus says. Ridges along the outer edges of the top and bottom latch together.
10-22-20 Secrets of the 'uncrushable' beetle revealed
The diabolical ironclad beetle is one tough critter, as its name might suggest. Equipped with super-tough body armour, the insect can survive being stamped on or even run over by a car. Now scientists have investigated the secrets of how the beetle can withstand forces up to 39,000 times its body weight. And the findings could give clues to building tougher materials for use in construction and aeronautics. The research, published in the journal Nature, could lead to "tough, impact- and crush-resistant materials", says a team led by David Kisailus of the University of California, Irvine. The diabolical ironclad beetle (Phloeodes diabolicus) is found mainly in the US and Mexico, where it lives under the bark of trees or beneath rocks. The beetle has one of the toughest exoskeletons of any known insect. Early insect collectors became aware of this when trying to mount specimens to boards with standard steel pins. Their pins bent and snapped, and they had to resort to a drill to penetrate the tough outer casing. The beetle, having lost the ability to fly away from danger, has evolved crush-resistant forewings (known as elytra), to survive being pecked to death by hungry birds. The researchers used microscopy, spectroscopy and mechanical testing, to identify a series of interlocked jigsaw-shaped joints within the exoskeleton, which allow the beetle to withstand forces of up to 149 Newtons (approximately 39,000 times the creature's body weight). To test the potential of this type of structure as a way of joining different materials, such as plastics and metal, the scientists made a series of joints from metal and composites based on those seen in the beetle. They say their designs enhanced the strength and toughness of the materials. Other natural materials, such as bones, teeth and shells, have long served as inspiration for scientists seeking to develop new materials. Many have exceptional mechanical performance, as well as strength, toughness and the ability to self-heal.
10-21-20 Some male fish use their tails to fan rivals’ sperm away from eggs
To boost their chances of fertilising a nest-load of eggs, some male fish use their tailfin to fan away the sperm deposited by rivals. Scientists have previously determined that penis shapes can help male animals remove a rival’s sperm from the female reproductive tract. However, the new study is the first to discover that even among animals that fertilise eggs outside the body, males have strategies to remove rivals’ sperm and increase their paternity chances. Takeshi Takegaki of Nagasaki University in Japan and his colleagues studied the behaviour of 12 nest-holding male dusky frillgoby fish (Bathygobius fuscus), common in the Indo-Pacific Ocean, when faced with rival sperm in their nests. Like most bony fish, dusky frillgobies reproduce by spawning, meaning males ejaculate semen into the water to fertilise eggs. Nest-holding males are fish that occupy a hole between rocks and then encourage females to lay eggs inside, which the male then fertilises and protects from other males. So-called sneaker males – which are smaller but with larger testicles – literally sneak into nests to ejaculate over just-laid eggs and then swim away. Nest-holding males “aggressively chase” sneaker males away from their rock holes, says Takegaki, and then fan their tails at the nest entrance after the intruder leaves as if they’re “sweeping out” the rival semen. Takegaki’s team injected equivalent amounts of either sea water or sneaker male semen into nest-holding males’ rock holes in laboratory aquariums. They found that the nest-holding males swished their tails about 30 times more when they detected the presence of manually injected sneaker sperm compared with sea water. The fish probably pick up chemical signals from the rival sperm which influence their behaviour, he says. This active tail swishing led, on average, to an 87 per cent drop in sperm concentration in the nest, he says. While that effectively contributes to the removal of rival sperm from the nest, tail swishing has a major drawback: it also removes the nest-holding male’s sperm. To compensate, the fish then produce more of their own sperm in the nest.
10-21-20 Naked mole-rats invade neighboring colonies and steal babies
When the burrow is king, it may pay to be part of a huge, aggressive army. Naked mole-rats — with their subterranean societies made up of a single breeding pair and an army of workers — seem like mammals trying their hardest to live like insects. Nearly 300 of the bald, bucktoothed, nearly blind rodents can scoot along a colony’s labyrinth of tunnels. New research suggests there’s brute power in those numbers: Like ants or termites, the mole-rats go to battle with rival colonies to conquer their lands. Wild naked mole-rats (Heterocephalus glaber) will invade nearby colonies to expand their territory, sometimes abducting pups to incorporate them into their own ranks, researchers report September 28 in the Journal of Zoology. This behavior may put smaller, less cohesive colonies at a disadvantage, potentially supporting the evolution of bigger colonies. Researchers stumbled across this phenomenon by accident while monitoring naked mole-rat colonies in Kenya’s Meru National Park. The team was studying the social structure of this extreme form of group living among mammals (SN: 6/20/06). Over more than a decade, the team trapped and marked thousands of mole-rats from dozens of colonies by either implanting small radio-frequency transponder chips under their skin, or clipping their toes. One day in 1994, while marking mole-rats in a new colony, researchers were surprised to find in its tunnels mole-rats from a neighboring colony that had already been marked. The queen in the new colony had wounds on her face from the ravages of battle. It looked like a war was playing out down in the soil. “Naked mole-rats are better known for their cooperation within colonies than competition between colonies,” notes Stan Braude, a biologist at Washington University in St. Louis. But over the course of the long-term study, Braude and his colleagues found that 26 colonies expanded their tunnels by digging into burrow systems occupied by neighboring colonies. In half of these cases, the invaded colony fled to a different arm of their tunnel system as the invaders expanded their territory. In the other half of cases, the invaded colony was entirely displaced, and the original mole-rats were never encountered there again. In four incursions, researchers caught invading mole-rats in the act, and in three of those, the bigger colony was doing the invading.
10-20-20 Eating jellyfish: Why scientists are talking up a 'perfect food'
Australian researchers recently found that over 90 species of endangered fish are caught legally by industrial fisheries globally. In the wake of the study, scientists have again suggested eating more jellyfish as a sustainable option. Why? Marine biologist Lisa-ann Gershwin says there are a few reasons.
10-20-20 Fire ants build little syphons out of sand to feed without drowning
To escape a watery death, the insects construct relatively sophisticated structures on the fly. The threat of death is no obstacle for some hungry fire ants. To escape drowning while feeding on sugary water, black imported fire ants built syphons out of sand that moved the water to a safer spot. A range of animals, including birds, dolphins, primates and even ants, use objects as tools (SN: 12/30/19; SN: 6/25/20; SN: 6/24/19). Ants often employ debris or sand grains to carry food. But this is the first time that the insects have been observed adjusting their tool use to build relatively complex structures in response to a problem, researchers report October 7 in Functional Ecology. In the wild, black imported fire ants (Solenopsis richteri) typically eat honeydew produced by aphids. In the lab, entomologist Jian Chen of the U.S. Department of Agriculture’s Agricultural Research Service in Stoneville, Miss., and colleagues provided the ants with containers of sugary water. The insects have a hard, water-repellent outer covering called a cuticle, and can typically float on a liquid — and sure enough, the insects floated and fed without a problem. The researchers then reduced the water’s surface tension with a surfactant to make it more difficult for the ants to float. While some ants drowned, most stopped entering the containers and instead used grains of sand placed nearby to build structures leading from the inside of a container to outside of it. Those structures acted like syphons. Within five minutes of building one, nearly half of the water was drawn out through the sand pathway, allowing the ants to feed safely. “The fact that ants are building little syphons is new and interesting,” says Valerie Banschbach of Gustavus Adolphus College in Saint Peter, Minn., who was not involved in the study. The insects’ “flexibility to act in a creative way responding to a situation suggests that they have higher cognitive abilities than what is traditionally believed.”
10-20-20 A rope bridge restored a highway through the trees for endangered gibbons
Simple artificial structures could help reconnect forests fragmented by human activities. With acrobatic leaps, Hainan gibbons can cross a great gully carved by a 2014 landslide in the forest on China’s Hainan Island. But when a palm frond caught by the vaulting apes to steady their landing started to sag, researchers rushed to provide a safer route across. Though slow to adopt it, the gibbons increasingly traveled a bridge made of two ropes that was installed across the 15-meter gap, researchers report October 15 in Scientific Reports. The finding suggests that such tethers could also help connect once-intact forests that have been fragmented by human activities and aid conservation efforts of these and other canopy dwellers. “Fragmentation is becoming an increasing problem,” says Tremaine Gregory, a conservation biologist at the Smithsonian’s National Zoo and Conservation Biology Institute in Washington, D.C., who wasn’t involved in the study. “It’s probably going to be, along with climate change, one of the biggest challenges for biodiversity in decades.” The landslide damaged an arboreal highway, a preferred route through the trees that the apes use to traverse the rainforest. Hainan gibbons (Nomascus hainanus) are almost strictly arboreal, and forest fragmentation can divide the already critically endangered primates (SN: 8/6/15) into smaller breeding populations, says Bosco Chan, a conservation biologist at the Kadoorie Farm and Botanic Garden in Hong Kong. That can lead to inbreeding or local groups dying out. Only about 30 individuals remain of this species, all living in a nature reserve on Hainan Island. For the group of nine gibbons studied, the researchers didn’t want the animals to get hurt crossing the gap. Enter the rope bridge. It took months for the gibbons to catch on, but about 176 days after the bridge’s installation, camera traps captured the gibbons taking to the ropes. “I was very excited when [the gibbons] first started using it,” Chan says.
10-19-20 Heating deltamethrin may help it kill pesticide-resistant mosquitoes
The insecticide is used to control pests that spread life-threatening diseases like malaria. A few minutes in the microwave made a common insecticide about 10 times more lethal to mosquitoes in lab experiments. The toxin deltamethrin is used around the world in home sprays and bed nets to curb the spread of mosquito-borne diseases like malaria — which kills over 400,000 people each year, according to the World Health Organization. But “mosquitoes the world over are showing resistance to deltamethrin and [similar] compounds,” says Bart Kahr, a crystallographer at New York University who has helped develop a more potent form of deltamethrin by heating it. This form of deltamethrin may stand a better chance of killing insecticide-resistant pests, Kahr and colleagues report online October 12 in the Proceedings of the National Academy of Sciences. Malaria has been essentially eradicated in the United States, but more effective pesticides could be a boon for regions like sub-Saharan Africa, where the disease is a major public health problem. Kahr’s team increased the potency of commercial deltamethrin dust spray simply by melting a vial of it — either by heating it to 150° Celsius in an oil bath for five minutes or by popping it in a 700-watt microwave for the same amount of time. While the microscopic deltamethrin crystals in the original spray have a haphazard structure, which looks like a jumble of misaligned flakes, the melted deltamethrin crystals solidified into starburst shapes when they cooled to room temperature. Chemical bonds between deltamethrin molecules in the starburst-shaped crystals are not as strong as those in the original microcrystal structure. “The molecules are intrinsically less happy, or settled, in the arrangement,” Kahr says. So, when a mosquito lands on a dusting of starburst-shaped crystals, it should be easier for deltamethrin molecules to be absorbed into the insect’s body via its feet.
10-15-20 Artificial rope bridges help stop rare primates jumping to extinction
With a population that fell to just 25 individuals a few years ago, every Hainan gibbon counts. So when a 2014 landslide on China’s Hainan Island forced the last surviving members of the world’s most endangered primate species to make death-defying leaps across a gap in the forest canopy, conservationists lent them a hand by stringing ropes between the trees. The plan worked. Although the gibbons (Nomascus hainanus) took six months to get used to the idea, most of them eventually used the rope bridges to cross the 15-metre gap, either swinging along, crawling upside down or sometimes balancing like tightrope walkers. Only the larger males didn’t need the ropes. Gibbons are very reluctant to come down to the ground, so after the landslide, this group reached fruit trees by flinging themselves across the large gap above a rocky floor as much as 30 metres below. Although the researchers saw no accidents, they thought a fall would be deadly. “It was pretty scary to watch – my heart just popped out of my throat,” says Bosco Chan at the Kadoorie Farm & Botanic Garden in Hong Kong. Mothers had to make the leap with their baby clinging on. “If the infant-carrying mother falls, that would have been two down out of 25,” says Chan. Today there are thought to be about 30 gibbons on the island. Trees in the dangerous area have since regrown, but Chan says rope bridges are proving useful in helping other primates cross gaps between fragmented habitats.
10-15-20 Conservation: Bridge of hope for world's rarest primate
Swinging through the treetops comes naturally for gibbons. But that's tricky if a landslide has torn a huge gap in the forest, making it difficult to roam far and wide, to find food or meet a date. For the rarest primate in the world, there's now a temporary solution: a rope bridge reconnecting the trees. And scientists have filmed the ape, a type of gibbon, climbing or swinging across in seconds. Some used the ropes as a handrail, others swung by their arms and the most daring walked the tightrope. The primate lives only in the forests of China's Hainan island. All nine in the group mastered the rope bridge, save one adult male, which made a mighty jump from one tree to another, sometimes accompanied by athletic teenage companions. Conservation scientists say the 18-metre-long structure could be an essential lifeline for the endangered species, while the forests are restored to their former glory. A small number of primates, including the orangutan, have been seen to use artificial rope bridges. But this is the first time the Hainan Gibbon has learnt the ropes. The gibbon is the most critically endangered primate on Earth, with only about 30 left. A conservation programme run by the Kadoorie Farm and Botanic Garden in Hong Kong is trying to rescue the species from extinction. Dr Bosco Chan says the rope bridge should help boost numbers as part of various conservation efforts. "When we started work at the reserve, in 2003, we could only find two groups with a total of 13 individuals were left in the entire world," he told BBC News. "The gibbon population has gradually recovered, with a third and fourth family group formed in 2011 and 2015, respectively. "At the beginning of 2020, we confirmed the formation of the fifth group, and the world population has bounced back to over 30 individuals. It shows the species is slowly recovering, and we should have hope." Reforestation should be the priority in preventing extinction of the species, he added. "We need to make sure we control poaching effectively, expand lowland forest which is the optimal habitat for gibbons, and keep monitoring the gibbon groups to predict and prevent any threats."
10-14-20 Ivory Coast’s elephant populations are now in catastrophic decline
Ivory Coast, named for its elephants, once had one of the largest elephant populations in West Africa. But now the country’s elephant numbers are in rapid decline. Sery Gonedelé Bi at the University Félix Houphouët-Boigny in Abidjan, Ivory Coast, and his colleagues surveyed 25 protected forest areas across the country between 2011 and 2017. They also analysed media reports and records of conflicts between humans and elephants. Based on their results, the researchers estimate that there are only 225 forest elephants left in Ivory Coast – a decline of 86 per cent since a survey conducted in 1994. Estimates suggest that about a century ago, the population of forest elephants numbered between 3000 and 5000, says Gonedelé. Based on dung counts, the team confirmed the presence of elephants in only four of the 25 protected areas they surveyed. Habitat degradation is a likely factor that has driven the decline in population. Despite its protected status, the team found that of the 360,000 hectares the 25 forests cover, 71 per cent has been cleared. Much of the cleared land has been transformed into plantations, mostly for cocoa, says Gonedelé. More than half of the 25 areas have been completely converted to farms and human settlements. Previous analysis has shown that an estimated 265,000 hectares of forest are cleared in the country every year – the highest deforestation rate in sub-Saharan Africa. The researchers found that the four protected areas with remaining elephant populations received more protection from conservation staff than the other 21, which don’t receive any tangible wildlife management. “We need to reinforce protections where elephants still live,” says Gonedelé. The researchers believe that without immediate action to safeguard still-existing populations, such as ranger patrolling and law enforcement, forest elephants will go extinct in Ivory Coast.
10-14-20 Pugs and bulldogs have more eye and foot problems than other dogs
Pugs and bulldogs are known for having breathing issues due to being bred to have flat faces. A new analysis of veterinary records shows they are also more likely than dogs with longer snouts to develop painful eye inflammation and foot infections. Dan O’Neill at the Royal Veterinary College, UK, and his colleagues devised the first comprehensive database of British dog health records so that they could analyse the health risks to different breeds. The team analysed a random sample of more than 22,000 dogs. About 4000 came from 34 breeds of flat-faced dogs, such as Cavalier King Charles Spaniels, shih-tzus, pugs, bulldogs and chihuahuas. “A study like this has never been done before because there has never been access to a single database on the general UK dog population before,” says O’Neill. The database suggests that about 19 per cent of the British dog population is flat-faced. The team found that these dogs are 1.3 times more likely to be diagnosed with at least one serious health condition in a given year than other types. They were also far more likely to experience certain conditions. For example, flat-faced dogs were 8.4 times more likely to have corneal ulcerations and 1.7 times more likely to have foot infections. “This study is useful as it confirms what much research has suggested about flat-faced dog breeds but goes into greater detail about the type of disorder prevalent in those breeds,” says Catherine Douglas at Newcastle University, UK, who wasn’t involved in the study. The specific increased health risks could be explained by the traits the dogs have been bred for, says O’Neill. “The skulls of flat-faced dogs have been selectively bred to be flatter which also means that the socket for the eyeball becomes shallower,” he says. “It means that their eyes are more exposed to drying out and to injury.” (Webmaster's comment: This breeding of animals for flat faces should be crime!)
10-14-20 How Venus flytraps store short-term ‘memories’ of prey
Calcium concentrations in leaf cells signal when the carnivorous plants should snap shut. A Venus flytrap’s short-term “memory” can last about 30 seconds. If an insect taps the plant’s sensitive hairs only once, the trap remains still. But if the insect taps again within about half a minute, the carnivorous plant’s leaves snap shut, ensnaring its prey. How Venus flytraps (Dionaea muscipula) remember that initial touch has been a mystery. A new study reveals that the plants do so using calcium, researchers report online October 5 in Nature Plants. Scientists know that some plants have a type of long-term memory, says study coauthor Mitsuyasu Hasebe, a biologist at the National Institute for Basic Biology in Okazaki, Japan. One example is vernalization, whereby plants remember long periods of winter cold as a signal to flower in the spring. But short-term memory is more enigmatic, and “this is the first direct evidence of the involvement of calcium,” Hasebe says. Even though the carnivorous plant, famous for its jawlike leaves, has no brain or nervous system, it can apparently count to five and distinguish between live prey and things like rain, which could inadvertently trigger its leaves to snap shut, wasting energy (SN: 1/24/16). Previous research suggested that calcium plays a role in this process, but with the help of genetic engineering, Hasebe and colleagues were able to actually see calcium in action. The researchers added genes to the Venus flytraps that produce a protein, which glows green when exposed to calcium. When the team tapped one of the trap’s sensory hairs, the base of that hair began glowing, and then the glow spread through the leaf before beginning to fade. When the researchers touched the hair a second time — or touched a different hair on the leaf — within about 30 seconds, the trap’s leaves lit up even brighter than before, and the plant quickly snapped shut.
10-14-20 Leafcutter ants choose architecturally sound building materials
Ants that construct turrets for their nests choose what to build them with in an architecturally sound way, even when given unfamiliar materials. South American leafcutter ants (Acromyrmex fracticornis) carry plant clippings into underground chambers where they use them to cultivate fungus for food. To promote fungal growth, they build thatch-like turrets that keep rainwater from flooding their nests and that create the correct humidity level. In their natural environment, the ants select thick wooden sticks for the base of the turrets, overlapping them like a log cabin, and lightweight grass for the top, then plaster the interior with clay pellets. The whole process takes three days. “They try to keep [the nest] at about 25°C for the fungus and then really high humidity,” says Daniela Römer at the University of Würzburg, Germany. “Putting plant fibres on top prevents against humidity loss.” To test how the ants choose their building materials, Römer and her colleagues replaced their regular choice of twigs and fresh grass with slivers of processed smooth wood and dry grass. They found that the insects still made the same decisions with these new materials, selecting for thickness at the base and lighter vegetation, which promotes humidity, at the top. This illustrates how relatively simple animals can use social organisation to create complex structures, says Römer. “They just react to what is right in front of them,” she says. “They’re not thinking of what they’re building or how it’s supposed to look. But by organising their behaviour in the whole colony, reacting to each other’s cues and cues from their environment, they actually manage to build very complex structures that you wouldn’t expect such simple animals to be able to do.”
10-14-20 Tardigrades survive deadly radiation by glowing in the dark
A tiny tardigrade can survive intense ultraviolet radiation for an hour by glowing in the dark. “It acts like a shield,” says Sandeep Eswarappa at the Indian Institute of Science in Bangalore. Tardigrades, also known as water bears, are animals around 1 millimetre long. They are famous for being able to withstand extreme conditions that would kill most organisms, such as being completely dried out. Studying moss at their institute’s campus, Eswarappa and his colleagues found what may be a new species of tardigrade, though they don’t yet have enough information to formally describe it. For now, they are calling it Paramacrobiotus BLR, short for Bangalore. “We found this particular tardigrade in many places, especially in places that are well lit with sunlight,” says Eswarappa. The researchers transferred some of the animals to their laboratory and began to study them. Their first experiment involved exposing the animals to a germicidal ultraviolet lamp. A control animal, a worm called Caenorhabditis elegans, died within 5 minutes, but Paramacrobiotus BLR survived for an hour. “The next step happened serendipitously,” says Eswarappa. While looking at how the tardigrades might survive the UV light, he left a tube of them near a UV source and noticed that the tube started glowing. Further experiments revealed that the tardigrades contain a fluorescent chemical. “It is absorbing the UV light and emitting harmless visible light in the blue range,” says Eswarappa. The team was able to transfer the fluorescent chemical to another tardigrade, Hypsibius exemplaris, and to C. elegans, both of which are sensitive to ultraviolet radiation. This protected them from 15 minutes of UV exposure. The team doesn’t yet know exactly what makes up the fluorescent shield, as simple methods for identifying the chemicals haven’t yielded clear results. “It is not a simple compound,” says Eswarappa.
10-14-20 Glowing blue helps shield this tardigrade from harmful ultraviolet light
Fluorescence may allow water bears to survive in especially sunny regions. When blasted with ultraviolet radiation, a newly discovered species of tardigrade protects itself by glowing blue. Tardigrades, microscopic animals also known as water bears or moss piglets, are nature’s ultimate survivor. They’re game for temperatures below –270° Celsius and up to 150° C and can withstand the vacuum of space, and some are especially resistant to harmful UV radiation (SN: 7/14/17). One species shields itself from that UV radiation with glowing pigments, a new study suggests. It’s the first experimental evidence of fluorescent molecules protecting animals from radiation, researchers report October 14 in Biology Letters. “Tardigrades’ tolerance for stress is extraordinary,” says Sandeep Eswarappa, a biochemist at the Indian Institute of Science in Bangalore, India, “but the mechanisms behind their resistance is not known in most [species].” He and his colleagues investigated these mechanisms in a new tardigrade species from the genus Paramacrobiotus that the scientists identified and then grew in the lab after plucking specimens from a mossy wall on campus. Eswarappa found that like many other tardigrades, these Paramacrobiotus are resistant to ultraviolet radiation. After sitting under a germicidal UV lamp for 15 minutes — ample time to kill most microbes and give humans a skin lesion — all Paramacrobiotus specimens survived, seemingly unfazed by the ordeal. The secret of how these water bears persisted eluded Eswarappa and his team until one day when the researchers happened to view a tube of the ground-up tardigrades in a UV transilluminator, used to visualize fluorescence in the lab. To the team’s surprise, the tube glowed blue. “It was our mini-eureka moment,” Eswarappa says.
10-13-20 A glowing zebrafish wins the 2020 Nikon Small World photography contest
The annual competition brings some of Earth’s smallest marvels to light. While seeking answers to scientific questions, it’s worth sometimes taking a step back to appreciate the world’s exquisiteness. For developmental biologists Daniel Castranova, Bakary Samasa and Brant Weinstein, some of that delicate beauty is inside a zebrafish. While working in Weinstein’s lab at the National Institutes of Health in Bethesda, Md., Castranova and Samasa snapped a stunning photograph of a young zebrafish, illuminating never-before-seen parts of its lymphatic system. The photo comes from research that sought to determine whether zebrafish have lymphatic vessels inside their skulls. The lymphatic system helps clear toxins and waste from the body, and previously researchers thought only mammals had such structures close to the brain. But zebrafish have those vessels too, Castranova and colleagues report in preliminary research posted in May at bioRxiv.org. The team used fish that had been genetically modified to have lymphatic vessels that fluoresce orange under certain conditions, with skeletons and scales that glow blue. Because fish are easier than mammals to raise and image in the lab, Castranova says, the finding could help scientists more easily study the role of the brain’s lymphatic system in neurological diseases like brain cancer or Alzheimer’s. After taking the photo — a composite of 350 images taken with a confocal microscope — on a busy work day, “I never even looked at the picture for a couple of weeks,” Castranova says. “And then when I looked at it at some point post-data processing, I was like ‘Wow.’” Even if it took Castranova a bit to appreciate what he had in hand, judges for the 2020 Nikon Small World photomicroscopy competition realized that it was a winner. The photo snagged first place in the 46th annual contest. The results were announced October 13.
10-13-20 Covid: Why bats are not to blame, say scientists
Every now and then, Dr Mathieu Bourgarel seeks permission from the village elders to visit the sacred caves, bringing a gift to appease the spirits. Donning mask, overalls, and three layers of gloves, he descends into the darkness, climbing down rope ladders and squeezing through the narrow chambers of caves. The tell-tale odour of bats is everywhere, their excrement deposited in layers on the floor, like wading through fresh snow. Occasionally, a bat is startled from sleep, wings brushing by as it takes flight. People in this part of Zimbabwe call bats "winged dragons", "flying rats" or simply the "evil ones". Like elsewhere in the world, the flying mammals are much misunderstood. For this wildlife ecologist, they're beautiful and incredible creatures. "They are fascinating," he says. "People are frightened of something they don't know." Dr Bourgarel is a virus hunter for the French research institute, Cirad. Working with colleagues at the University of Zimbabwe he goes into the bat caves to collect samples and droppings from bats. Back at the lab, the scientists extract and sequence the genetic material of bat viruses. They have already discovered different coronaviruses, including one in the same family as Sars and Sars-CoV-2. The research is part of a worldwide effort to investigate the diversity and genetic make-up of the viruses that bats carry, providing the tools to react quickly, should people start to get sick. "The local population frequently visits these bats' habitat, in order to collect guano to use as fertiliser for their crops. It is therefore essential to know the pathogens carried by the bats, because they could be transmitted to humans," says Dr Elizabeth Gori of the University of Zimbabwe. Bat experts have launched a campaign, Don't Blame Bats, to dispel unfounded fears and myths about bats, which are threatening conservation. They say bats are some of the most misunderstood and undervalued animals on the planet. Long the target of disdain, persecution and cultural prejudice, they have been blamed for a host of evils visited upon humans. And fears and myths about bats have only intensified in the time of Covid.
10-13-20 Pufferfish may be carving mysterious ‘crop circles’ near Australia
The only other known rings are fish nests found 5,500 kilometers away, in Japan. Japan’s white-spotted pufferfish are renowned for producing complex, ringed patterns in the sand. Now, 5,500 kilometers away in Australia, scientists have discovered what appear to be dozens more of these creations. While conducting a marine life survey out on Australia’s North West Shelf near subsea gas infrastructure with an autonomous underwater vehicle, marine ecologist Todd Bond spotted a striking pattern on the seafloor, more than 100 meters deep. “Immediately, I knew what it was,” recounts Bond, of the University of Western Australia in Perth. Bond and his colleagues continued the survey, ultimately finding nearly two dozen more. Until now, these undersea “crop circles” were found only off the coast of Japan. First spotted in the 1990s, it took two decades to solve the mystery of what created them. In 2011, scientists found the sculptors — the diminutive males of what was then a new species of Torquigener pufferfish. The patterns are nests, meticulously plowed over the course of days and decorated with shells to entice females to lay their eggs in the center. While there’s no video confirmation that pufferfish are building the nests in Australia, the structures are nearly identical to those in Japan, even sharing a similar number of ridges, Bond and his colleagues report in the November 2020 Journal of Fish Biology. And when a colleague deployed an underwater video system in the area, the contraption luckily landed almost directly atop a circle and captured footage of a small pufferfish fleeing the formation. The Australian circles lie in much deeper waters than Japan’s — 130 meters or more deep compared with about 30 meters deep in Japan. Australian pufferfish known in the area typically inhabit more shallow waters, raising questions about the identity of the species responsible.
10-12-20 ‘Great Adaptations’ unravels mysteries of amazing animal abilities
Tales of unusual animals — and unusual science — make for an entertaining read. Neurobiologist Kenneth Catania’s passion for scrutinizing odd animal adaptations all started with a creature with a 22-point star on its face. Catania first saw a star-nosed mole (Condylura cristata) in a children’s book. Later as a 10-year-old, he found a dead one near a stream close to his home in Columbia, Md. From then on, he kept his eyes peeled for more. He had to wait until he was in college, when he landed a research position that required him to trap star-nosed moles in Pennsylvania’s wetlands. At the time, no one knew what that unique nose was good for, and he wanted to figure it out. In Great Adaptations, Catania describes his pursuit of the mystery behind the mole’s wiggly star-shaped appendage (it helps the subterranean animal sense prey without using sight) as well as a slew of other animal tricks. The account of his adventures as a biological sleuth provides a detailed look at curiosities such as how “hangry” water shrews execute the fastest documented predatory attack by a mammal and how cockroaches resist becoming zombies during parasitoid wasp attacks (SN: 10/31/18). “It’s part of human nature to be intrigued by mysteries, but the mystery only gets us to the door,” he writes. “You never know what you might find on the other side.” In search of answers, Catania has set up some odd, but amusing, experiments. To film wasps attacking cockroaches, he built a set fit for a horror flick, by filling a tiny kitchen with warning signs and a plastic human skull for the wasp to store its zombified victim in. Keeping with the horror theme, he also stripped the paint off decorative severed zombie arms and offered the plastic limbs to electric eels (Electrophorus electricus) to show that the animals leap out of the water as an attack strategy (SN: 6/9/16).
10-10-20 'Real and imminent' extinction risk to whales
More than 350 scientists and conservationists from 40 countries have signed a letter calling for global action to protect whales, dolphins and porpoises from extinction. They say more than half of all species are of conservation concern, with two on the "knife-edge" of extinction. Lack of action over polluted and over-exploited seas means that many will be declared extinct within our lifetimes, the letter says. Even large iconic whales are not safe. "Let this be a historic moment when realising that whales are in danger sparks a powerful wave of action from everyone: regulators, scientists, politicians and the public to save our oceans," said Mark Simmonds. The visiting research fellow at the University of Bristol, UK, and senior marine scientist with Humane Society International, has coordinated the letter, which has been signed by experts across the world. "Save the whales" was a familiar green slogan in the 1970s and 1980s, part of a movement that helped bring an end to commercial whaling. While stricken populations in most parts of the world have had a chance to recover from organised hunting, they are now facing myriad threats from human actions, including plastic pollution, loss of habitat and prey, climate change and collisions with ships. By far the biggest threat is becoming accidently captured in fishing equipment and nets, which kills an estimated 300,000 whales, dolphins and porpoises a year. Hundreds of scientists have expressed the same concern - that we are moving closer to a number of preventable extinctions. And unless we act now, future generations will be denied the chance to experience these intelligent social and inspiring creatures. They point to the decline of the North Atlantic right whale, of which only a few hundred individuals remain, and the vaquita, a porpoise found in the Gulf of California, which may be down to the last 10 of its kind.
10-9-20 Naked mole rats invade neighbouring colonies and kidnap their babies
Naked mole rats go to war. The sociable little mammals have been observed invading neighbouring populations and even kidnapping newborn pups, who become workers in the conquering colony. The rats (Heterocephalus glaber) are one of a handful of mammal species that are eusocial: they live in large underground colonies in which most members are sterile workers and only one individual, the queen, reproduces. They have been compared with eusocial insects like honeybees. Stan Braude at Washington University in St Louis, Missouri, and his colleagues made crucial observations of the rats attacking their neighbours in the early 1990s, but didn’t have the genetic technology to confirm what they suspected had happened at the time. The researchers were tracking colonies of naked mole rats in Meru National Park, Kenya, and noticed 26 examples of colonies expanding their territory into burrows previously occupied by other colonies. As part of their study, the team repeatedly captured entire colonies, marked each animal, then returned them to their burrows. This allowed the researchers to track individual naked mole rats over successive years. In May 1994, they began capturing two neighbouring colonies and noticed that the queen of one had wounds on her face, suggesting that the second colony had attacked. They returned the animals to their burrows, but the following year they found two pups from the attacked colony living as workers in the other one. For years, Braude suspected he had simply made a mistake. “We just didn’t have the tools to make sure that I hadn’t totally screwed up,” he says. Now, genetic analyses of tissue samples from the original animals have confirmed that the pups really had ended up in a different colony. It seems the pups became completely integrated into their new home, although it isn’t clear whether they ever had the opportunity to reproduce.
10-8-20 Rat that uses whiskers to hunt underwater prey is really four species
An elusive type of wading rat armed with super-powered whiskers is actually four separate species, researchers have found. African wading rats, formerly the single species Colomys goslingi, are truly unusual rodents. They are one of the only semi-aquatic rodents in Africa, striding into streams on long, stilt-like feet. There, they drape long whiskers on the water’s surface, sensing the vibrations of their prey: aquatic insects, tadpoles and small fish moving underwater. “It was known all the way from Liberia to Kenya, which is an insanely wide distribution for a really small animal,” says Tom Giarla at Siena College in Loudonville, New York. This cross-continental range stood out to Giarla and his colleagues, who wondered if the territory was actually inhabited by a series of hidden species. The team examined dozens of wading rats in museum collections and captured specimens across their wild range. They carefully compared the rodents’ physical feature, and analysed samples of their DNA. The team also compared the rats with the similar Ethiopian amphibious rat (Nilopegamys plumbeus), which was only collected once in 1927 and may be extinct. Two of the wading rat populations in the Congo basin and West Africa were distinct, unrecognised species. The team named them Colomys lumumbai and Colomys wologizi, respectively. The team also discovered that a Colomys goslingi subspecies in Cameroon was a full species, and that the wading rat’s closest genetic relative is the mysterious Nilopegamys. Giarla says he is most interested in learning more about how the new species interact with their environments. Understanding the rats’ habitat requirements is crucial because their rainforests are threatened by deforestation, mining and political strife.
10-7-20 Vine grows its own greenhouses to help fruit develop in autumn
A volunteer nature guide in Japan has discovered that a type of vine creates mini-greenhouses to warm its developing fruits. He has now co-authored a scientific paper describing the finding. In the autumn of 2008, Nobuyuki Nagaoka noticed that some leaves on an annual vine called Schizopepon bryoniifolius had expanded and overlapped with each other to form enclosures. Inside these were many developing fruits. He noticed the same unusual structures forming again in the following autumns. Nagaoka eventually contacted Shoko Sakai at Kyoto University, whose team has now studied these vines on Mount Gassan in the Dewa mountains in Yamagata prefecture. The researchers suspected that the enclosures acted as mini-greenhouses, so they monitored the temperatures in intact ones and in places where the leaves were removed. They found the temperatures in intact enclosures were up to 5°C higher at noon on sunny days, and also varied less. They think the enclosures also protect developing fruits from frost damage, but they haven’t shown this. Far fewer fruits grew to more than a centimetre in diameter when the enclosures were removed. Plants at higher, colder sites also grew thicker enclosures. “The results suggest that enclosures allow the plant to produce seeds under the cold weather the plant encounters at the end of its life,” the researchers write. S. bryoniifolius isn’t the only plant that makes its own greenhouses. A species of rhubarb that grows high up in the Himalayas, Rheum nobile, forms hollow columns up to 2 metres high made of overlapping, pale-yellow leaves. It can be up to 10°C warmer inside these columns than outside. Some other plants, such as Eriophyton wallichii, have woolly leaves to insulate themselves, while the petals of buttercups focus heat on the centre of the flower. A few plants, such as the eastern skunk cabbage, can even warm themselves by burning sugar to generate heat.
10-7-20 This rare bird is male on one side and female on the other
Male rose-breasted grosbeaks have some red-pink feathers while females’ are yellow and brown. In Rector, Pa., researchers have spotted one strange bird. This rose-breasted grosbeak has a pink breast spot and a pink “wing pit” and black feathers on its right wing — telltale shades of males. But on its left side, the songbird displays yellow and brown plumage, hues typical of females. Annie Lindsay had been out capturing and banding birds with identification tags with her colleagues at Powdermill Nature Reserve in Rector on September 24 when a teammate hailed her on her walkie-talkie to alert her of the bird’s discovery. Lindsay, who is banding program manager at Powdermill, immediately knew what she was looking at: a half-male, half-female creature known as a gynandromorph. “It was spectacular. This bird is in its nonbreeding [plumage], so in the spring when it’s in its breeding plumage, it’s going to be even more starkly male, female,” Lindsay says. The bird’s colors will become even more vibrant, and “the line between the male and female side will be even more obvious.” Such birds are rare. Lindsay has seen only one other similar, but less striking, bird 15 years ago, she says. Gynandromorphs are found in many species of birds, insects and crustaceans such as crabs and lobsters. This bird is likely the result of an unusual event when two sperm fertilize an egg that has two nuclei instead of one. The egg can then develop male sex chromosomes on one side and female sex chromosomes on the other, ultimately leading to a bird with a testis and other male characteristics on one half of its body and an ovary and other female qualities on the other half. Unlike hermaphrodites, which also have genitals of both sexes, gynandromorphs are completely male on one side of the body and female on the other.
10-6-20 Your dog’s brain doesn’t care about your face
Unlike people, canines don’t seem to have neural systems that are extra sensitive to visages. Lots of dog owners love to gaze at their pups’ faces. But that fascination may be a one-way street, at least in the brain. Dogs’ brains aren’t especially impressed by faces, either those of other dogs, or of people, a new study suggests. People’s brains are exquisitely tuned into faces, and the wealth of information that expressions can convey. Whether other animals’ brains are as vigilant to faces is an open question. Researchers in Hungary and Mexico used brain-scanning technology on 20 pet dogs to measure responses to faces. The dogs were trained to lie still in a sphynx position inside an MRI tube, resting their head on a chin rest while watching a screen. The scientists played four types of two-second video clips for the dogs to view: the front or back of a human head, and the front or back of a dog head. Thirty human volunteers in MRI machines saw the same short videos. As many earlier studies have found, faces were captivating for people. When shown a face — either human or dog — a large swath of these people’s visual systems became active. These brain regions were quieter when the people saw the backs of heads. The vision-processing parts of the dogs’ brains, however, didn’t seem to care about faces, the researchers report October 5 in the Journal of Neuroscience. No brain areas had greater activity when viewing a face compared with the back of a head. Instead, areas of the dogs’ visual systems were more tuned to whether the video featured a dog or a human. Still, the study measured brain responses — not behavior. The results don’t mean that dogs themselves don’t see, or don’t care, about faces. Other studies have shown that canines can recognize people’s facial cues. (Webmaster's comment: A dog's major sense for understanding the world is smell.)
10-6-20 A drop of blood can reveal how old wild elephants are
The age of African or Asian elephants can be now estimated with high accuracy by analysing patterns of chemical changes on the DNA of blood cells. The same approach works for many other animals, including beluga whales, and could help conservation efforts. “I’m an ageing researcher, and elephants are very interesting because they have very long lives and are cancer resistant,” says Steve Horvath at the University of California, Los Angeles. “But it is very difficult to estimate their age.” Female elephants can live up to 75 years, and males up to 65 years. Wild elephants’ ages are often roughly estimated based on their sex and size. There have been attempts to develop more scientific methods based on shoulder height, tusk size and even the diameter of droppings. The most accurate method involves examining the teeth, but this cannot be done with living wild elephants. In 2011, Horvath developed a way of estimating the biological age of people based on looking at patterns of methylation on the DNA inside cells. These patterns change over time as gene activity changes. “It still surprises me that this is even possible,” says Horvath. This approach can also accurately age many animals including dogs, pigs and mice, Horvath has shown, though for Tasmanian devils it isn’t proving as accurate so far. His team has now developed “ageing clocks” for elephants based on 140 blood samples from elephants at zoos in the US and Canada whose age is known. The method is 97 per cent accurate, says Horvath. “I think this is a fabulous technique,” says Phyllis Lee at the University of Stirling in the UK, who studies wild elephants and helped refine the tooth-based method. But she thinks it will be of more use to biologists studying ageing than conservationists. “Knowing the age structure of populations is fantastic, but not if you have to take blood from the animals,” she says.
10-5-20 Israel moves to ban 'immoral' animal fur trade
Israel says it intends to ban the buying and selling of animal furs, apart from in specially approved cases, making it the first country to do so. Announcing plans for new regulations, environmental protection minister Gila Gamliel said the use of skin and fur for the fashion industry was "immoral". Her ministry said future permits would only be considered under certain, limited criteria. Animal rights group Peta said it "applauded" Israel's move. Until now, only a handful of cities - in the US, and São Paulo in Brazil - have banned the sale of all animal fur. At present, anyone in Israel wishing to buy or sell fur must apply for a permit, but under the new rules this will only be allowed in cases of "scientific research, education or for instruction and for religious purposes or tradition". The exemption is likely to apply to Israel's sizeable ultra-Orthodox community, among whom many of the men wear large round fur hats called shtreimels, believed to have originated as a custom in Eastern Europe. "The fur industry causes the killing of hundreds of millions of animals around the world, and involves indescribable cruelty and suffering," said Ms Gamliel. "Utilising the skin and fur of wildlife for the fashion industry is immoral." Elisa Allen, the director of the People for the Ethical Treatment of Animals (Peta), praised Israel "for recognising that the trade in coats, pom-poms, and other frivolous fashion items made from wild animals' fur offends the values held by all decent citizens". Anyone found breaking the law in Israel will face a fine of up to $22,000 (18,500 euros; £17,000) or a year in prison.
10-5-20 Tasmanian Devils reintroduced into Australian wild
Tasmanian devils have been reintroduced into the wild in mainland Australia for the first time in 3,000 years. Conservation groups released 26 of the mammals into a large sanctuary in Barrington Tops, north of Sydney. It's thought that packs of dingoes helped eradicate them on the mainland. There are still some on the island state of Tasmania but their numbers have dwindled over the past two decades. The Tasmanian devil, classified as endangered, gets its name from its high-pitch squeal and is renowned for fighting over access to animal carcases, which it grinds with the bone-crushing force of its jaws. Animal experts say they pose no threat to humans or agriculture. Conservation group Aussie Ark worked with other animal groups to release the Tasmanian devils into the 1,000-acre fenced sanctuary. The animals have been placed in the sanctuary to help keep their chances of survival high. They have no supplied food, water or shelter. The first group of 15 were released in March. After the animals showed signs of thriving in their environment, a further 11 were released in September. Young, healthy Tasmanian devils were selected in the hope they would be ready for breeding season, set to begin in February. "They're free. They're out there," Tim Faulkner, president of Aussie Ark, told National Geographic. "We've got some basic means of keeping an eye on them. But essentially, now it's over to the devils to do what they do." Another 40 are set to be released into the sanctuary over the next two years. Over time, Aussie Ark hopes to release some Tasmanian devils into unfenced areas. It's estimated that there are fewer than 25,000 devils in the wild in Tasmania. During the 1990s, there were as many as 150,000 but the animal population was hit by a deadly mouth cancer that drastically cut numbers.
10-5-20 Kamchatka: Pollution killing sea life in Russian far east
Many dead sea creatures have washed up on beaches in Kamchatka, in Russia's far east, in what is being treated as a major marine pollution incident. Video and photos posted on social media show dead octopuses, seals and other dead sea life, as well as a large stretch of discoloured ocean. Local residents who used the Pacific beaches complained of vomiting, fever, rashes and swollen eyelids. Initial analysis detected oil products and phenol in the water. The environmental group Greenpeace has called it "an ecological disaster". Kamchatka is one of Russia's remotest regions, famous for its pristine nature and active volcanoes. "We began to see that something was wrong with the water because after an ordinary surf you come out feeling good, but this time it felt like we had burned eyes, we couldn't even see straight," local surfer Rasul Gadzhiev said. Another surfer, using the Instagram handle yola_la, wrote that "the seabed is all dead. Octopuses, fish, starfish and sea urchins - they're all dead from Cape Nalychev to Avacha Bay, and that's more than 40km (25 miles)". She said surfers in the area had first complained of feeling ill three weeks ago. The Kamchatka administration website says Russia's emergencies ministry is investigating. Specialists are collecting samples from the beaches and rivers and using drones to help in their analysis. The website says there were reports in late September that the waters on Khalaktyr beach had changed colour and had a peculiar smell. It confirmed that dead octopuses, seals and other sea creatures had been washed up. Kamchatka governor Vladimir Solodov said volunteers were also helping the authorities in their investigation. "We cannot claim that the ocean is dying wholesale here, but now it's really important for us to assess the scale of this," he said.
10-4-20 What happens to all of the dead leaves?
A crunchy brown leaf may seem like an ending. But the food webs it supplies can be far more expansive than the ones it nourished when it was young, green, and in its prime. In a cool afternoon, I enter a shaded path leading into a small nature preserve near my home in southern Maine. I tread slowly beneath the pines, eager to explore beyond the confines of my pantry and home office after weeks of COVID-19 stay-at-home orders. As I crunch over dead leaves into the shadows, I'm pulled farther in by the sound of rushing water, and soon a wide stream emerges to the left. I have never visited this seven-acre patch of woods before, so I soak up its newness. The moist twigs lit by dappled sunlight, the large clumps of dead leaves damming up eddies: They relieve some of the weight of the pandemic. All this debris may look like a mess, but it's actually a sign of health. A mucky stream breeds new life; a sterile stream breeds nothing. I stare at one brown leaf, hanging and wagging in the current. Where's it headed? What new life will it brew? What will come of this dead leaf? For me, it's an idle thought. For Jane Marks, it's all in a day's work. As a biologist at Northern Arizona University in Flagstaff who studies leaf litter, she's been tromping through streams and contemplating messy debris for decades and, when we speak over the phone from our home offices, she tells me that it never gets old. "There are always little surprises," she says. Dead leaves, Marks explains, provide a primary food base for life all the way up the food chain in and around streams, from the fungi and bacteria that initially colonize the leaves, and the insects that chew them, down to the birds and fish that eat those insects, and so on. Different organisms prefer different types of leaves, so the greater the variety of trees along a stream bank, the greater variety of life they support. These "brown" or "dead" food webs can be far more expansive than the "green" food webs a leaf nourishes when it's still alive, Marks says. A fresh leaf might feed caterpillars or beetles that in turn feed insect-gobbling carnivores, but the pool of nutrients that dead leaves release by decaying in water adds another dimension to their contribution. "Understanding what happens once it's dead," she says, "is actually as important or more important than understanding what's happening when it's alive." The nuances are many, Marks writes in an article titled Revisiting the Fates of Dead Leaves That Fall into Streams in the Annual Review of Ecology, Evolution, and Systematics. No two trees produce the same two leaves, so she is working to understand which species produce more nutritious or digestible leaves, and which groupings of trees are best suited to feed different types of aquatic ecosystems. Riparian zones — areas on land that border rivers and streams — make up only a fraction of the landmass on any given continent, but often contain an outsized dose of biodiversity that fuels the ecosystems beyond. So Marks's findings have practical applications that belie the simple wag of that brown leaf I observe on my stroll, as ecologist Amy Marcarelli explains when I call her some days later: Knowing how leaf litter breaks down helps inform efforts ranging from fisheries management to water quality improvements to large-scale river restoration projects. The research also has implications for climate science, adds Marcarelli, who studies aquatic ecosystems at Michigan Technological University. Dead leaves can release carbon dioxide into the atmosphere when they decay. Or they can trap carbon dioxide safely underground if they become buried and remain unconsumed. So understanding these "fates of dead leaves that fall into streams" — poetical phrasing borrowed from a paper published in the 1970s — "is really important," Marcarelli says.
10-3-20 This snake rips a hole in living toads’ stomachs to feast on their organs
It’s the first time that scientists have observed this behavior in the reptiles. Some snakes eat toads by politely swallowing the creatures whole. Others saw a hole in a toad’s abdomen with their teeth, shove their heads in and gorge on organs and tissues — while the amphibian is still alive. “Toads don’t have the same feelings and can’t sense pain in the same way as we can,” says Henrik Bringsøe, an amateur herpetologist who lives in Køge, Denmark. “But still, it must be the most horrible way of dying.” In a new study, published September 11 in Herpetozoa, Bringsøe and his Thailand-based colleagues document three such attacks on toads by small-banded kukri snakes (Oligodon fasciolatus). It’s the first time that researchers have observed this behavior in snakes, though animals like crows or raccoons eat some toads in a similar fashion. Small-banded kukri snakes are known to use their teeth — which resemble curved kukri knives used by Nepalese Gurkha soldiers — to tear into eggs. And like most snakes, O. fasciolatus also feed by swallowing their meals whole. The snakes may use the newly described method, the researchers say, to best evade a toxin that the Asian black-spotted toad (Duttaphrynus melanostictus) secretes from glands on its neck and back (SN: 6/19/18). One Asian black-spotted toad was already dead when the children of coauthors Winai and Maneerat Suthanthangjai — both environmental researchers at Loei Rajabhat University in Loei, Thailand — stumbled upon a snake feasting on its innards near the city. But the whole area was bloody, and the snake had clearly dragged its prey around. It was clear “that it had been a true battlefield,” Bringsøe says. Two other episodes at a nearby pond involved living Asian black-spotted toads. One fight that Winai watched lasted almost three hours, as a snake battled with the toad’s toxic defenses before finally winning. A kukri snake saws into its prey using its teeth like a steak knife, he says, “slowing cutting back and forth until it can put its head in” and eat the organs.
10-2-20 A new map shows where Asian giant hornets could thrive in the U.S.
Washington state officials are racing to find and kill ‘murder hornets’ before they can spread. The race is on to keep Asian giant hornets from spreading in the Pacific Northwest. Since 2019, 12 of the hornets — five trapped and dead, the rest photographed but escaped — have turned up in Washington state. That includes three recently reported in Whatcom County, Wash. Others have been found in British Columbia, Canada. “We’re pretty sure there’s at least one nest” somewhere near Birch Bay along the Washington coast, says Karla Salp, a spokesperson for the Washington State Department of Agriculture in Olympia. Efforts are under way to catch a live hornet, attach a radio tag and track it back to a nest, Salp says. The plan is to destroy the nest, hopefully before hornets that can start nests of their own hatch. That usually happens in mid to late October, she says. That eradication effort was already urgent thanks to the insects’ reputation: The world’s largest hornets (Vespa mandarinia) have been dubbed “murder hornets” in part for their deadly assaults on honeybees (SN: 5/29/20). Now a new study maps where the giant hornets could spread if left unchecked. Asian giant hornets thrive where it’s mild and rainy — and that makes large swaths of the Pacific Northwest prime real estate for them. Farther afield regions of the United States — including along the East Coast — could potentially support the hornets, but it’s unlikely the insects could fly that far on their own, researchers report online September 22 in the Proceedings of the National Academy of Sciences. The mapping efforts are important because “we really don’t know anything about how this species spreads,” says Chris Looney, an entomologist with Washington’s agriculture department. Details like how fast the hornets can fly and how their preference for underground nests affects their potential to spread are unknown, he explains. “That’s the kind of maddening lack of information that makes responding to this species so challenging.”
10-2-20 Cockroach species found to live like ants with workers and a queen
Cockroaches can team up. A South American species is the first cockroach known to live in group nests with workers and a queen, like honeybees or leaf-cutter ants. “All cockroaches are solitary,” says Peter Vršanský at the Slovak Academy of Sciences in Bratislava – or so everyone thought. “It’s unbelievable. It’s like discovering ants as a group.” Some animals, such as honeybees, are eusocial: not only do they live in large groups and work together to tend the young, but most individuals don’t themselves reproduce. Worker bees are sterile, for instance, and only the queen lays eggs. Vršanský’s colleagues spent 20 years looking for living specimens of the cockroach Melyroidea magnifica, which has barely been seen since it was identified in cloud forests around the Rio Bigal in Ecuador in 1912. Local conservationist Thierry Garcia at the Sumac Muyu Foundation in Ecuador finally found a nest in 2017. The cockroaches nested in bamboo or hardwood trees in groups of several hundred. They spend a lot of time inside the nests, which explains why they were so hard to find. “There was one week where not one cockroach was outside,” says Vršanský. The adult cockroaches had bright red heads and green abdomens. There were also tiny black larvae. The team found one individual that was 1.25 times larger than the others and had white wings. They have tentatively identified this as the queen, although Vršanský says they need more evidence to be sure. “We would need to prove that it is the only individual which lays eggs,” he says. But in two months of observations, they never saw the other cockroaches laying eggs, which suggests they are sterile workers. The finding highlights how little is known about cockroach behaviour, says Vršanský. “We know nearly nothing.”
10-2-20 Before migrating, some blue whales switch up the timing of their songs
The world’s largest animal goes from nighttime to daytime crooning before heading south. During the summer feeding season in high latitudes, male blue whales tend to sing at night. But shortly before migrating south to their breeding grounds, the whales switch up the timing and sing during the day, new research suggests. This is not the first time that scientists have observed whales singing at a particular time of day. But the finding appears to be the first instance of changes in these daily singing patterns throughout the yearly feeding and mating cycle, says William Oestreich, a biological oceanographer at Stanford University. In the North Pacific, blue whales (Balaenoptera musculus) spend summers off North America’s coast gorging on krill before traveling to the tropics to breed in winter. Data collected by an underwater microphone dropped into Monterey Bay in California to record the region’s soundscape for five years allowed Oestreich and his colleagues to eavesdrop on whales that visited the bay. When the team separated daytime and nighttime whale songs, it stumbled upon a surprising pattern: In the summer and early fall, most songs occurred at night, but as winter breeding season approached, singing switched mostly to the daytime. “This was a very striking signal to observe in such an enormous dataset,” says Oestreich. The instrument has been collecting audio since July 2015, relaying nearly 2 terabytes of data back to shore every month. The researchers also tagged 15 blue whales with instruments and from 2017 to 2019, recorded the whales’ movements, diving and feeding behavior, as well as their singing — nearly 4,000 songs’ worth. Whales that were feeding and hadn’t yet started migrating to the breeding grounds sang primarily at night — crooning about 10 songs per hour on average at night compared with three songs per hour in the day, or roughly three times as often. But those that had begun their southward trip sang mostly in the day, with the day-night proportions roughly reversed, the team reports October 1 in Current Biology.
10-1-20 Covid-19: Funding crisis threatens zoos' vital conservation work
Zoos' vital conservation work is being put at risk by a Covid-related funding crisis. Breeding programmes to rescue rare species may have to be cancelled, with many zoos facing the biggest cash crisis in their history. The body that represents British zoos says a government rescue package is inaccessible for most of its members. Only one zoo has claimed successfully, the BBC has learned. Zoos face huge income losses due to lockdown and reduced visitor numbers. Ultimately, this will impact on their ability to care for species which are the last of their kind on Earth, and now found only in zoos. "The extinct-in-the-wild species are absolutely dependent on human care," said Dr John Ewen of the Zoological Society of London (ZSL). "It's our decision about which way to go forward that determines extinction or recovery." Zoos are one of the largest funders of conservation work around the world, particularly large, successful zoos in Europe, North America and Australia. Dr Alexandra Zimmermann is a senior research fellow at Oxford University and former head of conservation at Chester Zoo. She told BBC News: "Zoos contribute hundreds of millions of support all over the world for conservation in the wild so if we lose a lot of that support from the effects of Covid, then that has really detrimental effects on conservation everywhere." At least 77 species of plants and animals are classified as extinct in the wild by the International Union for the Conservation of Nature (IUCN), which compiles data on endangered species. The Guam kingfisher is one such bird, disappearing in the 1980s from the island of Guam, a US territory in the western Pacific. A stowaway snake was accidently brought in on military equipment, where it wreaked havoc on the ecosystem. With no natural predator, the snake species rapidly multiplied, eventually growing to such a number that it ate most of the island's native bird species.