9-21-20 Botswana: Mystery elephant deaths caused by cyanobacteria
Toxins made by microscopic algae in water caused the previously unexplained deaths of hundreds of elephants in Botswana, wildlife officials say. Botswana is home to a third of Africa's declining elephant population. The alarm was raised when elephant carcasses were spotted in the country's Okavango Delta between May and June. Officials say a total of 330 elephants are now known to have died from ingesting cyanobacteria. Poaching has been ruled out as a cause of death. The toxic bacteria can occur naturally in standing water and sometimes grow into large blooms known as blue-green algae. The findings follow months of tests in specialist laboratories in South Africa, Canada, Zimbabwe and the US. Many of the dead elephants were found near watering holes, but until now the wildlife authorities had doubted that the bacteria were to blame because the blooms appear on the edges of ponds and elephants tend to drink from the middle. "Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths. These are bacteria found in water," the Department of Wildlife and National Parks' Principal Veterinary Officer Mmadi Reuben told a press conference on Monday. The deaths "stopped towards the end of June 2020, coinciding with the drying of [water] pans", AFP quotes him as saying. Reports in June noted that tusks had not been removed. Poaching has been ruled out as cause of death, as has anthrax poisoning, according to senior wildlife department official Cyril Taolo. But questions still remain about the deaths, Mr Reuben told reporters. "We have many questions still to be answered such as why the elephants only and why that area only. We have a number of hypotheses we are investigating." Hundreds of carcasses were spotted with the help of aerial surveys earlier this year. Dr Niall McCann, of the UK-based charity National Park Rescue, previously told the BBC that local conservationists first alerted the government in early May, after they undertook a flight over the delta. "They spotted 169 in a three-hour flight," he said. "To be able to see and count that many in a three-hour flight was extraordinary.
9-21-20 Hundreds of whales stranded off the coast of Tasmania
At least 25 whales are thought to have already died as conservationists begin a huge rescue operation at Macquarie Heads off the coast of Tasmania.The mission is due to begin early on Tuesday morning to release approximately 270 whales which have become stuck on two sand banks and a beach. This unusual event is not unprecedented in this region as a similar number of whales were stranded nearby around a decade ago.
9-19-20 Brazil's Pantanal fires: Animals 'dying of hunger and thirst'
More than 15,000 fires in Brazil's Pantanal wetlands have been causing widespread devastation this year. The basin's wildlife has paid a heavy price, suffering death and injury, hunger and thirst.
9-19-20 Cheap, innovative venom treatments could save tens of thousands of snakebite victims
New attention brings hope for people in poor, farming areas. When Nigerian physician Garba Iliyasu was 10, a venomous snake bit a family member. The man survived, but “it was quite severe,” Iliyasu recalls. “[He] was bleeding profusely.… From the nose. From the mouth. From the ear.” Since then, Iliyasu, a specialist in infectious and tropical diseases, has tended to hundreds of snakebite victims at Kaltungo General Hospital, a health care hub for the surrounding Gombe State. During the two annual peaks in snakebite cases — the spring planting and autumn harvest seasons — “we see like six, seven to 10 patients in a day, on average,” he says. The hospital has only a few dozen beds. “Most times, you see patients on the floor.” In the Western world, snakebites are a minor issue. In the United States and Europe, cases are rare and hardly ever fatal. Even in Australia — notorious for its deadly, venomous snakes — bites account for just a handful of annual deaths. But in sub-Saharan Africa, about 270,000 people are bitten every year, resulting in more than 55,000 cases of post-traumatic stress disorder, over 14,700 amputations and about 12,300 deaths, Iliyasu and colleagues estimated in Toxicon in March 2019. Add in India and other snakebite hot spots and the annual numbers rise to more than 2 million bites that need clinical treatment, according to the World Health Organization. Between 80,000 and 138,000 victims die, and about three times that number have a life–changing disability. Snakebites are “a neglected disease that affects the neglected section of the society,” Iliyasu says. The worst effects occur in mostly poor, rural communities that depend on farming and herding. Visit these places, he says, and “you will see how devastating the effect of snakebite is.” Victims are often the primary breadwinners of their households, so every death and disability contributes to the cycle of poverty.
9-17-20 Watch titan triggerfish jump out of the water to catch and eat crabs
Many land animals will dip beneath the waves to catch and eat fish, but the reverse situation can sometimes occur too, as the titan triggerfish demonstrates. The fish, which can grow to a length of 75 centimetres, will sometimes beach itself to feed on crabs walking along the shoreline. In 2018, on the Red Sea’s Mar Mar Island, Matthew Tietbohl, a coral reef ecologist at King Abdullah University of Science & Technology in Saudi Arabia, was surveying a beach for sea turtle tracks with some colleagues. The team heard loud splashing at the water’s edge. “We turned to see this triggerfish launching itself into the shallows and stranding itself,” recounts Tietbohl. It soon became clear that the fish was attempting to feed on ghost crabs that were grazing on algae-covered rocks at the water’s edge. The triggerfish would slowly stalk the crabs from the water, turning on its side and lunging out of the shallows like a crocodile. At one point, the fish successfully gripped a crab, pulling it back into the water. The determined diner was about 35 centimetres long, but titan triggerfish (Balistoides viridescens) can exceed twice that length, and were already infamous among divers, sometimes rushing and biting divers with crushing teeth in a territorial defence of their nests. Titan triggerfish are clever, says Tietbohl, using a suite of foraging techniques, including flipping over spiky urchins to expose their vulnerable undersides. “So this beaching behaviour does fit the titan triggerfish’s reputation as a fish that seeks out food in many ways,” says Tietbohl. Still, the observations were surprising, because none of the handful of fish species that strand themselves to eat land-based prey are closely related to triggerfish. In fact, only a small proportion of these are saltwater fish.
9-17-20 Training bees to prefer certain flower scents boosts seed production
It is possible to train honeybees to prefer certain flowers. Feeding them food with a sunflower scent makes them more likely to visit sunflowers, boosting seed production by up to 60 per cent. Many crops require insect pollination. In some parts of the world, beehives are routinely trucked from farm to farm to maximise pollination levels during the brief flowering periods. When the hives are moved, it can take time for the bees to start foraging on the new crop around them “By conditioning bees inside the nest, it’s possible to reduce the delay to begin foraging in a new surrounding,” says Walter Farina at the University of Buenos Aires, Argentina. His team had previously shown that honeybees remember the food scents exchanged within colonies. To see if these memories can be exploited to influence behaviour, the researchers first developed a simplified version of the scent of sunflowers, containing just a few key chemicals. They then gave some hives a sugar solution with this scent added, to train the bees to associate the scent with a reward. When these hives were moved near to a field of sunflowers, foragers from the hives started doing waggle dances directing other bees to the sunflower field within an hour, and just a few hours later 84 per cent of all waggle dances were directing other bees to the sunflowers. By contrast, in hives that had been given sugar without the sunflower scent added, it was 5 hours before any waggle dances directed bees to the sunflowers. The researchers also put harmless coloured powder at the entrance to hives so that exiting bees would be colour-marked. They then caught bees visiting sunflowers and checked their colour. This confirmed that more bees from the hives fed the scented food were visiting sunflowers.
9-16-20 Mass deaths of migratory birds reported in New Mexico
Biologists in New Mexico have sounded the alarm after thousands of song birds were found dead in recent days. New Mexico State University Professor Martha Desmond told local media that the reason for the mass die off is a mystery but could be tied to smoke from wildfires, or the recent cold weather. The number of birds that have died may now be in the "millions", she said. Scientists have reported North American bird populations have declined massively in recent years. State biologists have asked people to report sightings of dead birds for further research to be conducted. Some birds - including migratory warblers, swallows and bluebirds - were seen acting strangely before their deaths, according to witnesses. "It's devastating. I don't think I've ever seen anything this horrible in my life," Prof Desmond, who works for the university's department of fish, wildlife, and conservation ecology, told KRQE-TV. "When you're there, you know, picking them up off the ground and seeing the extent of it and then looking at all these carcasses come in," she continued. Neighbouring south-west states such as Colorado, Arizona, and Texas have also reported increased numbers of bird deaths. Smoke from wildfires is thought to have affected the birds lungs, or forced them to change migratory routes. Recent snows in Colorado could also be a culprit, Prof Desmond said, adding that more will not be known until the animals carcasses can be studied. Meanwhile, the US Forest Service in the Santa Fe National Forest have appealed for public help. In a tweet on Friday, the agency wrote that "unexplained songbird mortality has wildlife biologists in NM very concerned," and asked people to collect data from birds that they find.
9-16-20 Australian stinging tree injects animals with spider-venom-like toxin
Australia may be notorious for its venomous animals, such as snakes and jellyfish, but the country is also home to dangerous plants. Some produce toxins that look very similar at the molecular level to spider and scorpion venom. Irina Vetter at the University of Queensland in Brisbane and her colleagues examined the toxins produced by two species of Australian stinging trees: the giant Australian stinging tree (Dendrocnide excelsa), which can grow to be up to 35 metres high, and the shrub-sized gympie gympie (Dendrocnide moroides), which is the most toxic of the six Dendrocnide species found in Australia. Both of these species, commonly found in rainforests in eastern Australia, are covered with felt-like hairs that can penetrate human skin and deliver the toxin – which can hospitalise people and reportedly kill horses who have brushed up against the plants. “The pain can last for such a long time,” says Vetter. “At a minimum, it lasts for 6 to 8 hours from personal experience, but it can persist and keep flaring up for days, weeks.” The team identified the trees’ primary pain-causing toxins as a group of peptides consisting of 36 amino acids. The toxins have a 3-dimensional knot-like structure that resembles the venoms found in spiders and scorpions. “They’re very dissimilar to anything we’ve seen before [in plants],” says Vetter. The researchers studied the effect of the stinging tree toxins on mice sensory neurons. They found that the toxins bind to ion channels, resulting in activation of pain receptors. “You require very little input and they will fire like crazy,” says Vetter. Stinging trees may have developed these animal-like toxins as a defence mechanism against mammals. They are likely to be insecticidal too, says Vetter, but some species aren’t affected. “Quite often, you find plants that are completely chewed apart,” she says.
9-16-20 Experts call for new era for wildlife in UK
Conservation experts are calling on the prime minister to commit to protecting nature. They say the past decade has seen far too little action, with England remaining one of the world's most nature-depleted countries. The letter to Boris Johnson was headed by Prof Sir John Lawton, who chaired a review of wildlife sites in 2010. The Making Space for Nature panel advocated "bigger, better and more joined up spaces for nature". Ten years on, there is a need for renewed action, the experts say, highlighting three overarching areas: 1. Better protection and management of wildlife habitats. 2. Scaling up efforts to restore wild areas. 3. Bringing nature to people. Prof Lawton writes: "Nearly half of our species are in decline and about a quarter of our mammals are threatened with national extinction. These losses represent a decline in resilience of the ecosystems upon which we depend and a loss of experience and joy: there are too few places left where a child can walk through a cloud of butterflies or sit amongst a rainbow of flowers." The letter is signed by members of the original panel, including Dr Peter Brotherton, director of science at the government agency, Natural England. In a second letter, a group of more than 25 nature charities urged the leaders of the four devolved nations to commit to a new era for nature in the UK. They want the UK to lead the charge for new targets and concerted global action to protect nature, following a "lost decade" of nature conservation. The UN's latest global biodiversity report shows that the world has failed to fully meet any of its targets to halt damage to natural habitats. The report from The Convention on Biological Diversity says only six of 20 goals were partially met over the last decade. The head of the CBD, Elizabeth Maruma Mrema, said that while some good things were happening, the rate of biodiversity loss was unprecedented in human history and it showed the pressures were intensifying. The announcement follows a report by WWF and the Zoological Society of London that shows animal populations globally have plunged by 68% in the last 50 years.
9-16-20 The horn-like knobs on a giraffe's head can be a deadly lightning rod
During a freak rainstorm on 29 February, two giraffes were struck by lightning in Rockwood, a conservation area in South Africa. While it may seem unsurprising that the tallest animals on the planet face this hazard, scientists had never described this occurrence in any detail until now. “It came as a bit of a surprise to me because the whole day was quite quiet in weather, and suddenly there was this big storm,” says Ciska Scheijen, a conservation scientist at Rockwood who had been following a group of eight giraffes in the area for about a year. The storm only lasted a few hours, but Scheijen says she immediately suspected something was wrong with the herd afterwards, as she could only see six of the animals. “It’s very rare for that group to separate.” Rockwood ranger Frans Moleko Kaweng went out to investigate and it quickly became apparent what had happened. The oldest and tallest giraffe of the herd, the matriarch, was lying dead with a wound on top of her head. It appeared as if one of her ossicones – the horn-like knobs on a giraffe’s head – may have acted as a lightning rod in the storm. “It looked like the ossicone broke off,” says Scheijen. The body of a younger female lay 7 metres away. She was probably killed by a side flash from the strike or by ground current, as she was standing close to the other giraffe. Scheijen also noted a strong smell of ammonia, a phenomenon described in other lightning strikes on animals. She suggests it was this strong odour that kept almost all scavengers away from the carcasses for a day and a half, a strange occurrence for this area. There were bite marks seen on one giraffe from just one jackal. No trees were nearby when the storm broke, says Scheijen, but scientists are still uncertain whether the lanky ungulates typically hide under taller trees to avoid lightning strikes during storms.
29-15-20 Hong Kong's dolphins make pandemic comeback
Restrictions during the coronavirus pandemic mean there are hardly any boats and ferries around Hong Kong. The vulnerable Chinese white dolphin is making a comeback as a result, with sightings up about 30%.
9-15-20 Gene editing to produce 'super dad' livestock
Scientists have produced gene-edited animals they say could serve as "super dads" or "surrogate sires". The pigs, goats, cattle and mice make sperm carrying the genetic material of donor animals. The researchers used a hi-tech gene editing tool to knock out a male fertility gene in animal embryos. The animals were born sterile, but began producing sperm after an injection of sperm-producing cells from donor animals. The technique would enable surrogate males to sire offspring carrying the genetic material of valuable elite animals such as prize bulls, said a US-UK team. This would be a step towards genetically enhancing livestock to improve food production, they added. Prof Jon Oatley, of Washington State University's College of Veterinary Medicine, said: "This can have a major impact on addressing food insecurity around the world. If we can tackle this genetically, then that means less water, less feed and fewer antibiotics we have to put into the animals." The surrogate sires were confirmed to have active donor sperm. And the mice fathered healthy offspring that carried the genes of the sperm donor. The larger animals have not yet been bred. But Prof Bruce Whitelaw of the Roslin Institute at the University of Edinburgh said the study provided a powerful proof of concept. "This shows the world that this technology is real. It can be used," he said. "We now have to go in and work out how best to use it productively to help feed our growing population." According to the researchers, the technology could also help in the conservation of endangered species. It might be possible, for example, to use the frozen sperm of an endangered rhino to regenerate the species. But they said the speed at which the science could be put into action will be influenced by policymakers. Gene-edited livestock have yet to be granted approval for human consumption, with concerns over product safety, ethics, and animal welfare.
9-14-20 Cloned testicles let goats father the offspring of another male
Even the hottest stud can only sire so many offspring. To speed up livestock breeding, biologists have created pigs, goats and mice whose testicles are effectively clones of those of a different male, meaning these animals father that male’s offspring. “It will allow more farmers to get hold of animals with the characteristics they want,” says Bruce Whitelaw at the Roslin Institute in the UK. “Many people did not think this would work.” The first step in the process is to create host animals that cannot produce their own sperm. This is done by using the CRISPR gene-editing method to disable a gene called NANOS2. Next, sperm-producing stem cells are taken from the testicles of another male and injected into those of the young hosts. When the hosts become sexually mature, they start producing the sperm of the donor male. The team has done this in pigs, goats and mice, and is working on doing it in bulls. Three host mice have produced 111 offspring by normal mating so far. The offspring don’t inherit any DNA from the host, so their nature depends only on that of their genetic parents, says team member Jon Oatley at Washington State University. These parents could be conventionally bred animals or they could be genetically modified in some way. “These surrogates could then be hosts for producing sperm carrying the genetics of a desirable or superior male,” he says. Such traits might include disease resistance, heat tolerance or improved production of meat or milk, says team member Irina Polejaeva at Utah State University. Artificial insemination is already used to pass on desirable traits. But skilled personnel and special equipment are needed for every single insemination, and it is only widely used in dairy farming, says Whitelaw.
9-12-20 Sir David Attenborough makes stark warning about species extinction
Sir David Attenborough returns to our screens this weekend with a landmark new production. The tone of the programme is very different from his usual work. For once Britain's favourite naturalist is not here to celebrate the incredible diversity of life on Earth but to issue us all with a stark warning. The one-hour film, Extinction: The Facts, will be broadcast on BBC One in the UK on Sunday 13 September at 20:00 BST. "We are facing a crisis", he warns at the start, "and one that has consequences for us all." What follows is a shocking reckoning of the damage our species has wrought on the natural world. There are the stunning images of animals and plants you would expect from an Attenborough production, but also horrific scenes of destruction. In one sequence monkeys leap from trees into a river to escape a huge fire. In another a koala limps across a road in its vain search for shelter as flames consume the forest around it. There is a small army of experts on hand to quantify the scale of the damage to the ecosystems of the world. Of the estimated eight million species on Earth, a million are now threatened with extinction, one expert warns. Since 1970, vertebrate animals - birds, mammals, reptiles, fish and amphibians - have declined by 60%, another tells us. We meet the world's last two northern white rhinos. These great beasts used to be found in their thousands in Central Africa but have been pushed to the brink of extinction by habitat loss and hunting. "Many people think of extinction being this imaginary tale told by conservationists," says James Mwenda, the keeper who looks after them, "but I have lived it, I know what it is." James strokes and pets the giant animals but it becomes clear they represent the last of their kind when he tells us that Najin and Fatu are mother and daughter. Species have always come and gone, that's how evolution works. But, says Sir David, the rate of extinction has been rising dramatically. It is reckoned to be now happening at 100 times the natural evolutionary rate - and is accelerating.
9-12-20 Attenborough and the special moment fuelling his hope
In 2019, over 500 scientists found that biodiversity was being lost at rates not seen before in human history. But the evidence suggests that, if the right choices are made at this critical moment, nature can bounce back. When David Attenborough visited the mountain gorillas of Rwanda 40 years ago, they were on the brink of extinction. Now, decades of effort later, they number over 1,000 and include the descendants of those David met.
9-11-20 Mountain lions in Los Angeles are so inbred they have L-shaped tails
The mountain lions in Los Angeles’s Santa Monica mountains are so isolated from other cats – hemmed in by freeways and urban development – that biologists have long been worried they are at high risk of becoming inbred to the point of sterility. This week, researchers in California documented signs that inbreeding is already severe enough to manifest in the lion’s appearance: three have L-shaped kinks at the end of their tails. What’s more, some of the males have cryptorchidism, a condition in which the testes fail to descend. The local genetic diversity of mountain lions is the lowest of any lion population in the western US. A population in Florida in the eastern US – where the species is known as the Florida panther – had lower genetic diversity a few decades ago. Those cats also developed abnormalities. “We’re seeing some of those exact same defects as Florida panthers,” says Seth Riley, the National Park Service (NPS) wildlife branch chief of the Santa Monica Mountains National Recreation Area, who led the study. Matings between offspring are common and some LA lions kill others to secure access to territory and mates. Just a handful have successfully navigated across the region’s highways over the last two decades, and many have died trying. Holly Ernest at the University of Wyoming says that just one migrant cat can enhance a struggling population and that the abnormalities are “definitely concerning”. “This is something we hoped to never see,” said Jeff Sikich, the NPS wildlife biologist who discovered the first kink-tailed mountain lion in March. It is unclear whether tail variations effect sexual selection – for instance, if females will reject males with the kinked tails – but the species has displayed other odd features. In 2016, a young male in Idaho was found with a tooth growing out of his head, although this looks more like a chromosomal aberration than the result of inbreeding, says Kyle Gustafson at Arkansas State University.
9-11-20 This moth may outsmart smog by learning to like pollution-altered aromas
Scientists taught tobacco hawkmoths that an ozone-affected scent is from a favorite flower. Pollution can play havoc with pollinators’ favorite flower smells. But one kind of moth can learn how to take to an unfamiliar new scent like, well, a moth to a flame. Floral aromas help pollinators locate their favorite plants. Scientists have established that air pollutants scramble those fragrances, throwing off the tracking abilities of such beneficial insects as honeybees (SN: 4/24/08). But new lab experiments demonstrate that one pollinator, the tobacco hawkmoth (Manduca sexta), can quickly learn that a pollution-altered scent comes from the jasmine tobacco flower (Nicotiana alata) that the insect likes. That ability may imply that the moth can find food and pollinate plants, including crucial crops, despite some air pollution, researchers report September 2 in the Journal of Chemical Ecology. Scientists already knew that some pollinators can learn new smells, but this is the first study to demonstrate an insect overcoming pollution’s effects on odors. Chemical ecologist Markus Knaden and colleagues focused on one pollutant — ozone, the main ingredient in smog. Ozone reacts with flower aroma molecules, changing their chemical structure and therefore their fragrance. In Knaden’s lab at the Max Planck Institute for Chemical Ecology in Jena, Germany, his team blew an ozone-altered N. alata scent from a tiny tube into a refrigerator-sized plexiglass tunnel, with a moth awaiting at the far end of the tunnel. Usually, when the moth smells the unaltered floral fragrance, it flies upwind and uses its long, skinny mouthparts to probe the tube the way that it would a blossom. The researchers expected that the modified scent might throw the moth off a little. But the insect wasn’t attracted at all to a flower aroma exposed to levels of ozone that are typical on some hot, sunny days.
9-10-20 TAustralian labradoodle is more poodle than Labrador, according to DNA
Genetic analysis of the Australian labradoodle reveals that most of its genes come from the poodle, highlighting how small differences in genomes can result in new distinct breeds. In the 1980s, a concerted effort began to produce a guide dog with a reduced likelihood of triggering allergic reactions in humans. The result is the Australian labradoodle – a cross between a Labrador retriever and a standard poodle, which doesn’t shed much hair that can trigger an allergic response. “Australian labradoodles are one of the most popular designer-breeds in the United States,” says Elaine Ostrander at the US National Institutes of Health. “I see three of them on my street alone. Labradors are smart and trainable, but there is a big desire to have dogs that elicit a low allergy response.” For 30 years, the Australian labradoodle has been selectively bred to establish a population that could be recognised as a true breed rather than a mix. Now, Ostrander and her colleagues have explored how this 30-year-long programme of selective breeding has influenced the Australian labradoodle’s genetics. They analysed the DNA of 21 Australian labradoodles, and compared this with DNA from purebred Labradors and poodles. The researchers also examined DNA from so-called first-generation labradoodles – which are simply the offspring of any cross between a Labrador and a poodle. The team looked at over 150,000 random points in the dogs’ genomes and compared them with each other. Unsurprisingly, first-generation labradoodles were a 50:50 mix between Labrador and poodle DNA. But after 30 years of breeding, the Australian labradoodle’s genome is composed nearly entirely of poodle DNA. They also found that Australian labradoodles had a higher than expected frequency of gene variants related to the dog’s coat. These findings suggest that the genes for a poodle’s coat, which breeders presumably wanted to dominate, have dragged large portions of the rest of the poodle’s chromosomes into the labradoodle along with it.
9-10-20 Wildlife populations are seeing 'catastrophic' rapid declines
Global wildlife populations are declining rapidly, according to the 2020 Living Planet Report by the conservation group WWF. It reveals that global populations of mammals, birds, amphibians, reptiles and fish have fallen an average of 68 per cent globally since 1970, declining at a rate faster than previously predicted. “Let’s be clear: this is catastrophic,” says Mark Wright at WWF in the UK. “Despite ongoing verbal and written commitments by governments around the world and by businesses around the world to seriously address the climate crisis… we are clearly failing,” he says. The report draws on data from the Living Planet Index, produced by the Zoological Society of London. The index tracked global biodiversity between 1970 and 2016, based on the monitoring of 20,811 populations of 4392 vertebrate species. The largest drops identified in the report are in South America, Central America and the Caribbean, where the average size of monitored wildlife populations has declined by 94 per cent. It also highlights that three-quarters of ice-free land on Earth has been significantly changed by human activity and more than 85 per cent of the area of wetlands has been lost globally. Nearly one-in-three freshwater species around the world are now threatened with extinction, and the 3741 freshwater populations monitored showed an average decline of 84 per cent since 1970. In the UK, grey partridge populations declined by 85 per cent between 1970 and 2004, probably due to agricultural intensification. But some animal populations have increased through conservation efforts: in the six years to 2014, the tiger population of Nepal rose by 64 per cent, while loggerhead turtles increased by 154 per cent in a protected area off the coast of South Africa between 1973 and 2009.
9-10-20 Wildlife in 'catastrophic decline' due to human destruction, scientists warn
Wildlife populations have fallen by more than two-thirds in less than 50 years, according to a major report by the conservation group WWF. The report says this "catastrophic decline" shows no sign of slowing. And it warns that nature is being destroyed by humans at a rate never seen before. Wildlife is "in freefall" as we burn forests, over-fish our seas and destroy wild areas, says Tanya Steele, chief executive at WWF. "We are wrecking our world - the one place we call home - risking our health, security and survival here on Earth. Now nature is sending us a desperate SOS and time is running out." The report looked at thousands of different wildlife species monitored by conservation scientists in habitats across the world. They recorded an average 68% fall in more than 20,000 populations of mammals, birds, amphibians, reptiles and fish since 1970. The decline was clear evidence of the damage human activity is doing to the natural world, said Dr Andrew Terry, director of conservation at the Zoological Society of London (ZSL), which provides the data. "If nothing changes, populations will undoubtedly continue to fall, driving wildlife to extinction and threatening the integrity of the ecosystems on which we depend," he added. The report says the Covid-19 pandemic is a stark reminder of how nature and humans are intertwined. Factors believed to lead to the emergence of pandemics - including habitat loss and the use and trade of wildlife - are also some of the drivers behind the decline in wildlife. New modelling evidence suggests we can halt and even reverse habitat loss and deforestation if we take urgent conservation action and change the way we produce and consume food. The British TV presenter and naturalist Sir David Attenborough said the Anthropocene, the geological age during which human activity has come to the fore, could be the moment we achieve a balance with the natural world and become stewards of our planet.
9-9-20 Hummingbirds can drop their body temperature below 4°C when they rest
Hummingbirds can enter a hibernation-like state at night, dropping their body temperature to under 4°C in an effort to preserve energy for use during the day. The birds are among the few animals, including night hawks and some small rodents, that are capable of torpor, in which body function reduces to a bare minimum for a few hours, says Blair Wolf at the University of New Mexico. Previous studies have found that hummingbirds can drop their body temperature from 40°C to about 17°C at night, but now Wolf and his colleagues have found that some species can go much further, reaching 3.26°C. “You’d think they’re frozen,” he says. “They feel like a cold rock.” By day, the birds expend massive amounts of energy, hovering while consuming nectar from 400 to 600 flowers. At night, they can reduce energy expenditure by upwards of 95 percent. Even their heart rate drops, falling from 1000 beats per minute down to around 50, says Wolf. He and his team studied six species of hummingbirds thriving at up to 4000 metres above sea level in the Peruvian Andes. They trapped individuals overnight and inserted tiny probes into the cloaca (hind orifice) to monitor body temperatures from evening to morning, including the 12 night-time hours when outdoor temperatures dropped to between 2 and 6°C. Most of the birds, representing all six species, entered torpor in bouts lasting from two to almost 13 hours, says Wolf. Body temperatures varied, but it was the black metaltail species that came closest to outdoor temperatures, hitting a low of 3.26°C. At around sunrise, the birds started quivering, increasing body temperature by more than 1°C per minute. Although reheating requires a lot of energy, the amount saved by staying in torpor exceeded this cost. The team weighed the birds and found that those spending less time in torpor lost more weight, indicating they had used more energy in the night.
9-9-20 This hummingbird survives cold nights by nearly freezing itself solid
The black metaltail goes into a state of suspended animation, becoming ‘cold as a rock’. The high Andes mountains of Peru are a hummingbird’s paradise, rich in wildflower nectar and low in predators. But there’s one problem: the cold. Nighttime temperatures often dip below freezing in these rainy tropical highlands. How does a six-gram bird that needs nectar from 500 flowers a day just to survive get enough extra energy to keep itself warm all night? It doesn’t. Instead, as temperatures drop with the sun, these hummingbirds enter a state of suspended animation known as torpor. One species, the black metaltail (Metallura phoebe), chills to 3.26° Celsius, the coldest body temperature ever recorded in a bird or non-hibernating mammal, researchers report September 9 in Biology Letters. “They’re cold as a rock,” says Blair Wolf, a physiological ecologist at the University of New Mexico in Albuquerque. “If you didn’t know better you’d think they were dead.” Cooling to near-death temperatures lets the hummingbirds save precious energy, allowing them to survive the cold night and gear up to feed the next day, Wolf says. Torpor had been observed before in hummingbirds, but Wolf and his colleagues wanted a more detailed picture. They placed 26 individuals of six different species in cages overnight and inserted the equivalent of miniature rectal thermometers into their cloacas. Perched and upright, the birds pointed their bills upwards, fluffed their feathers and stopped moving. All of the species entered some kind of torpor, but the black metaltail cooled the most, dropping from a daytime temperature of about 40° C to just above freezing. During the day, these hummingbirds’ tiny-yet-mighty hearts can beat 1,200 times a minute to power their frenetic lifestyle. But during torpor, their heart rates plummet to as low as 40 beats a minute. “It’s an astounding drop,” Wolf says, and it could allow these high-altitude birds to cut their energy use by about 95 percent. By not wasting energy trying to stay warm, these birds can thrive as high as 5,000 meters above sea level. “It’s a remarkable adaptation.”
9-8-20 My Octopus Teacher review: The strange lives of cephalopods up close
In many ways, the octopus is a tough proposition: a soft-bodied mollusc that carries the bulk of its brain in its arms, that can render itself solid without a skeleton or liquid despite its beak, that evolved separately from nearly every other organism on Earth. That otherness is at the heart of our fascination with octopuses: can we even aspire to understand something so foreign? A new Netflix documentary, My Octopus Teacher, follows one man’s attempt. Wanting to reconnect with nature after burning out with work, film-maker and naturalist Craig Foster starts freediving daily in the undersea kelp forests off Cape Town. One day, he comes across an odd jumble of shells on the sea floor. It transpires to be a common octopus, hiding in plain sight. Viewers of the BBC’s Blue Planet 2 may recognise the footage. The octopus and its protective “shell suit” featured in the “Green Seas” episode, explained by David Attenborough as never-before-seen behaviour. Foster collaborated on shooting the sequence with his friend, Blue Planet 2 cameraman Roger Horrocks. The pair have spent many years documenting South Africa’s kelp forests (more recently, as part of the non-profit Sea Change Project) and are listed as joint directors of photography on My Octopus Teacher. But that back story is omitted in favour of a close crop on Foster’s personal relationship with the octopus, and what he learns on his daily visits to her world. Although three expert advisers are credited on the film (including “octopus psychologist” Jennifer Mather, who flew from Canada to consult on the edit), Foster’s takeaways tend to be emotive, rather than scientific. Indeed, his eagerness to find similarities can rather sell his subject short. When Foster suggests their “lives were mirroring each other” as the octopus regrows a leg bitten off by a shark, you wonder if she would agree.
9-8-20 Sea butterflies’ shells determine how the snails swim
Aquarium videos show species rise and sink at different angles and speeds. Sea butterflies flit through the ocean on gossamer wings, each species with a style of its own. These tiny marine snails, or thecosomes, migrate up to surface waters at night to feed and sink to deeper waters during the day to hide from predators. But exactly how they move through the water has remained a mystery, as these delicate creatures survive only a couple days in captivity. New videos of sea butterflies in an aquarium reveal that snail species swim and sink at different angles and speeds, depending on the sizes and shapes of their shells, researchers report online September 7 in Frontiers in Marine Science. The finding could help biologists better understand marine snail migration, and inspire new designs for underwater robots (SN: 1/3/18). Mechanical engineer David Murphy of the University of South Florida in Tampa and colleagues videotaped seven species of sea butterflies collected off Bermuda. The catch included two tiny species with coiled shells about 1 millimeter across, four midsize species with long, conical or urn-shaped shells of about 7 to 11 millimeters, and one species with a flat shell up to 14 millimeters across. “It’s pretty remarkable how graceful the motion of their wings is,” Murphy says. “Just really beautiful to watch.” All the sea butterfly species propelled themselves along zigzagging paths as they flapped their wings. Those wingbeats also caused bodies of the tiny, coiled shell species and the midsize, long shell snails to rock back and forth as they swam. Snails with coiled or elongated shells tended to swim straight up, and to sink straight down whenever they stopped flapping, their shells hanging like pendulums beneath their wings. But the species with a wide, flat shell, Diacria trispinosa, climbed at a shallower angle and drifted sideways as it sank, potentially due to lift generated by its shell.
9-9-20 The amusing skulduggery-filled tale of how beavers returned to Britain
From photocopying secret files to taking on the powerful lobby groups, activist Derek Gow's book Bringing Back the Beaver tells his side of the story of Britain's beaver reintroduction. LAST month, the UK government made a long-anticipated ruling on the future of a colony of beavers that has been living freely on the River Otter in Devon since at least 2014. Against expectations, it decided they could stay – the first time an extinct native mammal has been legally reintroduced into the wild in England. Scotland’s government made a similar call in 2016, and in 2019 declared the beaver to be a protected species. As Derek Gow says in his charmingly irascible little book Bringing Back the Beaver: “In England, Wales and Scotland, beavers are returning. Slowly.” Gow, a farmer-turned-zookeeper-turned-ecologist, has done as much as anyone to make it happen, though he makes it clear that it would have happened much more quickly were it not for the implacable hostility of a handful of powerful interest groups. Gow cut his conservation teeth reintroducing endangered water voles, and he helped to establish the UK’s first enclosed beaver trial at Ham Fen nature reserve, near Sandwich in Kent. He has been fighting tirelessly to reintroduce beavers ever since, often against entrenched opposition. His “war” stories make up most of the book and they are a great, though maddening, read. At every turn, he and his fellow conservationists are stymied by pettifogging bureaucrats, ignorant politicians, grumpy farmers, greedy landowners and the hunting, shooting and fishing lobby. All of these Gow regards as fools – whom he doesn’t suffer gladly. His portrayal of them is brutal, and the times when he outwits them are recounted with relish.
9-7-20 The woman trying to save India's tortured temple elephants
Sangita Iyer is on a mission. As a child, the documentary maker, who was born in the Indian state of Kerala but now lives in Toronto, saw ceremonial elephants being paraded and thought they were beautiful. Later, she learned about the ordeal the animals are subjected to. "So many elephants had ghastly wounds on their hips, massive tumours and blood oozing out of their ankles, because chains had cut into their flesh and many of them were blind," Iyer told the BBC. She has made a documentary, Gods in Shackles, in an attempt to draw attention to the treatment of temple elephants she saw in India. "They were so helpless and the chains were so heavy," she said. "It was absolutely heart-breaking for me to witness this." Hindu and Buddhist traditions give elephants an elevated status. For centuries, temples and monasteries have used them to perform sacred duties. Devotees even seek blessings from them. The reputation of some elephants outlives their time on Earth. Near Kerala's well-known Guruvayur Temple you will find a life-size concrete statue of a much loved elephant called Kesavan. Its tusks adorn the entrance of the temple. It is claimed that Kesavan circled the temple before collapsing and dying in 1976, aged 72. It is common to see people gather to mourn the death of temple elephants - even if they are not that famous. "They torture the elephants to death, and after their death they light lamps and shed crocodile tears, as though they really feel sad for these elephants," Iyer said. Ceremonial elephants are used in temples across India, but their presence is extensive in Kerala. The state is home to about a fifth of the country's roughly 2,500 captive elephants. The animals are owned by temples as well as individuals. Guruvayur temple alone has more than 50 elephants.
9-7-20 Woodpecker battle royale sees teams of birds fight for nearly a week
When acorn woodpeckers spot a potential new home, they join forces with their brothers and sisters for a battle royale. Up to a dozen teams of two or three woodpeckers fight to claim the spot for up to 10 hours per day for almost a week, with spectator birds flying in from kilometres away. Sahas Barve at the Smithsonian National Museum of Natural History in Washington DC and his colleagues studied the movements of acorn woodpeckers in the Hastings Natural History Reservation in California. They tracked the movements of birds using solar-powered radio tags during three separate battle events in 2018 and 2019. The battles, which lasted five consecutive days, were triggered by vacancies in oak trees containing acorn granaries – large storage structures that generations of birds have built, which consist of acorns stuffed into thousands of individual holes. The sibling teams hope to join the successful birds already living there. “It’s like the most affluent family in the neighbourhood – when there’s a chance to become a breeder in those families, that when those big power struggles happen,” says Barve. The conflicts are triggered by new vacancies in both male and female birds, but the researchers only studied battles between teams of female acorn woodpeckers. “At any given power struggle there can be upwards of 30 to 40 birds fighting,” says Barve. The birds fight in sibling coalitions, with the winners needing to defeat all other rival teams. Some birds are seriously injured or killed. “This sort of effort has not been documented in birds before,” says Barve. The conflicts drew spectators who lived farther away than the battling birds, some from more than 3 kilometres away. These spectator woodpeckers flew in daily and spent almost an hour watching the fight, despite many having their own acorn granaries.
9-6-20 Mystery seeds: Amazon bans foreign plant sales in US
Amazon says it has banned foreign sales of seeds in the US after thousands of Americans received unsolicited packets of seeds in the mail, most from China. The online retail giant told the BBC that it will now only allow the sale of seeds by sellers based in the US. US officials said gardeners should not plant seeds of unknown origin. The packages are believed to be part of a global "brushing" scam to gain positive reviews for online selling sites. Amazon's new guidelines, in effect since 3 September, also prohibit the sale of seeds within America by non-US residents. It added that sellers may be banned if they do not follow the new guidelines. But the retailer has not confirmed if its ban will extend to other countries. News of the policy change was first reported by the Wall Street Journal. At least 14 plant species have been identified among the mystery packages, including mint, lavender and roses. Unsolicited seed packages are also being reported in other countries, including the UK. Last month Scottish authorities advised people not to handle the seeds, for fear they could damage local ecosystems. In an update on 11 August, the US Department of Agriculture (USDA) said experts analysing the seeds found few problems with them, and that China was assisting with investigations. But the USDA has warned people against planting the seeds, saying they could be non-native species or carry pests and diseases. So-called "brushing" scams involve sellers sending out low value items such as seeds or rings. Each fake "sale" then generates an online review that appears to boost the seller's legitimacy.
9-5-20 Earth's 'lost species' only the tip of the iceberg
Scientists have calculated how many mammals might be lost this century, based on fossil evidence of past extinctions. Their predictions suggest at least 550 species will follow in the footsteps of the mammoth and sabre-toothed cat. With every "lost species" we lose part of the Earth's natural history, they say. Yet, despite these "grim" projections, we can save hundreds of species by stepping up conservation efforts. The new research, published in the journal Science Advances, suggests that humans are almost entirely responsible for extinctions of mammals in past decades. And rates will escalate in the future if we don't take action now. Despite this "alarming" scenario, we could save hundreds if not thousands of species with more targeted and efficient conservation strategies, said Tobias Andermann of the Gothenburg Global Biodiversity Centre and the University of Gothenburg. In order to achieve this, we must increase our collective awareness about the "looming escalation of the biodiversity crisis, and take action in combatting this global emergency". "Time is pressing," he said. "With every lost species, we irreversibly lose a unique portion of Earth's natural history." The scientists compiled a large dataset of fossils, which provided evidence for the timing and scale of recent extinctions. Their computer-based simulations predict large increases in extinction rates by the year 2100, based on the current threat status of species. According to these models, the extinctions that have occurred in past centuries only represent the tip of the iceberg, compared with the looming extinctions of the next decades. "Reconstructing our past impacts on biodiversity is essential to understand why some species and ecosystems have been particularly vulnerable to human activities - which can hopefully allow us to develop more effective conservation actions to combat extinction," said Prof Samuel Turvey of ZSL (Zoological Society of London).
9-5-20 Protecting half the planet could help solve climate change and save species
A new map shows where new land protections could complement existing conserved areas. Earth faces two interrelated crises: accelerating loss of biodiversity and climate change. Both are worsened by human development of natural lands that would otherwise allow species to flourish and would store atmosphere-warming carbon, stabilizing the climate. A new study argues that nations can help avert the biodiversity and climate crises by preserving the roughly 50 percent of land that remains relatively undeveloped. The researchers dub that conserved area a “Global Safety Net,” mapping out regions that can meet critical conservation and climate goals in a study published September 4 in Science Advances. Eric Dinerstein, a conservation biologist at RESOLVE, a nonprofit based in Washington, D.C., and colleagues began by mapping out existing protected areas, which cover about 15 percent of land. The team then sequentially added slices of land needed to meet different conservation goals, using existing biodiversity databases. To protect species most threatened by extinction that aren’t already protected, an extra 2.3 percent of land would need to be set aside. The researchers also identified new areas that could preserve hot spots of exceptional species diversity, and large tracts of wilderness needed to support wide-ranging animals like caribou. Much of the land identified as important for biodiversity also stores a lot of carbon, underlining the connection between conservation and climate goals. But the researchers found an additional 4.7 percent of land, including forests in the northeastern United States, that would help keep climate-warming carbon out of the atmosphere. Providing some level of protection or sustainable management for these lands could achieve various climate and conservation goals, the researchers argue. But Dinerstein says nations must act much faster than they are to protect these areas. Currently, governments are drafting plans to protect 30 percent of the globe by 2030 (SN: 4/22/20). “That’s not fast enough,” he says. “We have to achieve a whole lot more in a decade than what people are arguing for.”
9-4-20 This parasitic plant eavesdrops on its host to know when to flower
Dodders look like tapeworms, and act a bit like one too. A dodder plant begins its life looking like a tapeworm. The tiny plant, which will never grow leaves or roots, elongates in a spindly spiral. Round and round it swirls, searching for a host plant. When the dodder finds one, it latches on and infiltrates the host with tiny tubes that siphon off water and nutrients. The parasitic dodder grows, eventually covering its victim in a tangled, threadlike web of orange or yellow stems. Then, when the host plant flowers, so does the dodder, setting the stage for the sinister cycle to begin again. But that last part, reproduction, has remained a mystery. Normally, flowering plants use their leaves to sense when the environmental conditions are right to flower. So how does a parasitic plant with no leaves sense when to flower? By eavesdropping, a new study shows, using a chemical signal from the dodder’s host as its own. Australian dodder plants (Cuscuta australis) absorb the chemical that triggers flowering, a protein called Flowering Locus T, or FT, from their hosts and use it to flower synchronously, researchers report August 31 in the Proceedings of the National Academy of Sciences. This synchronization maximizes the dodder’s growth and reproduction, and may be part of why the plant parasite, which consists of over 100 different species, has spread around the world, parasitizing organisms as different as alfalfa and acacia trees (SN: 8/23/08). “Synchronizing flowering really makes sense for these plant parasites,” says Jianqiang Wu, a botanist at the Chinese Academy of Sciences’ Kunming Institute of Botany. If a dodder flowers too soon, it won’t grow as large as it could have and will produce fewer seeds. Too late and its host may have already died, leaving the dodder with less nutrients to support flowering.
9-3-20 Shark researchers size up real 'Megalodon' for first time
The enormity of a prehistoric mega-shark made famous in Hollywood films has finally been revealed by researchers. Until now, only the length of the Otodus Megalodon, as featured in the 2018 film The Meg, had been estimated from fossils of its teeth. However a team from Swansea and Bristol universities have combined maths with nature to reveal just how big it was. The study has been published in the journal Scientific Reports. Researchers used mathematical methods and comparisons with living relatives to find the overall size of the megalodon, which lived from about 23 million to three million years ago. Results suggest a 16m (52ft) megalodon - almost three times as long as a great white shark - is likely to have had a head about 4.65m (15ft) long, a dorsal fin as large as an entire adult human and a tail about 3.85m (13ft) high. Jack Cooper, who is to study a PHD in palaeobiology at Swansea University, described the research as his "dream project". "Megalodon was the very animal that inspired me to pursue palaeontology but studying the whole animal is difficult considering all we really have are lots of isolated teeth," he said. "It's significant that we have now been able to produce estimates of proportions and dimensions of the body parts when there are no fossils to go off. "However the dimensions in the film were actually pretty accurate." Previously, the shark was only compared with the great white, but the latest analysis was expanded to include five modern sharks, including the makos, salmon shark and porbeagle shark. Mr Cooper added: "We could take the growth curves of the five modern forms and project the overall shape as they get larger and larger - right up to a body length of 16 metres."
9-3-20 Trees and shrubs might reveal the location of decomposing bodies
Plants may be able to help investigators find dead bodies. Botanists believe the sudden flush of nutrients into the soil from decomposition may affect nearby foliage. If scientists can understand those changes – for instance, the effect they have on leaf colour – they may be able to identify where remains are buried simply by studying foliage features in aerial images. “If we’re able to use the plants as sensors, at least first as indicators or crude indicators, we can identify whether a missing body may be close by,” says Neal Stewart Jr, a botanist at the University of Tennessee. Search teams looking for human remains often rely on aerial searches, but these are difficult if a cadaver is buried in a forest. Although pedestrian surveys or teams of trained dogs can help in these situations, in very large forests or in war zones, it becomes impractical to search for human remains this way. The hope is that features of the foliage can reveal the presence of a body, offering a new way to locate missing bodies – particularly given that anecdotal evidence suggests visual signals can appear in the leaves of trees and shrubs growing near a body. Forensic anthropologists at the University of Tennessee have been training members of the FBI for 20 years. This includes rudimentary “forensic botany”. For instance, a body can affect the mix of plant species growing nearby and plant leaves may be visibly darker, indicative of higher nitrogen uptake. Now, the plan is to explore those botanical effects more thoroughly and systematically at a “body farm” at the university, where researchers study the way cadavers decompose with time. The farm was the first of its kind when it was created in the 1980s. “We’ve actually built a whole plant imager that can analyse fluorescence signatures,” says Stewart. “But the first steps are going to be very fine scale, looking at individual leaves and measuring how their reflectance or fluorescence changes over time when plants are near human remains.”
9-3-20 Secrets of male elephant society revealed in the wild
Older male elephants have an important role to play in the survival of the species by passing on their skills and knowledge to younger males, a study of African elephants suggests. Matriarchs lead groups of daughters and their calves, while males grow up and leave the herd. Mature bull elephants play an important role in leading these younger males, researchers have found. And their loss by poaching or hunting could have "disastrous impacts". The study, published in the journal Scientific Reports suggests older bulls are likely to occupy a similar role in male society as matriarchs in female breeding herds. "It has long been known that older females make more effective leaders of breeding herds due to their enhanced experience - we provide compelling support for a similar role of older males in the male society," said Connie Allen of the University of Exeter and charity Elephants for Africa. The researchers investigated the behaviour of more than 1,250 male African savannah elephants travelling to and from the Boteti River in the Makgadikgadi Pans National Park, Botswana. Lone male elephants accounted for a fifth of sightings on elephant pathways using camera traps, with adolescent males travelling along these routes less often than expected, suggesting lone travel is riskier for younger and less experienced males. Mature adult bulls were more likely to travel at the front of groups of males, suggesting they may be important leaders with valuable ecological knowledge. The idea that lone older males do little for the survival of the species has been used as an argument to support the legal trophy hunting of old males. However, the new research suggests that killing older males could have "disastrous consequences" in removing key figures in male elephant society. The oldest bulls, with potentially decades more experience of utilising the environment and navigating crucial resources, in our study were more likely to lead all-male groups," said Connie Allen.
9-3-20 Naked mole rats are nearly deaf because their ears can’t amplify sound
Naked mole rats have poor hearing because, unlike other mammals, they have abnormal outer hair cells that can’t amplify sound. The animals could be used to model human deafness and help develop treatments. “Naked mole rats are fascinating creatures,” says Sonja Pyott at the University of Groningen in the Netherlands. Not only do they live exclusively underground, they are blind, have poor hearing and make loud, piercing cries. Pyott and her colleagues focused their research on naked mole rats (Heterocephalus glaber) and Damaraland mole rats (Fukomys damarensis), aiming to determine what causes this poor hearing and how this trait may have evolved. The team first measured the animals’ neural responses to various tones played to them. This confirmed that they struggled to hear quiet sounds and could only perceive sound between a narrow frequency, between 0.5 and 4 kiloHertz. Humans, by contrast, can detects sounds between about 0.02 and 20 kHz. The researchers then recorded the sound transmitted by the cochlea, a part of the inner ear typically shows the ear is amplifying sound information. They found that no such amplification occurred in either species of mole rat. The team used a scanning electron microscope to look more closely at the outer hair cells of the mole rats’ ears. The hair cell bundles in a particular section of the ear were found to be abnormal compared with those of other rodents, like mice and gerbils. Using a genotype library, the researchers were able to link the proteins involved in abnormal hair cell bundles to human deafness. “Using this database, we could identify small changes in proteins essential for hearing in both mole rats and humans that give rise to hearing loss and deafness” says Pyott.
9-3-20 Scientists have the answer to a tadpole mystery
Scientists have discovered how to identify frogs from their tadpoles in a step towards saving amphibians from extinction. Conservation efforts to protect the breeding grounds of endangered frogs has been hampered by the difficulty of telling tadpoles apart. Now researchers have solved the puzzle for frogs living in Vietnam's remote forests. Their work on Asian horned frogs will help stop amphibians being lost. Some survive only in small areas of forests which are fast being altered or destroyed. Benjamin Tapley, curator of reptiles and amphibians at international conservation charity ZSL (Zoological Society of London), said: "These frogs occur in some of the most exploited forests on Earth and are suffering from rapid habitat loss and degradation." Tadpoles are a common sight in streams for several months of the year, but once they become frogs they disappear into undergrowth or up trees, where they may never be seen again. As frogs and their tadpoles look nothing like each other, It's important to know which tadpole becomes which frog, he explained. "It helps us detect the presence of a species, especially as adult frogs can be seasonally active and difficult to find, and allows us to identify which places might be important frog breeding sites that need protection," said Dr Tapley. The researchers collected geographical data, took photographs and made measurements of tadpoles, comparing their DNA to samples from adults of known frog species. They were able to identify the tadpoles of six species of Asian horned frogs found in Vietnam's mountain forests. The tadpoles are unusual, with funnel-like mouthparts, while the adults, named for the horn-like projections above their eyes, are brown with skin folds that resemble leaf veins helping in camouflage on the forest floor. There are more than 250 species of frogs and toads in Vietnam, many of which are highly threatened yet remain incredibly poorly known. Amphibians are under increasing threat from habitat loss, wildlife trade, climate change and deadly diseases.
9-2-20 Sea anemones grow more tentacles when they have plenty of food to eat
The number of tentacles that sea anemones grow isn’t set genetically. Instead it depends on how much they have to eat. If the same were true for people, it would mean that the more we ate, the more arms and legs we would grow, says Aissam Ikmi at the European Molecular Biology Laboratory in Heidelberg, Germany. In animals, both body shape and size are usually genetically determined. There are only a few known exceptions, such as Galapagos marine iguanas, which shrink by as much as 20 per cent during bad years. The iguanas don’t just lose fat, they reabsorb bone tissue. Now Ikmi’s team has studied 1000 polyps of the sea anemone Nematostella vectensis. The researchers found that the number of tentacles they have is determined by the amount the anemones eat. The growth of new tentacles can continue throughout adulthood if enough food is available. It isn’t just a matter of size, says Ikmi. The emergence of new tentacles is related to the relative change in an individual’s growth, rather than their absolute size. “You can find smaller anemones in a culture dish that have more tentacles than larger polyps.”
9-2-20 Honeybee venom 'kills some breast cancer cells'
Australian scientists say the venom from honeybees has been found to destroy aggressive breast cancer cells in a lab setting. The venom - and a compound in it called melittin - were used against two cancer types which are hard to treat: triple-negative and HER2-enriched. The discovery has been described as "exciting", but scientists caution that further testing is needed. Breast cancer is the most common cancer affecting women around the world. While there are thousands of chemical compounds which can fight cancer cells in a lab setting, scientists say there are few which can be produced as treatment for humans. Bee venom has previously been found to have anti-cancer properties for other types of cancer such as melanoma. The study by the Harry Perkins Institute of Medical Research in Western Australia was published in Nature Precision Oncology, a peer-reviewed journal. It tested venom from over 300 honeybees and bumblebees. The honeybee extracts were found to be "extremely potent", said Ciara Duffy, a 25-year-old PhD researcher who led the study. One concentration of the venom was found to kill cancer cells within an hour, with minimal harm to the other cells. But the toxicity increased for other dosage levels. The researchers also found the melittin compound on its own was effective in "shutting down" or disrupting cancer cell growth. While melittin naturally occurs in honeybee venom, it can also be synthetically produced. Traditionally, triple-negative breast cancer - one of the most aggressive types - has been treated with surgery, radiotherapy and chemotherapy. It accounts for 10-15% of breast cancers. On Wednesday, Western Australia's chief scientist described the research as "incredibly exciting". "Significantly, this study demonstrates how melittin interferes with signalling pathways within breast cancer cells to reduce cell replication," said Prof Peter Klinken. "It provides another wonderful example of where compounds in nature can be used to treat human diseases."
9-2-20 Honeybees are able to calculate probability and use it to find food
Honeybees can calculate probability, but it seems they don’t use it the same way we tend to. Andrew Barron at Macquarie University in Sydney, Australia, and his colleagues trained 20 honeybees to associate the colours of artificial flowers with the likelihood of obtaining sweet water. Over multiple sessions, they presented the bees with five colours in various combinations of two colours at a time. Each colour was ranked one to five. For each pair, only the higher-ranking colour dispensed sweetened water. The researchers then tested the bees on a combination they hadn’t seen yet: the second and fourth-ranking colours, representing odds of getting sweetened water of 66 and 33 per cent, respectively. You might think the best strategy for obtaining the treat would be to only visit flowers with the highest odds of delivering, but the bees did something different, says Barron. They matched the proportion of visits with the probability of getting sweet water, so for flowers with 66 per cent odds of sugar, they visited them roughly two-thirds of the time. This is known as probability matching. While that yields less sugar overall in the experiment than visiting the colour with the higher odds every time, it is a strategy that works better in a bee’s natural environment, says Zack Ellerby at the University of Nottingham, UK. With many bees competing for the same flowers with limited nectar, and the possibility of odds changing over time, this can be the optimal strategy, he says. “Ecologically, when information is uncertain and when gathering information has a cost, then probability matching is the best thing to do,” says Barron. “That’s what the bees did.” Humans tend to go for the highest odds in situations where probabilities seem to be fixed, such as a casino. The same might be true for bees; if they thought the odds for each colour were permanent, they might adjust their strategy, says Richard Mann at the University of Leeds, UK.
9-2-20 Flamboyant cuttlefish save their bright patterns for flirting, fighting and fleeing
Video footage exposes elaborate mating and defense mechanisms of the charismatic cephalopod. Don’t let the name fool you. Flamboyant cuttlefish (Metasepia pfefferi) look anything but flashy most of the time. Images and videos of the marine mollusks flashing bright purple and yellow hues litter the internet, perpetuating the idea that these animals are constantly putting on a show in the wild. But a new study proves just the opposite: Flamboyant cuttlefish spend most of their time looking like a pile of mud. “These animals have superb camouflage,” says Roger Hanlon, a marine biologist at the Marine Biological Laboratory in Woods Hole, Mass. Specialized cells and structures in their skin allow the animals to instantly morph into ostentatious patterns, as well as blend in. Keen to see how the animals balanced flamboyance with camo in nature, Hanlon organized two field studies in a cuttlefish habitat off the coast of North Sulawesi, Indonesia. Citizen scientist divers scouted the Lembeh Strait area over eight days in 2002 and again for 11 days in 2019, being careful to eavesdrop without disturbing the animals. Video footage collected by the team now reveals intimate details of the species’ mating practices and defensive behaviors as well as what the animals do in their downtime. Hanlon and Gwendolyn McManus, a marine biology student at Northeastern University in Boston, describe the results in the August Journal of Experimental Marine Biology and Ecology. The solitary species slowly ambles along the seafloor, foraging in a drab region of mud and sand between coral reefs. “It’s like a moonscape or a desert,” says Hanlon. Flamboyant cuttlefish take on the color and texture of their muddy seafloor backdrop and masquerade as a lump of sand or a rock. Like some other cephalopods, these cuttlefish spend most of their time incognito, reserving their displays for special occasions: confusing a predator, courting a mate and sparring with rival suitors.