1-31-20 Wisbech bees killed by 'morons' in hive attack
Two vandals branded "braindead morons" have been captured on CCTV attacking the hives of endangered bees. Conservationists believe as many as 10,000 rare bees may have died in the attack at Wisbech Castle, Cambridgeshire. The hives were established in the castle grounds last July in a bid to boost numbers of British black bees. A police spokeswoman called the attack a "cruel, unprovoked and completely unnecessary act of violence." CCTV footage, captured at about 05:15 GMT on 8 January, showed two people breaking into the castle grounds and lifting the lids off the hives, before kicking them and attacking the bees inside with sticks, police said. Steve Tierney, a councillor who chairs the Wisbech Castle Project, said on Facebook that the castle had been targeted by vandals before, but that "ridiculous and counterproductive heritage rules" prevented stronger security measures, such as wall spikes and anti-climb paint. Describing the culprits as "braindead morons", he said: "We had to make sure the bees were settled, and they've been doing well - but importantly they cannot be disturbed over the winter months. "These two people scaled the wall and went through black bin bags before smashing the lid off one of the hives. "They ran off and returned, setting about smashing them up. They may have been stung and came back for revenge." PC Kirsty Hulley, of Cambridgeshire Police, said castle staff were "devastated" by the attack. "They estimate as many as 10,000 rare bees have died, but are unable to check properly until March as further exposure to the cold air would kill the remaining bees. "It will cost the museum around £2,000 to restart the project in the spring." The native black bee was once considered to be extinct in Britain, but is hardier and darker than its European cousin, according to the Bee Improvement and Bee Breeders Association (BIBBA).
1-31-20 Engineered honeybee gut bacteria trick attackers into self-destructing
Special microbes mount steady gene-silencing attacks on mites or viruses. Deadly, fat-sucking mites and wing-wrecking viruses, take note. Specially engineered gut microbes can defend honeybees by tricking their enemies into self-destruction. Rod-shaped Snodgrassella bacteria, common in bee guts, were engineered to release double-stranded RNA molecules that dial down gene activity in a mite or virus. The pest then sabotages itself by shutting down some of its own vital genes. This strategy highjacks a natural biological process called RNA interference, or RNAi (SN: 10/4/06). The gut bacteria churning out this targeted disinformation work “something like a living vaccine,” says microbiologist Sean Leonard of the University of Texas at Austin. The RNA’s targeted approach intrigues scientists interested in fighting pests or other problems while minimizing the chances of hurting innocent bystanders. Earlier work shows that directly dosing bees with the customized RNA also can work, Leonard says, but the stuff is expensive to make and degrades rapidly. A gut microbe, however, can keep making the RNA, replenishing the supply. In a simplified test, Leonard and colleagues targeted two of the big threats to honeybees in North America: fat-sucking, parasitic Varroa mites and the deformed wing virus that those mites spread among bees (SN: 1/18/19). In a setup with just young bees, the engineered gut microbes helped protect the bees, the scientists report in the Jan. 31 Science. For the mite test, the researchers tracked fates of the pests. (Collecting mites to spread among experimental bees is easy, Leonard says. Just find infested bees and dust them with powdered sugar. Mites drop off in an arthropod shower.) Mites were about 70 percent more likely to die within 10 days when feeding on bees with the booby-trapped gut microbes.
1-30-20 Genetically modified microbiome could protect honeybees from disease
Bacteria from the microbiome of honeybees have been genetically modified to protect the insects against lethal infections, which could help with the recovery of hives. European honeybees (Apis mellifera) are vital pollinators, but numerous factors such as disease and pests are slashing their numbers. A major concern for most bee species is colony collapse disorder, a global phenomenon that has wiped out large numbers of hives in recent years. Sean Leonard and his colleagues at the University of Texas at Austin used a technique called RNA interference (RNAi) to tackle two of the biggest global killers of bees: parasitic varroa mites and deformed wing virus (DWV). Both DWV and varroosis – the disease caused by the mites – are closely linked to colony collapse. The team engineered a bee gut bacterium called Snodgrassella alvi, a normal part of the bee microbiome, to express double-stranded RNA targeting either the DWV genome or essential genes in varroa. Many organisms naturally respond to such strands by switching off genes with complementary sequences, making it useful for gene editing. Though the RNA can be injected into the bees directly, a large amount of it would need to be made. This is expensive and “you can’t inject 80,000 individual bees”, says Leonard, which is about the number in a hive. Instead, his team dunked 980 honeybees in a sugar solution containing the engineered S. alvi. The bees then ingest the bacteria when they clean the solution off each other. When a bee encounters the virus, its RNAi response is triggered to switch off the viral genes, while mites feeding on the bees can take up the RNA and die. The team found that in bees infected with DWV, those with an engineered microbiome had about a 40 per cent survival rate after 10 days compared with around 25 per cent for control bees. Mites also died more quickly when feeding on bees with engineered microbiomes, reducing the risk of varroosis.
1-29-20 Cyborg jellyfish that swim at triple speed could help protect oceans
Cyborg jellyfish could help in the fight against climate change by monitoring the state of the ocean. As a bonus, they also swim nearly three times faster than normal jellyfish. John Dabiri at Stanford University and his colleagues embedded electronics into live jellyfish so that they could be remote-controlled. Jellyfish are one of the most efficient swimmers in the world. Dabiri’s team had spent years trying to replicate their abilities in robots, but couldn’t do so. “It wasn’t very energy efficient, so we turned to utilising the jellyfish themselves,” he says. Normally, jellyfish swim by squeezing their bodies in and out to produce water jets that propel them forward. Dabiri’s electronics generate an electrical current which stimulates muscle contractions, producing the same effect, but 2.8 times faster. The system is controlled wirelessly and for now only allows the researchers to prompt forward motion – the jellyfish decides the direction of travel. Jellyfish don’t have pain receptors and Dabiri says the electronics were designed to be easily removed. Dabiri hopes to attach sensors to the jellyfish so that they can easily measure several aspects of the ocean like oxygen content and temperature. Increasing the speed of the jellyfish means that measurements at various depths or locations can be done more quickly, and strong ocean currents will have less of an effect on the trajectory of the animals. “These jellyfish could help us understand how the vertical profile of oxygen is changing in an environment. If we had a large number of sensors in the water, we could make those measurements at a high resolution very easily. This would give us data to validate our models of ocean climate,” he says.
1-29-20 Male moths genetically modified to kill females released in the wild
Genetically modified male diamondback moths designed to wipe out pest populations have been released in New York state. The field trial shows that these GM moths, whose female offspring die soon after hatching, could help control this major crop pest. Oxitec, the British biotechnology company behind the trial, has already carried out field trials of this method for controlling mosquitoes that spread diseases such as dengue. However, the moth field trial is the first for a crop pest, the company says. The larvae of the diamondback moth (Plutella xylostella) eat the leaves of brassica plants such as cabbage, kale, broccoli and oilseed rape (canola). The moths are a major pest worldwide, causing damage estimated at $5 billion a year. To create its GM moths, Oxitec added two genes to moths that are still susceptible to pesticides. One gene simply codes for a red fluorescent protein, so the insects can easily be identified in the wild. The other gene kills larvae soon after they hatch – but it switches on only in females. When male GM moths mate with wild females, all the female offspring die, but the males survive and pass the lethal gene on to their offspring. Because half the offspring of the GM males die each generation, the lethal gene should disappear after just a few generations. To continue to suppress wild populations, more GM males would need to be released. In field trials in August and September 2017 at the Cornell University Agricultural Experiment Station in New York, between 1000 and 2500 males were released on six separate occasions. The researchers then recaptured some of the moths to confirm that they survived in the wild. They say the moths should be as competitive with wild male moths in mating with females as they were in lab trials done in the US and UK.
1-28-20 How pandas use their heads as a kind of extra limb for climbing
Short legs on a chubby body demand a work-around when it comes to getting up a tree. Pandas really use their heads to climb. As the pudgy, short-legged bear climbs, it presses its head briefly against the tree trunk again and again, physicist Andrew Schulz said January 4 at the annual meeting of the Society for Integrative and Comparative Biology. The head serves as a make-do extra paw, first pressed against one side of the tree and then against the other. This extra pressure helps the bear hold on as it releases and raises an actual paw. Schulz knows of similar behavior only in newborn kangaroos, which use their heads to help haul themselves to their mother’s pouch for the first time. Head moves make sense for panda proportions, said Schulz, speaking for a research collaboration between his university, Georgia Tech in Atlanta, and China’s Chengdu Research Base of Giant Panda Breeding. Pandas have the shortest leg-to-body ratio among the world’s eight living bear species. “I like to call them Corgi bears,” he says. How pandas, or any other big mammals, climb hasn’t gotten the analytic attention that techniques of squirrels and other small animals have, Schulz said. Yet rushing up a tree trunk can be a lifesaving move in the wild for pandas attacked by feral dogs. Chengdu researcher James Ayala conceived the climbing study to get the first quantitative data on emergency escape skills in captive-bred youngsters. Such information helps the Chengdu researchers judge young pandas’ chances of surviving in the wild. For this study, the Chengdu staff built a panda climbing gym: four bark-stripped tree trunks, each a different diameter, holding up a high platform. Researchers videotaped eight young pandas, all at least a year old. The animals had grown beyond the waddling fluffball stage and were basically young teenagers with a bit of growing, and sometimes a lot of learning, left to do.
1-28-20 Endangered cheetahs can return to Indian forests - court
India's top court has said cheetahs can be reintroduced in the country, 70 years after they were wiped out. Responding to a plea by the government, the Supreme Court said African cheetahs could be introduced to the wild in a "carefully chosen location". Cheetahs are an endangered species, according to the Convention on International Trade in Endangered Species (Cites). Only 7,100 cheetahs are left in the wild, almost all of them in Africa. The Asiatic cheetah, which once roamed parts of India, is now only found in Iran, where there are thought to be about 50 left. India's Supreme Court said the animal would have to be introduced on an experimental basis to find out if it could adapt to Indian conditions. Studies show that at least 200 cheetahs were killed in India, largely by sheep and goat herders, during the colonial period. It is the only large mammal to become extinct after the country gained independence in 1947. India's former environment minister Jairam Ramesh welcomed the decision to reintroduce the animal. For more than a decade, wildlife officials, cheetah experts and conservationists from all over the world have discussed the reintroduction of the spotted big cat to India and have agreed that there is a strong case for it. But leading conservationists have harboured doubts about the plan. They fear that in its haste to bring back the cheetah, India will end up housing the animals in semi-captive conditions in huge, secured open air zoos rather than allowing them to live free. They add that without restoring habitat and prey base, and given the high chances of a man-animal conflict, viable cheetah populations cannot be established. They have also pointed to India's chequered record of reintroducing animals to the wild. Lions were reintroduced in the Chandraprabha sanctuary in northern Uttar Pradesh state in the 1950s, but were then poached out of existence.
1-27-20 Albatrosses strapped with sensors help spy on illegal fishing boats
Birds carrying radar sensors have been used to spy on fishing boats, revealing that a quarter of vessels in the Indian Ocean are operating illegally. Globally, illegal fishing is estimated to cost £17.6 billion a year, but satellite monitoring can be costly, sometimes slow and can miss boats. An international team decided to give flight to a pioneering alternative: strapping sensors to 169 albatrosses and releasing them in the south of the Indian Ocean. The birds can travel vast distances and are attracted to fishing vessels. The researchers attached sensors that could pick up a boat’s use of radar from about 30 kilometres away. Between December 2018 and June 2019, they detected a total of 353 fishing boats in the region. Of those operating in countries’ exclusive economic zones (EEZs), where vessels have to declare fishing, 25.8 per cent had their Automatic Identification Systems – used for avoiding collisions and allowing authorities to track them – switched off. Such behaviour is often a sign of illegal fishing. In international waters, fishing isn’t illegal but should be declared. There, the birds revealed that 36.9 per cent of vessels had the system turned off. Henri Weimerskirch at the French National Centre for Scientific Research (CNRS) says the success of the project shows it is a cheap form of surveillance that could complement satellite monitoring. “We have shown that it is possible,” he says. The birds could even be used as part of enforcement efforts in conjunction with navies, because they relay data in real-time, he says. But to direct them to spy on certain areas would require expert knowledge from ornithologists. And improvements in satellites may do away with the need for bird spies.
1-26-20 Wild horses in the US are being shot with contraceptive darts
Shooting wild horses with contraceptive darts may help curb their numbers in parts of the US where their populations are ballooning out of control. Horses were reintroduced to the US by the Spanish in the 16th century, after native North American horses went extinct about 10,000 years ago. Lacking natural predators, they have since spread across the rangelands in the western US. More than 70,000 wild horses now occupy public rangelands, about 45,000 more than the limit set by the US government to ensure there is enough food and water to share with livestock and native wildlife. The US Bureau of Land Management manages excess horses by adopting out a small number and housing the rest in long-term holding facilities. There are currently almost 50,000 horses being held, but these facilities are becoming overwhelmed and many scientists think they are cruel. “Horses form these tight social bonds and then they’re torn apart and shoved in these really crowded conditions and spend the rest of their lives there,” says Tiana Pirtle at the University of Tasmania in Australia, where authorities are also struggling to manage a booming wild horse population. Since the 1980s, the US has been experimenting with using contraception to reduce wild horse numbers. However, most contraceptives developed to date only last a short time or have to be injected by hand, making them unsuitable for areas where horses inhabit rough, hard-to-access terrain. Now, Allen Rutberg at Tufts University in Massachusetts and his colleagues have shown that shooting wild horses with contraceptive darts is effective in reducing births. In the study, horses in rugged areas were targeted by luring them with baits and shooting them with darts containing a long-acting contraceptive called porcine zona pellucida-22 (PZP-22).
1-26-20 The tiger ‘gift’ that horrified Polish rescuers
Nine emaciated and distressed tigers transported from Italy to the Poland-Belarus border are safe now, but the case exposed a cruel, shadowy trade in exotic animals destined for Asia. The discovery last October shocked Ewa Zgrabczynska, director of Poznan Zoo in Poland, which is looking after four of them. The other five were taken in by an animal welfare centre called Primadomus, near Alicante in southern Spain. The tigers were starving, thirsty and filthy after a 2,000km (1,243-mile) road journey to Belarus. A tenth one did not survive. The survival of the other nine was just good luck: the Belarus border guards were suspicious about the animal transporter's paperwork and refused to let it through. The animal transport lorry, driven by two Italians, was totally unsuited for the tigers crammed in there: it was the type used for carrying horses or cattle. BBC Russian has established that they were bound for an unlicensed zoo in distant Dagestan, in Russia's Caucasus. But the question is: did the final customer want them dead or alive? Poznan Zoo described its horror on Facebook: "Our employees arrived at the scene to discover a real nightmare. The tigers have excrement stuck to their fur and are tired and hungry. Our veterinarian says their condition is appalling." Ewa Zgrabczynska doubted that any circus director or zoo manager would subject animals to such conditions - after all, their animals' health is key to their livelihood. "I think this was a deadly journey for the tigers. The price of a tiger on the black market can be very high and animal parts are even more expensive than a live animal," she said. In the documentation the tigers were described as a "gift" for a zoo called Skazka ("fairy tale" in English) in Derbent, Dagestan. Ms Zgrabczynska believes the "gift" description was a ruse to get round Cites - the Convention on International Trade in Endangered Species. Tigers are among the many species that Cites is designed to protect.
1-24-20 The parrots who look out for their pals
Researchers in Germany have observed parrots carrying out seemingly “selfless” acts of kindness—behavior that has previously only been seen in humans and a few other primates. Désirée Brucks, a biologist at the Max Planck Institute for Ornithology, trained several African grey parrots to pass her small metal tokens when she held out her hand, in exchange for a walnut treat. She then placed two of the birds in adjacent clear-walled compartments with a small opening between them; one compartment also had a hole at the front. Brucks gave the tokens to one parrot, but only the other bird could reach her hand. Immediately, the parrot with the tokens started passing them through the opening to its neighbor, who could then exchange them for food. The first parrot carried on helping its feathered friend even though it received nothing in return. To make sure the birds weren’t just playing, Brucks blocked the hole at the front and didn’t hold out her hand—and the parrot passed far fewer tokens. This “prosocial” behavior isn’t apparent in all birds; when the experiment was repeated with blue-headed macaws, the birds only acted selfishly. It’s unclear why African greys have evolved to be helpful. But the study adds to a growing body of evidence that birds are smarter than their small brains suggest. “I think we have underestimated birds,” Brucks tells CNN.com. “We’ve been too focused on our close relations like primates.”
1-24-20 Locusts: UN calls for international help in East Africa
The UN has called for international help to fight huge swarms of desert locusts sweeping through east Africa. A spokesman for the UN's Food and Agricultural Organisation (FAO), called for aid to "avert any threats to food security, livelihoods, malnutrition". Ethiopia, Kenya and Somalia are all struggling with "unprecedented" and "devastating" swarms of the food-devouring insects, the FAO has said. The agency fears locust numbers could grow 500 times by June. Ethiopia and Somalia have not faced an infestation on this scale for 25 years, while Kenya has not seen a locust threat this size for 70 years, the FAO said earlier this week. South Sudan and Uganda are also at risk if the swarms continue to grow and spread. "The speed of the pests' spread and the size of the infestations are so far beyond the norm that they have stretched the capacities of local and national authorities to the limit," the FAO said. The only option left was "aerial control" - spraying insecticide from aircraft. The swarms have spread from Yemen across the Red Sea. Heavy rainfall at the end of 2019 created ideal conditions for the food-devouring insects to flourish. And the problem could get worse as the year goes on. Aside from growing numbers in east Africa, locusts have also been breeding in India, Iran and Pakistan, which could turn into swarms in the spring. Locusts can travel up to 150 kilometres (93 miles) in a day. Each adult insect can eat its own weight in food each day. A swarm the size of Paris could eat the same amount of food as half the population of France in a single day, an FAO fact sheet says. In November, the UN warned about the locust infestation in Ethiopia - saying that the creatures could spread into Ethiopia and Kenya if not dealt with. Some farmers in Ethiopia's Amhara region lost 100% of their crops.
1-24-20 Sparkly exoskeletons may help camouflage beetles from predators
Long thought to help insects stand out, iridescence may instead let some blend in. Iridescence sparkles across many branches of the tree of life, from dazzling ruby-throated hummingbirds to bright, metallic beetles. While ostentatious coloration can woo mates, scientists had assumed it also attracted predators. But new evidence suggests an unexpected benefit of iridescence — camouflage. Asian jewel beetles (Sternocera aequisignata) boast brilliantly iridescent exoskeletons, and the fact that both males and females share this trait suggests its importance outside of mating. To see if iridescence affected whether beetles were detected by hungry birds, behavior ecologist Karin Kjernsmo at the University of Bristol in England and colleagues pinned mealworm-stuffed iridescent beetle wing cases to forest leaves along with non-iridescent ones artificially colored blue, green, purple, rainbow or black. All 886 targets — iridescent and matte — represented the spectrum of colors in the iridescent shell, allowing researchers to disentangle the effects of individual colors from the ever-changing sparkle of iridescence. After two days, the iridescent “beetles” were less likely to have been attacked by birds than all the other colors, except black, researchers report January 23 in Current Biology. Birds “killed” 85 percent of purple and blue targets, but less than 60 percent of iridescent targets, Kjernsmo says. “It may not sound like much, but just imagine what a difference this would make over evolutionary time.” It’s unclear if birds had trouble seeing iridescence or were avoiding it, for example if they associated it with poisonous prey. But Kjernsmo suggests the rapidly changing colors could disrupt normal image-forming processes.
1-22-20 Collectors find plenty of bees but far fewer species than in the 1950s
A look at global insect collections suggests bee diversity has dropped sharply since the 1990s. Far fewer bee species are buzzing across Earth today, following a steep decline in bee diversity during the last three decades, according to an analysis of bee collections and observations going back a century. About half as many bee species are turning up in current collecting efforts for museums and other collections compared with in the 1950s, when surveys counted around 1,900 species a year, scientists report December 10 at bioRxiv.org. That high diversity in collections endured for several decades, but then began to plummet around the 1990s, likely reflecting a real drop in global bee diversity, according to the study, which is under peer review. “This is the first study suggesting that bee decline is a global process, and that the most significant changes have occurred in recent years,” says Margarita López-Uribe, a bee evolutionary ecologist at Penn State who was not part of the new research. The new work evaluates global trends in bee diversity since the 1920s by tapping the database of the Global Biodiversity Information Facility. This international data-sharing network holds what López-Uribe describes as “the most comprehensive dataset of insect collection records worldwide,” including photos of bees in the field and of museum specimens dating back to the 18th century. Previous bee studies have reported falling populations, but evidence has often been limited to Europe and North America. Numbers of western honeybees (Apis mellifera) have been decreasing in North America and Europe (SN: 6/20/19), for example, but have increased in Asia, Africa and South America. For bees overall, though, the global situation was unclear.
1-20-20 Man raised alongside chimps says it should never happen again
Nick Lehane's performance piece, Chimpanzee, in London for the first time, reveals how tragedy stalked the amazing achievement of raising chimps in human families The puppet, a life-sized female chimpanzee, is made out of wood, rope, carved hard foam and paper mâché. She gazes out at the audience from a raised platform and, through movement alone, weaves her tale. When she was young, she lived as part of a human family. Now she is incarcerated in a research laboratory, deprived of company, her mind slowly deteriorating. Rowan Magee, Andy Manjuck, and Emma Wiseman operate the chimpanzee, the sole actor in a puppet play running at the Barbican Centre in London. The play, Chimpanzee, by Brooklyn-based actor and puppeteer Nick Lehane, is a highlight of 2020’s London Mime. It is a moving story that is attracting attention from neurologists and cognitive scientists along with the usual performing-arts crowd. Lehane conceived the show after reading Next of Kin, a memoir by psychologist and primate researcher Roger Fouts. Fouts’s tales of experiments in fostering young chimpanzees in human homes had obvious dramatic potential. Then, as Lehane looked deeper, he discovered a much darker story. The Fouts family’s own chimps enjoyed a relatively comfortable life once they outgrew their human home. But other chimpanzees in similar programmes found themselves sold to research labs, living out almost inconceivably solitary lives of confinement and vivisection.Modern efforts to communicate with chimpanzees began in 1967 at the University of Nevada, Reno, when primatologists Allen and Beatrix Gardner set up a project to teach American Sign Language (ASL) to a chimp called Washoe. These experiments have so transformed our view of chimp culture that many of the original researchers are campaigning to end the practice of keeping primates in captivity. (It is still legal to keep primates as pets in the UK.)
1-19-20 Releasing rescued orangutans into the wild doesn’t boost populations
The number of Bornean orangutans is dwindling, and there is little evidence that efforts to relocate them from risky areas or rehabilitate those once held captive actually works to bolster their population. Between 2007 and 2017, about 1200 Bornean orangutans (Pongo pygmaeus) were released into natural forests in Kalimantan, the Indonesian part of the island of Borneo. Nearly 500 of those were formerly captive individuals nursed back to health before being released into the wild. But how many of these animals are still alive remains unclear. “Rescue centres do an important service by providing specialised care for a difficult-to-care-for species, but there is little publicly available evidence on the long-term survival of the reintroduced animals,” says Julie Sherman at Wildlife Impact in Oregon. Sherman and her team reviewed studies, news stories and publicly available data on conservation efforts to make these estimates. They also collected data from rescue centres, government agencies and zoos to determine the outcomes of relocation or rehabilitation for these great apes. The handful of cases where these animals were tracked for more than three years suggest that fewer than 30 per cent of the released animals may have survived. During the study period, at least 620 wild orangutans were also picked up outside protected areas in Kalimantan and released into a different wild site, mainly to prevent potential conflict with people. “The assumption translocation practitioners make is that since these are wild orangutans, they will survive anywhere in the wild,” says Sherman. Again, the fate of such animals is usually not monitored. The few studies that Sherman’s team found in which relocated orangutans were tracked suggest that most animals probably disappeared after release and may not have survived beyond a few years.
1-17-20 Cat owners
Cat owners, after a new study found evidence that cats will eat human flesh, including its owner’s corpse if there’s no other food.
1-17-20 Tortoise Adam
After helping save his species, Diego the giant—and remarkably frisky—tortoise is finally slowing down. Now more than 100 years old, Diego was shipped from San Diego Zoo to the Galapagos in 1976 to help repopulate the islands’ threatened Chelonoidis hoodensis tortoises. At the time, only 14 of the massive creatures (12 females and two males) lived on their native Española Island. Diego got straight to work, fathering more than 800 offspring at the captive-breeding program on the island of Santa Cruz. There are now some 2,000 of the giant tortoises, and Diego is retiring to Española. “There’s a feeling of happiness,” said park director Jorge Carrión, “of returning that tortoise to his natural state.”
1-17-20 A naturalist writes an homage to bird migration
A Season on the Wind shares observations of the passage of birds through northwestern Ohio. A tiny blackpoll warbler, a bird no heavier than a ballpoint pen, makes an epic journey each year. In fall, the bird flies some 10,000 kilometers from its breeding grounds in Alaska or Canada to its winter retreat in South America. In the spring, the bird undertakes the return trip. In his memoir A Season on the Wind, naturalist Kenn Kaufman shares his awe for the miraculous round-trip flight this warbler makes every year. A backdrop to the book is northwestern Ohio’s “Biggest Week in American Birding,” headquartered at Magee Marsh in Oak Harbor. As northbound birds like the blackpoll drop into the marshes that line Lake Erie’s southern shore in early May, so do the birders — who come to see the hundreds of migratory bird species that stop here to rest and feed every spring. Kaufman intertwines his personal reminiscences with stories of individual bird species and migration science. His observations are intensely personal, yet also offer insight into the shared experience of a global community of birders. Of the birders who flock from all over the world to Magee Marsh in spring, he writes, “I see people arriving here with mild curiosity and leaving with the spark of an intense, passionate interest.” His memoir reads as a love letter to bird migration, his adopted home of northwestern Ohio and his wife, Kimberly. Kaufman has authored a dozen popular guidebooks to the birds, insects and mammals of North America. In A Season on the Wind, he returns to the storytelling that won over readers of his classic 1997 memoir Kingbird Highway. That award-winning book told of his exploits hitchhiking around North America as a teenager in the 1970s in pursuit of a birding “big year” — competing with others to see the greatest number of species in a single calendar year.
1-16-20 We’ve seen wolf pups play fetch just like dogs for the first time
Fetching a thrown ball is one of the most quintessential dog behaviours, right up there with begging for scraps and tail wagging. But new research suggests that fetching may be older than dogs themselves, as some wolf pups also seem to enjoy the game. The first observations of wolf pups fetching balls for humans happened unexpectedly, says Christina Hansen Wheat at Stockholm University in Sweden. Hansen Wheat’s team studies the behavioural changes involved in domestication using dogs and wolves as a model. The team hand-reared wolf pups from three litters from the age of 10 days. When they were 8 weeks old, the team put the pups through a standardised series of tests to evaluate their behaviour. One of these tests was having an unfamiliar human toss a tennis ball across the room to see how much it captured the pup’s attention. Almost all of the pups from the 2014 and 2015 litters flatly ignored the ball. One gave it a passing glance. The next year, one pup shocked the scientists by not only chasing down the ball and snatching it up, but bringing it back to the human when coaxed. Hansen Wheat was watching from another room. “I literally got goosebumps,” she says, adding that dogs’ ability to interpret socially communicative behaviour from humans – like following a human’s cues to bring a ball back – has been considered a consequence of the domestication process. “Retrieving for a human has never before been shown in wolves,” says Hansen Wheat. In the end, three wolves from the 2016 litter fetched the balls, and one did it on all three trials of the test. Others played with the ball but wouldn’t return it. Hansen Wheat thinks the difference is likely to be rooted in the pups’ genetics, since the litters were brought up under identical conditions. Evan MacLean at the University of Arizona finds the ball retrieval particularly intriguing. “The first part – chasing, picking up in mouth – is largely within the predatory play repertoire,” says MacLean. “The returning with the object to the person is decidedly more dog-like.”
1-15-20 A parasite that makes mice unafraid of cats may quash other fears too
Toxoplasma gondii can mess with all sorts of mice behaviors, a new study shows. A parasite common in cats can eliminate infected mice’s fear of felines — a brain hijack that leads to a potentially fatal attraction. But this cat-related boldness (SN: 9/18/13) isn’t the whole story. Once in the brain, the single-celled parasite Toxoplasma gondii makes mice reckless in all sorts of dangerous scenarios, researchers write January 14 in Cell Reports. Infected mice spent more time in areas that were out in the open, exposed places that uninfected mice usually avoid. Infected mice also prodded an experimenter’s hand inside a cage — an intrusion that drove uninfected mice to the other side of the cage. T. gondii–infected mice were even unfazed by an anesthetized rat, a mouse predator, the researchers from the University of Geneva and colleagues found. And infected mice spent more time than uninfected mice exploring the scents of foxes and relatively harmless guinea pigs. The extent of mice’s infections, measured by the load of parasite cysts in the brain, seemed to track with the behavior changes, the researchers report. The parasite needs to get into the guts of cats to sexually reproduce. Other animals can become infected by ingesting T. gondii through direct or indirect contact with cat feces. The parasite can then spread throughout the body and ultimately form cysts in the brain. People can become infected with T. gondii, though usually not as severely as mice. Some studies have hinted, however, at links between the parasite and human behaviors such as inattention and suicide, as well as mental disorders such as schizophrenia.
1-13-20 Secrets of '1,000-year-old trees' unlocked
Scientists have discovered the secret of how the ginkgo tree can live for more than 1,000 years. A study found the tree makes protective chemicals that fend off diseases and drought. And, unlike many other plants, its genes are not programmed to trigger inexorable decline when its youth is over. The ginkgo can be found in parks and gardens across the world, but is on the brink of extinction in the wild. "The secret is maintaining a really healthy defence system and being a species that does not have a pre-determined senescence (ageing) programme," said Richard Dixon of the University of North Texas, Denton. "As ginkgo trees age, they show no evidence of weakening their ability to defend themselves from stresses." Researchers in the US and China studied ginkgo trees aged 15 to 667, extracting tree-rings and analysing cells, bark, leaves and seeds. They found both young and old trees produce protective chemicals to fight off stresses caused by pathogens or drought. These include anti-oxidants, antimicrobials and plant hormones that protect against drought and other environmental stressors. Genetic studies showed that genes related to ageing didn't automatically switch on at a certain point in time as in other plants, such as grasses and annuals. Thus, while a tree that has lived for centuries might appear dilapidated due to frost damage or lightning strikes, all the processes needed for healthy growth are still functioning. Dr Dixon suspects the picture will be similar in other long-lived trees, such as the giant redwood, which has wood "packed with antimicrobial chemicals". "Hopefully our study will encourage others to dig deeper into what appear to be the important features for longevity in ginkgo and other long-lived trees," he said.Commenting on the study, Mark Gush, head of horticultural and environmental science at the RHS (Royal Horticultural Society), said the oldest living tree in the world - a Bristlecone pine (Pinus longaeva) - is estimated to be more than 4,800 years old.
1-13-20 Australian fires have incinerated the habitats of up to 100 threatened species
Scientists warn of an ecological catastrophe as crucial habitats of rare plants and animals burn. Until last week, the Kangaroo Island glossy black cockatoo was one of Australia’s conservation success stories. Thanks to a recovery program that began in 1995, its wild population increased from 150 to 400, and its status was downgraded from critically endangered to endangered. Now it’s part of an unfolding horror story. Fires have raged across nearly 50 percent of Kangaroo Island, a 4,400-square-kilometer isle off the coast of the state of South Australia, destroying the habitat of the great majority of the birds. It’s unclear how many glossy black cockatoos (Calyptorhynchus lathami halmaturinus) survived. For those that escaped the flames, food may be scarce; it eats the seeds of single tree species in its habitat, the drooping she oak. Many years of hard work have gone up in smoke and “it’s a big step backwards for the recovery team,” says Daniella Teixeira, a conservation biologist at the University of Queensland in Brisbane, Australia, who has studied and worked to protect the birds for the last four years. Even if just a quarter of the population has been killed, the subspecies could end up back on the critically endangered list, she says. Similar stories are playing out across Australia, where, as of January 12, months of wildfires had burned nearly 11 million hectares — an area larger than the nation of Guatemala. More than 2,200 homes have gone up in flames and 29 people have been killed, and there are still two months of bushfire season left to go. Already, the toll on animals and plants, many of which are evolutionarily unique and endemic to the continent, is mind-boggling.
1-11-20 Mummified skin suggests duck-billed dinosaurs were grey like elephants
A mummified dinosaur has skin so well preserved that the remains of blood vessels and pigment can be seen, and analysis of the pigment suggests that the animal had dark grey skin. However, it is possible that the dinosaur’s skin contained other pigments that haven’t been preserved. While paintings of dinosaurs often show them with brightly coloured skin, we actually know very little about their true colours. Most dinosaurs are only known from bones and teeth, and in the few cases where their skin has been preserved, it has rarely been possible to detect pigment molecules. We know more about the colour of early birds because feathers are more frequently conserved. Matteo Fabbri and Jasmina Wiemann at Yale University in New Haven, Connecticut, and their colleagues studied a mummified hadrosaur, or duck-billed dinosaur, which had preserved skin on its flank. When they examined thin slices of the skin, they discovered globules that look like preserved cells and fragments of blood vessels. The skin was unusually thin for such a large animal, and surprisingly similar to that of birds – even though hadrosaurs weren’t that closely related to them. Wiemann, an expert on fossilised molecules who previously found that some dinosaurs laid blue eggs, chemically analysed the material. She found that some original molecules were preserved, in degraded form. “Until now, we saw skin from a morphological perspective, but now we know these kinds of fossils also contain molecular information,” says Fabbri. Crucially, the skin contained small granules containing eumelanin: a pigment that creates a dark grey colour. If eumelanin was the only pigment the hadrosaur possessed, it would have had grey skin like that of a rhinoceros or elephant.
1-11-20 Sri Lanka elephants: 'Record number' of deaths in 2019
A record number of elephants - 361 - have died in Sri Lanka during 2019, environmental groups say. It is highest figure of elephant deaths to be reported since Sri Lanka became independent in 1948, conservationists said. Most were killed by people. There are an estimated 7,500 wild elephants in Sri Lanka. Killing them is illegal, but the animals often come into conflict with rural communities. Elephants are revered in Sri Lanka but some farmers view them as pests. Sajeewa Chamikara, an environmentalist from the Movement for Land and Agricultural Reform, told the BBC that some 85% of elephant deaths last year may have been caused by human activity. He said communities had used electric fences, poison and explosives concealed as food to kill the animals. In September, officials said they suspected seven elephants found dead in a reserve were poisoned by local residents for destroying crops. BBC World Service South Asia editor Anbarasan Ethirajan says the expansion of villages and farms in Sri Lanka has contributed to dwindling supplies of food and water for the animals. Officials have promised to work to resolve the conflict by putting fences between elephant habitats and rural communities. But Mr Chamikara said the government needed to do more to improve the quality of protected areas, such as tackling the issue of invasive plants which grow over grasslands that feed the elephants. "Our development plan is not eco-friendly. We need a sustainable development plan," he said. Trains are responsible for killing some wild elephants during their migration. Others die of natural causes, he said. Dozens of elephants are kept in captivity in Sri Lanka to raise income from tourists, while others are forced to march at local festivals.
1-11-20 Tortoise with species-saving sex drive returns to Galápagos
A giant tortoise whose legendary libido has been credited with saving his species from extinction is to return to the wild on the Galápagos Islands. Diego was among 14 male tortoises selected to take part in a breeding programme on Santa Cruz Island. The programme has been a success, producing more than 2,000 giant tortoises since it began in the 1960s. Diego's sex drive was said to be one of the main reasons. The 100-year-old tortoise has fathered hundreds of progeny, around 800 by some estimates. The programme has now finished, and Diego will be returned to his native island of Española in March, the Galápagos National Parks service (PNG) said. He will join a 1,800-strong tortoise population, at least 40% of which park rangers believe he has fathered. "He's contributed a large percentage to the lineage that we are returning to Española," Jorge Carrion, the park's director, told AFP news agency. "There's a feeling of happiness to have the possibility of returning that tortoise to his natural state." The park service believes Diego was taken from the Galápagos 80 years ago by a scientific expedition. Around 50 years ago, there were only two males and 12 females of Diego's species alive on Espanola. To save his species, Chelonoidis hoodensis, Diego was brought in from California's San Diego Zoo. Diego is currently in quarantine before his triumphant return to Española, considered one of the oldest parts of the Galápagos. The Galápagos Islands, 906km (563 miles) west of continental Ecuador, are a Unesco World Heritage site renowned worldwide for their unique array of plants and wildlife. The indigenous species found on the Galápagos, including iguanas and tortoises, played a key role in the development of Charles Darwin's Theory of Evolution.
1-11-20 An ecologist on the future of Australia's wildlife
Australian firefighters used a break from searing temperatures last Tuesday to strengthen containment lines around huge wildfires as the financial and environmental costs of the crisis mounted. More than 25.5 million acres of land — an area the size of South Korea — have been razed by bushfires across the country in recent weeks, according to the latest data, with the southeast particularly hard hit. Imagery posted online from the Himawari 8 Japanese satellite and NASA's Earth Observatory showed plumes of smoke from the fires reaching as far as South America. The devastating bushfires are exacting a heavy human toll — at least 24 people have died since September. Wild animals have fared much worse. The University of Sydney ecologist Chris Dickman stunned people recently with his estimate that 480 million animals have been injured or killed in Australia's bushfires. A few weeks later, the fires have spread even farther, and he's updated the impact to include 1 billion animals. "The 480 million estimate was made a couple of weeks ago, and the fires have now burnt over a large area of the further country. That means over 800 million mammals, birds, and reptiles have been affected by the fires. Australia-wide, it's probably over a billion," Dickman said. "I think there's nothing quite to compare with the devastation that's going on over such a large area so quickly. It's a monstrous event in terms of geography and the number of individual animals affected." Dickman spoke to The World's Patrick Winn about the conditions animals in Australia are now facing. Patrick Winn: Give us a better idea, not to be morbid, but how these creatures are dying. Are we talking about actually being burned to death? Smoke inhalation or starvation? What are the different scenarios here? Chris Dickman: Death by flames is the most obvious. Some of the images of koalas bring home what that's like most vividly. At the fire front, firefighters have talked about the shrieks of koalas, just screams of pain as they die. It's just horrendous. For others, perhaps those in tree hollows or perhaps those who haven't been able to go too deeply under the ground, smoke inhalation will be a real problem. For the others, it's probably a slower demise. For the species that go underground and then reemerge after the fires have gone through, there's really nothing except ash on the surface. So, it's very difficult to find resources.
1-10-20 Puffins that use tools
Puffins have been spotted scratching themselves with sticks—the first time wild seabirds have been observed using tools. Researchers saw two Atlantic puffins, one in Wales and one on an Icelandic island, using sticks as grooming devices. In footage from Iceland, a puffin waddles toward the camera, grabs a stick with its beak, and scratches itself under its chest with the piece of wood. The bird then drops the stick rather than taking it home to its nest. Researchers say the puffin was likely trying to knock off ticks, which plague seabird populations. Other birds—including crows and parrots—have been spotted using tools, but never for anything other than acquiring hard-to-reach food. Only primates and elephants are known to use tools for other tasks. Study author Annette Fayet says her findings suggest we may have underestimated birds’ cognitive abilities. “Many more species may also be using tools,” she tells CNN.com, “but we simply haven’t observed them yet.”
1-10-20 A ‘bonanza’ of new bird species was found on remote Indonesian islands
Discovering 10 new songbird species and subspecies at once is extremely rare in the 21st century. It’s a veritable bevy of birds: Ten songbirds hailing from a cluster of small Indonesian islands near Sulawesi have officially joined the scientific record. Typically, only five or six new bird species are described each year across the globe. So the discovery of five new species and five new subspecies, characterized in the Jan. 10 issue of Science, marks a remarkable expansion of bird biodiversity, considering that birds are among the most comprehensively categorized animal groups. Evolutionary biologist Frank Rheindt at the National University of Singapore had an inkling these remote, forested islands with mountain highlands held an unrecognized wealth of bird life. The islands — Taliabu, Peleng and the Togian group — sit in the middle of Wallacea, a geologically and biologically complex region of Southeast Asia. But deep waters separate the islands from the nearest large landmass of Sulawesi, limiting opportunities for many animals to intermingle across the region. This includes tropical forest birds, which rarely venture out from the shady cover of the forest, let alone fly kilometers over open ocean. In searching for new species, “it’s very important to pick deep-sea islands,” Rheindt says. “Those are the ones that are likely to have endemic species that are not shared with other landmasses.” Even more encouraging, the islands’ interior highlands hadn’t received much attention from European explorers or naturalists, who instead had focused on the coasts, he says. Other researchers in the 1990s had reported what appeared to be distinct songbird species on the islands. But they hadn’t collected specimens, nor formally described what they’d found.
1-9-20 Scientists have discovered five new species of songbird in Indonesia
Five species of songbird and five more subspecies have been discovered by scientists for the first time in mountainous areas of Indonesia. The newly described bird species, named after the islands where they were discovered, are the Peleng fantail, the Peleng leaf warbler, the Taliabu grasshopper warbler, the Taliabu myzomela and the Taliabu leaf warbler. They are small songbirds characterised by their unique and unusual sounds. Discovering this many new species in one go from such a small area “really is quite astounding”, says Simon Mitchell at the University of Kent, UK, who wasn’t involved with the work. Some of the more colourful species were already known to locals, but others, such as the Taliabu grasshopper warbler, had been missed because they sound more like insects than birds. “I was definitely very surprised,” says Frank Rheindt at the National University of Singapore, who discovered the birds in collaboration with Dewi Prawiradilaga at the Indonesian Institute of Sciences and colleagues. Rheindt says he first heard some of the songbirds hours or even days before he finally saw them. This was the case for the Taliabu grasshopper warbler, which, according to Rheindt, sounds like a cricket. “When I heard it, I was aware that it was a type of grasshopper warbler, but it sounded very different from the ones that I knew,” says Rheindt. “I had a hunch that this would be a new species, but it took me a week or more to see them for the first time.” “Some of these newly described bird species and subspecies are already endangered,” says Rheindt. The Taliabu grasshopper warbler is particularly threatened, as its habitat in the mountaintops of Taliabu is shrinking. But the discovery of these birds means efforts can now begin to protect them. “In order to protect species, we need to know of their existence,” says Per Alström at Uppsala University in Sweden. Today, many species probably go extinct before we even become aware of them, says Alström.
1-9-20 African grey parrots are smart enough to help a bird in need
African grey parrots are not only really smart, they are helpful too. They are the first bird species to pass a test that requires them both to understand when another animal needs help and to actually give assistance.. Besides humans, only bonobos and orangutans have passed this test, says Désirée Brucks at the Ludwig Maximilian University of Munich in Germany. Even chimps and gorillas have failed at it. Brucks and her colleague Auguste von Bayern first trained birds one at a time. Each was given a pile of tokens – small metal washers – and taught that they could exchange them for food by passing them to a researcher through a small hole in a clear screen. A month later, two birds were separated from each other and the researcher by clear screens. One bird was given a pile of tokens but the hole between it and the researcher was blocked. The other bird’s hole to the researcher was open but it had no tokens. There was a third hole in the screen between the two birds, allowing them to pass objects through, as shown above. Seven out of eight African grey parrots passed tokens through this third hole to birds without tokens, so those birds could swap them for food. They passed more tokens when the other bird was one they spend lots of time with – a “friend” – but still did it for birds they spend little time with. If there was no other bird, they didn’t pass tokens through the hole. And if both holes to the researcher were closed so neither bird could exchange tokens for food, those with tokens passed far fewer to the other bird. This test requires both intelligence and helpfulness, says Brucks. “They need to understand that the other bird is in need of help.” The pair also tested blue-headed macaws, but found they didn’t help other macaws. In 2015, another team found that ravens didn’t help each other either.
1-8-20 The odd history of the mulberry tree's ties to silk, music and money
Mulberry, a book celebrating the marvellous tree, goes beyond its ancient links to silk production to explore its role in everything from the oldest banknotes to modern drugs. IN THE right hands, book series can be very satisfying. Reaktion Books has developed several over recent years. One of these is a delightful series called Botanical that aims to integrate the social, biological and historical contexts of a plant, tree or flower. It has provided excellent treatments of the yew, snowdrop, oak and primrose among some two dozen more. Chrysanthemum and Berries will appear later this year. Right now though, in Mulberry by Peter Coles, we have a splendid account of one of the world’s most celebrated trees, one that shows the events, people, historical twists and turns, and biological peculiarities that moulded today’s species. Given the mulberry’s long association with silk – silkworms will only eat the leaves of the white mulberry – Coles has a huge amount of material to draw on. A less able author might have pitched things too broadly, providing a shallow skim across the history of silk production, or gone to the other extreme, stuffing the book with stats on 18th-century embroidered silk ribbons. Instead, Coles satisfies a number of audiences. For the historically minded, there are the origins of silk cultivation in India and China, and the various attempts – successful and otherwise – to introduce silkworms and their food plant to northern Europe. Those with an economic focus will like the analysis of how European governments tried penalties, persuasion and payouts to get landowners to plant mulberries (importing silk was expensive), while discussions of the members of the genus Morus should please those with a botanical bent. There is plenty of local history too, from the obviously well-travelled Coles. We learn how large parts of central Paris once sported mulberries, about the effect of the Lebanese silk industry on local agriculture, and the rise of the Cheney Bros silk empire in Connecticut. For UK readers, there is an invitation to spot ancient mulberry trees across London and the south-east, the remnants of royal attempts to breed silkworms.
1-8-20 Cuttlefish wearing 3D glasses prove they sense depth just like us
Cuttlefish wearing 3D glasses strike accurately at a virtual shrimp moving on a screen. The finding shows that cuttlefish estimate distances by comparing images from each eye, just like we do. This might seem obvious at first. But, unlike us, cuttlefish lack forward-facing eyes whose fields of vision mostly overlap. Instead, they have outward-facing eyes that give them 360-degree vision, with just 8 degrees of overlap between the eyes. They can move each eye independently, increasing the overlap to 70 degrees when looking at something in front of them. However, it takes a lot of neural processing power to compare the images from two eyes even when the eyes move together like ours, says Trevor Wardill at the University of Minnesota. It should be even harder when the eyes move separately. Other animals with eyes that move independently rely on different mechanisms to work out distance. Chameleons figure it out from how much the lens has to change to focus an image. Many squid rely on a similar trick. They have a bump on their retina that lets them detect how quickly an image goes out of focus. Octopuses, meanwhile, probably can’t sense distance at all. But Wardill suspected cuttlefish use the same method that we do, called stereopsis. To find out, he and his colleague Rachael Feord glued a Velcro strip to the heads of 14 European cuttlefish (Sepia officinalis) so they could quickly and easily attach red-green 3D glasses. Three of the animals always removed the glasses when they were put back in the tank, but 11 tolerated them. Wardill and Feord carried out a series of tests with these cuttlefish, measuring how they positioned themselves and where they tried to grab the virtual shrimp as its apparent position was changed. The findings show that the cuttlefish rely on stereopsis.
1-8-20 Stinky flower is more than a metre wide and the largest ever found
Don’t stop to smell the flowers. Indonesian officials may have found the largest flower ever, and it smells awful. The flower belongs to the Rafflesia genus, whose members are known as corpse lilies or corpse flowers due to their odour of decaying flesh. The stink attracts the insect pollinators these species use to reproduce. This flower appears to be the species Rafflesia tuan-mudae and it measures about 1.1 metres across – about 4 centimetres wider than the previous recorded largest flower, according to CNN Indonesia. It was found in the Maninjau Forest Conservation in West Sumatra’s Agam region. The previous record holder bloomed at the exact same spot, hinting that both may be flowers of the same individual plant. Rafflesia plants are parasitic. They have no leaves, stem or roots, and hide away inside their host plants – in this case a vine – until they are ready to reproduce. At that point a bud forms outside the host plant and slowly blooms over the course of up to a year. The strange-looking bloom fits the flower’s gruesome common name with its thick, mottled red petals. Scientists from the Indonesian forest service will monitor the huge flower’s growth over the next week and watch for the mice and wild boar that sometimes eat corpse lilies. After about a week, the flower will rot and die, leaving the plant invisible inside its host once more.
1-7-20 Australia fires: 'Nothing left' for animals that survive
As bushfires rip across parts of Australia, experts are warning of an immense loss in biodiversity and threat to the lives of millions of animals. One estimate is that in the state of New South Wales alone, nearly half a billion animals have been affected by the fires. John Marsh works at the Potoroo Palace nature sanctuary in the fire-hit Merimbula, New South Wales. He explains how even after the fires pass, surviving animals will face an uncertain future.
1-6-20 Hagfish tie their bodies into complicated knots to escape tight spots
Hagfish literally tie themselves in knots to escape a tricky situation – and that includes tying their bodies into complicated three-twist knots In many ways, hagfish are extraordinary. They are long, eel-like marine animals that carry far more blood relative to their body volume than any other fish, have four hearts – and only half a jaw. It’s partly because of this last feature that it’s so useful for hagfish to tie knots in their long bodies. When the animal ties a knot at its tail end and slips it along the body to the head, it forms a broad flat surface that the hagfish’s upper jaw can work against, creating a makeshift lower jaw. Slipping a thick body knot along its body can also help a hagfish pull its head out of a tight spot if it gets stuck during hunting or feeding. But although we’ve known for decades that hagfish tie themselves in knots, it’s been difficult to confirm what knots they tie. “Three-dimensional knots are difficult to visualise at the best of times,” says Theodore Uyeno at Valdosta State University in Georgia. “But when it’s a squirmy self-manipulating knot that’s thrashing about, it’s impossible.” Uyeno and his colleagues came up with a solution. They anaesthetised a hagfish and gently inserted its head into a restraining device. When the hagfish woke up, it slipped knots down its body to pull its head free: using high-speed cameras, the researchers could record the behaviour and analyse the knots. They repeated the procedure 100 times, capturing the knot-tying behaviour of three hagfish species. Given the length and width of the hagfish body, mathematically they should be capable of tying any one of the eight most primitive knots. But the researchers suspected hagfish would choose not to tie the very simplest knots because the loops in these knots are so tight they might prove painful. “When you tighten a knot, more complex knots are less pinching,” says Uyeno.
1-4-20 Australia fires: How do we know how many animals have died?
There is a widely-reported estimate that almost half a billion (480 million) animals have been killed by the bush fires in Australia. It's a figure that came from Prof Chris Dickman, an expert on Australian biodiversity at the University of Sydney. He released a statement explaining how he had reached the figure - a statement which refers to the number of animals affected rather than those necessarily dying as a direct result of the fire (although the title of the release talks about 480 million being killed). The numbers are based on a report he co-wrote in 2007 for the World Wide Fund for Nature (WWF) on the impact of land-clearing on Australian wildlife in New South Wales. It estimated that there were an average of 17.5 mammals, 20.7 birds and 129.5 reptiles per hectare (10,000 square metres, so a square 100m on each side - about the size of a rugby pitch). They've then multiplied that by the amount of land hit by the fires. "We've estimated that in the three million hectares of New South Wales alone that were burned up until about 10 days ago probably as many as 480 million mammals, birds and reptiles would have been affected by the fires," Prof Dickman said. "Certainly, large animals, like kangaroos or emus - many birds, of course - will be able to move away from the fire as it approaches," he told BBC Breakfast. "I guess it's the less mobile species and the smaller ones that depend on the forest itself that are really in the firing line." But he added that many of those that survived the actual fire would die later because of lack of food or shelter. Colin Beale, an ecologist from University of York told Reality Check that may have been overstated. He said: "In the areas of Africa where I work I am quite sure that very few birds die as a direct result of fire. They certainly have the ability to fly away from fires, and this is surely the case in Australia, too."
1-2-20 Some starfish-like animals see without eyes by changing body colour
Brittlestars, marine animals that look a little like starfish, may see without eyes by changing the colour of their bodies. While we already knew that brittlestars have photoreceptors all along their bodies, we didn’t know exactly how they worked until now. The discovery could help explain how other related marine creatures, like sea urchins, are also able to see without eyes. Lauren Sumner-Rooney at the University of Oxford and her colleagues looked at two closely related species of brittlestars: one that can orient itself towards light, Ophiocoma wendtii, and one that can’t, O. pumila. Both species are highly light averse and spend nearly all their time hidden beneath rocks. Sumner-Rooney wanted to know whether these brittlestars could determine the contrast of a scene, rather than just differentiate between light and dark. This would involve an ability akin to vision. By looking at the two closely related species, Sumner-Rooney and her colleagues were able to surmise that O. wendtii was able to orientate itself towards differing contrasts of light, but O. pumila could not. Sumner-Rooney says this skill comes in handy as “it makes it easier to find somewhere to hide” in complex visual environments like a coral reef. The researchers put individuals from the two species in a 60-centimetre-diameter cylindrical tank. They coloured a narrow band of the tank’s wall black with a white border, and left the rest of the tank’s wall a uniform grey. Because the black and white bands were so close to one another, the light that reflected off them clashed to create a light intensity identical to that from the grey parts of the wall. This means an animal that can simply sense light wouldn’t be able to identify the black band. O. wendtii did tend to recognise the black band and crawl towards it to seek shelter, but O. pumila did not.
1-1-20 Bottlenose dolphins are splitting into two different species
Bottlenose dolphins in South America may be splitting into two different species right before our eyes. Their distinct genetic variations may have come about due to their differing habitats. Along the coastlines of southern Brazil, Uruguay and Argentina in the South Atlantic Ocean, common bottlenose dolphins (Tursiops truncatus) that live near the shore don’t look like their cousins that live further out to sea. They are longer, lighter and have a triangular dorsal fin, in contrast to the offshore dolphins’ hooked dorsal fin and darker skin. The two kinds of common bottlenose dolphin live differently from one another, too. Those in the coastal “ecotype” form small groups in bays and estuaries and don’t stray too far from home, while those in the offshore ecotype live in pods of hundreds and roam widely. When Ana Costa at the University of Glasgow in the UK and her team looked at the dolphins’ skeletons, they found still more differences: the offshore dolphins had shorter and more plentiful vertebrae than the coastal variety. “This is a charismatic, worldwide species, and it is one of the most well-studied cetacean species. Thus it is surprising that, up until now, these differences went undetected,” says Costa. The dolphins were so physically and behaviourally different that Costa wondered if the two groups had gone down different evolutionary paths, separating into two species – meaning that the ecotypes had stopped interbreeding. To find out, she and her colleagues collected more than 250 tissue samples from common bottlenose dolphins of both ecotypes off Brazil’s coast and analysed the DNA. They also compared the skulls of 106 dolphins from the same region. The genetic and skeletal differences were closely grouped together by ecotype, and genetic analysis revealed little evidence of recent interbreeding between the two varieties.