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« Reply #7155 on: Jul 07, 2020, 03:16 AM »

The Truth about Sharks: Why we need sharks: the true nature of the ocean's 'monstrous villains'

Why did dolphins get Flipper while sharks got Jaws? These majestic, diverse animals bring balance to the ocean ecosystem – and they’re in grave danger

    Shark finning: why the ocean’s most barbaric practice continues to boom: https://www.theguardian.com/environment/2020/jul/06/shark-finning-why-the-oceans-most-barbaric-practice-continues-to-boom

by Helen Scales
7 Jul 2020 12.00 BST

Each day, as the sun sets over the coral-fringed Raja Ampat Islands in Indonesia, an underwater predator stirs. As predators go, it’s not especially big or ferocious – an arm’s length from head to tail, with a snuffling, moustachioed snout.

What’s unique is that it doesn’t so much swim along the seabed as walk. Using its four fins as legs, and twisting its spine like a lizard, it can emerge from the water and hold its breath for an hour, strutting across the exposed reef and clambering between tide pools to find prey.

It’s a walking shark, and far from the stereotypical view of these baleful beasts, it tells an alternative story of how sharks look and live. Biologists recently confirmed there are nine species of walking sharks. They are the ocean’s newest sharks – probably only 9m years old as a group, with the two youngest species splitting apart less than 2m years ago – challenging the long-held notion that sharks are ancient and unchanging. They are not evolutionary survivors from bygone eras, but animals that continue to adapt.

The walking sharks themselves are just a fraction of the immense diversity of sharks. There are bramble sharks and gollumsharks, night sharks and shy sharks, clouded angelsharks and splendid lanternsharks; there are fat catsharks, mouse catsharks, frog, cow and weasel sharks. In all, more than 500 elasmobranch species are alive today. One in 10 shark species are bioluminescent: they light up in the dark. Another is so small you could tuck it in a pocket, and it has little pockets of its own – filled, for an unknown reason, with glowing goo. Some sharks puff up to look bigger and scarier than they really are. Mother sharks can be pregnant for three years at a time, or have virgin births.

    There are bramble sharks and gollumsharks, night sharks and shy sharks, clouded angelsharks and splendid lanternsharks

But if all you knew about sharks you learned from Hollywood, you’d think they were aquatic horrors. Sharks have a film genre all their own: there are movies about ghost sharks and zombie sharks, sharks that squirt acid, killer sharks that swim through sand or snow, and a staggering six instalments of the Sharknado film franchise.

Even more problematic is when the more believable films depict sharks as monstrous villains: in 2016, The Shallows featured a female surfer being brutally attacked by a vengeful great white, leading a group of marine scientists to write an open letter to Columbia Pictures warning that the movie was a dangerous mischaracterisation that could keep the tide of public opinion turned against sharks.

0:54..Michael Phelps races a great white shark (sort of) – video: https://www.youtube.com/watch?v=e3VsKheoeBE&feature=emb_logo

In reality, sharks are overfished in their millions. They aren’t adapted to being prey, rather than predator: sharks grow slowly, spending ages as teenagers before reaching maturity; they lay few eggs and give birth to few pups, not enough to replenish dwindling populations. Those that stay alive can spend decades, even centuries, absorbing man-made pollutants and plastics. Individual sharks have seen their world become hotter and more acidic in their lifetime: Greenland sharks swimming around today were born when the Arctic Ocean was several degrees cooler. The upshot of all this is bleakly predictable. At last count, a quarter of all sharks and their flattened cousins, the rays, were found to be threatened with extinction.

Sharks matter to humanity. Much is lost when they vanish from the seas. “There’s a lot we can learn from sharks,” says Jasmin Graham, shark biologist and project coordinator of MarSci-Lace at Mote Marine Laboratory in Florida, where researchers are investigating how sharks quickly heal wounds and how they evolved immunity to many diseases. “If they’re not here, then that evolutionary history, that information, is lost.” At the 2008 Beijing Olympics, swimmer Michael Phelps won eight gold medals wearing a suit inspired by the tiny, toothlike denticles in sharks’ skin that reduce drag and boost their speed. (The suits were later banned after studies revealed that they trap air bubbles, helping swimmers float.)
Whale shark (Rhincodon typus) in La Paz bay, Baja California Sur, Mexico.

Sharks matter not just because they can be useful for humans, however, but entire ocean ecosystems. “Lots of shark species have been shown to be keystone predators,” says Graham. “They maintain balance in ecosystems and keep things in order, removing weaker, sicker prey and stopping any single species from exploding in numbers and taking over.” One study comparing remote islands in the Central Pacific showed that when sharks are fished out, coral reefs can become dominated by small fish and overrun by algae. “We don’t understand until we lose the species how important it was,” says Graham.

    Sharks maintain balance in ecosystems and keep things in order
    Jasmin Graham, shark biologist

We need to talk about sharks. Though no sharks have yet gone the way of the dodo, plenty of species are lined up for imminent extinction. And the loss of sharks is not just about species blinking out, but a diminishment from their former abundance. Just like the erasing of native fauna from the continents – of bears and wolves, tigers and lions, koalas and kakapos – so the oceans are now losing their sharks. The only difference is that their dying out mostly goes unnoticed.

In more than 20 years of diving and researching the oceans I’ve had many encounters with wild sharks, each one a moment to treasure and note in my dive logbook. I used to feel adventurous when family and friends asked me if I was scared to dive with sharks. (No, never.) But increasingly, as the question keeps being asked, it unsettles me – that so many people still think this way.

For years, scientists and conservationists have been saying that sharks have more to fear from humans than we have from them. Pick whichever statistic you like best of things far more likely to kill you: a toppling vending machine, a falling coconut. Still there’s this lingering idea that sharks are dangerous, vindictive and brutal. Fear is certainly not being deliberately stoked by the very few people who’ve been attacked by sharks, many of whom, despite losing limbs, have become outspoken advocates for shark conservation.

“As a kid, I saw Jaws, and I wasn’t particularly scared of it,” says Graham. “I was just asking why? Why do people think that they’re so scary? How are they different from a dolphin? They’re both predators. Why did the sharks get a bad rep and dolphins got to have Flipper?”

These majestic animals are doing much worse worldwide than they were back in 1975 when Jaws was released. They need all the positive publicity they can get. New stories need to be told about sharks – the big ones and small ones, the ones that walk and glow, and all the other things they can be.

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« Reply #7156 on: Jul 07, 2020, 03:18 AM »

Russia cracks down on marmot hunting after suspected bubonic plague cases

Possible outbreaks in China and Mongolia have brought bans on hunting and eating the rodents, which can carry the disease

Tue 7 Jul 2020 01.36 BST

Russia has stepped up patrols to stop people hunting marmots near its border with China and Mongolia after the countries reported possible cases of bubonic plague, which can be carried by the animals.

Authorities in Bayan Nur, a city in the Chinese region of Inner Mongolia, issued a warning on Sunday after a hospital reported a suspected case of the deadly disease.

The Chinese region forbade the hunting and eating of the large rodents and asked the public to report any suspected cases, as well as any sick or dead marmots.

Neighbouring Mongolia also reported two cases of bubonic plague linked to people eating marmot meat in its western Khovd province last week.

Authorities in Russia’s Altai region, which borders Kazakhstan, China and Mongolia, said officials were patrolling the area to enforce a ban on hunting marmots and to warn people about the dangers, TASS news agency reported.

The local branch of Rospotrebnadzor, the consumer health watchdog, said the cases across the border did not pose a threat to people in Altai, TASS reported.

The bubonic plague, known as the Black Death in the Middle Ages, is a highly infectious and often fatal disease that is spread mostly by rodents. however it can be treated with commonly available antibiotics. Bubonic plague outbreaks have become increasingly rare.

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« Reply #7157 on: Jul 07, 2020, 03:21 AM »

Wolf puppies play fetch, too, scientists find

By Agence France-Presse

It’s a game familiar to most people: you throw an object a short distance, and wait as your joyful canine companion leaps to intercept and return the missile, encouraged by words of praise or a pat on the head.

Such scenes have no doubt played out over millenia, symbolizing the unshakeable bond of friendship between humanity and our “best friends” ever since dogs were domesticated from wolves at least 15,000 years ago.

But a new study in the journal iScience shows that some wolf puppies also know how to play fetch, upending the long-held hypothesis that the ability to interpret subtle human social cues is unique to dogs and arose as a result of selective breeding.

The finding was made by chance as researchers in Sweden subjected 13 wolf puppies born to three different litters to a series of behavioral tests.

The team was raising wolf and dog puppies from the age of 10 days old in order to answer fundamental questions about how the two species differ, and what they have in common.

It wasn’t until the third year of the program that lead author Christina Hansen Wheat, a behavioral ecologist at the University of Stockholm noticed that some eight-week-old wolf pups actually paid attention to a stranger throwing a ball and asking them to return it — despite no prior training.

“When I saw the first wolf pup fetch the ball, I got goosebumps — whoa, that’s unexpected,” she told AFP. “Then I had two more doing the same thing, and so that was pretty exciting.”

The pups were subjected to consecutive trials, with a total of three of the 13 showing the ability to play the game consistently.

This suggests that, while rare, variation among wolves in so-called “human directed behavior” was a key factor in which ones were selected by prehistoric people for further breeding.

Hansen Wheat believes the finding adds an intriguing “new piece to the puzzle” of the question of dog domestication — a deeply contested area of study, with scientists in disagreement over the timeline, geographic locations and conditions that led to one of the most fruitful partnerships in human history.

© 2020 AFP

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« Reply #7158 on: Jul 07, 2020, 03:25 AM »

Seabirds are using tools now

By Mike Wehner

One of the things that have differentiated humans and primates from other groups in the animal kingdom is the use of tools. There are other species that have been observed using tools, but not many, and discovering that a species has mastered the art of using some type of implement is always exciting.

Now, researchers from the University of Oxford and the South Iceland Nature Resource Centre claim they have concrete evidence that seabirds — specifically puffins — are indeed tool users. The work was published in Proceedings of the National Academy of Sciences.

Some species of birds have been known to use tools for various purposes. Crows, in particular, have shown an ability to grasp the use of tools to accomplish a task. This new study is the first to show that the same is true for seabirds.

In studying the puffins on Grimsey Island, the researchers spotted puffins using sticks for a very specific purpose: scratching themselves. As the researchers explain, the puffins on the island often deal with parasites on the outsides of their bodies, possibly causing them discomfort. At least some of the birds appear to have come up with a solution to this unfortunate problem, and they’ve been observed using sticks to scratch hard-to-reach parts of their bodies.

It’s an interesting discovery, especially since seabirds like puffins tend to have smaller, less complex brains than those of other tool-using birds, like crows. The researchers observed puffins using sticks in this manner in two separate locations, suggesting that it wasn’t an isolated development or random chance. Puffins, it seems, are comfortable with tools.

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« Reply #7159 on: Jul 07, 2020, 03:28 AM »

Dover clifftops 'buzzing with wildlife' after National Trust takeover

Restoration work and wet winter have led to an explosion of colour and an increase in birds

Steven Morris

A well known piece of the British landscape that had become depleted of flora and fauna because of years of intensive farming is alive with wildflowers, butterflies and birds this summer.

Since the National Trust acquired fields on top of the white cliffs of Dover two and half years ago after a £1m national appeal championed by Dame Vera Lynn, it has worked to restore the area to rich grassland.

The charity is excited at the results, reporting an increase in birds including skylarks, corn buntings, partridges and meadow pipits. Peregrine falcons are benefiting from an increase in wild pigeons, a main source of prey.

Fields have been vivid with poppies, ox-eye daisies and buttercups, and staff hope the new habitat will in time support chalkland butterfly species such as the adonis blue and the dingy skipper, as well as continuing to provide a home for more common marbled whites and red admirals.

The fields are part of a 178-acre plot that the trust bought in 2017. It immediately set about reversing the effect of 70 years of intensive agriculture that began after the second world war.

In 2018, barley was sown to remove some of the nutrients from the well-fertilised soil, preparing it for a wildflower and grass mix. Typically, chalk grassland wildflowers prefer a low-nutrient soil to thrive.

A “bumblebird” seed mix, which includes cereals, brassicas and wildflowers, was sown last autumn to provide birds with a supply of food through the winter, and a range of nectar-rich plants for pollinators in the summer. The wet winter that followed helped create an explosion of colour.

Virginia Portman, the general manager at the white cliffs for the trust, said: “After many decades of intensive farming, it’s fantastic to see this stretch of the cliffs buzzing with wildlife again.

“The cliffs hold an incredibly special place in our country’s history, but they’re also important for nature as much of the habitat we have here, chalk grassland, is increasingly rare in the UK.

“To see the fields returning to their natural state, covered in poppies and ringing with the sound of skylarks, is really heartening. It’s a tribute to everyone who supported our campaign and helped us buy back this landscape for the nation.”

The trust’s 2017 fundraising campaign reached its target in just three weeks, its success credited in part to the support of Lynn, who died aged 103 last month.

Portman said: “The white cliffs of Dover will be forever intertwined with Dame Vera Lynn. Her music marked the start of the enduring emotional connection that people feel when they visit us here, and we’re so grateful for her support over the years. In helping us to save the land and restore it as a haven for wildlife, she has left a legacy for future generations to enjoy.”

Mark Love, who carries out surveys for the British Trust for Ornithology (BTO) in the area, said: “The quantity of skylarks, meadow pipits and corn buntings clearly enhanced by the changed land management is remarkable.”

Saturday is National Meadows Day in the UK. According to the charity Plantlife, 7.5m acres of meadows and flower-rich grasslands have been lost since the 1930s.

In the longer term, the trust aims to join up 150 hectares of habitat along the cliffs, linking land purchased in 2012 and 2017.

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« Reply #7160 on: Jul 08, 2020, 03:19 AM »

Great white vanishing act: where have South Africa's famous sharks gone?

Longline fishing, pollution, the arrival of orcas – what’s causing these crowd-drawing sharks to shun Cape Town’s waters?

Jason Burke Africa correspondent
Wed 8 Jul 2020 07.00 BST

For those who watch the waves, rocks and beaches for the distinctive silhouettes and dorsal fins, there is still hope. If the great white sharks are gone for now, they will return, one day soon.

Not so long ago, there were 200 or more annual sightings in South Africa’s False Bay of the most famous of sharks. The sheer numbers gathering around one island off the stunning curve of sand just east of the Cape of Good Hope and the city of Cape Town made it the “great white capital of the world”.

This year, a single shark has been seen. Last year, not one.

“We need to keep watching to work out what has changed and why, and when they may come back. For now, we are still really hopeful the sharks will return,” says Sarah Waries, of Shark Spotters, an organisation largely funded by local authorities to monitor the population of great whites in False Bay and watch over the beaches.

For Gregg Oelofse, the absence of the great whites could be the most dramatic environmental change he had seen in 20 years as a conservation biologist in the area.

“It would be a massive loss for Cape Town. They are such a big part of the environment, of our sense of place and identity here, it would be a tragedy if they never came back,” says Oelofse, head of coastal management for Cape Town.

The great whites are important for economic as well as environmental reasons. They are part of a £2bn-a-year tourist industry, as much of an attraction as Cape’s vineyards, game reserves, fine dining or Table Mountain.

The tour companies taking visitors out in boats to view the sharks, or lowering them in cages into the sea for closer encounters, employ hundreds in a country that suffers from an acute lack of jobs.

Though there are still other sharks to view, the absence of the crowd-drawing great white is a challenge to an industry seen by some as a leading example of successful eco-tourism.

Experts began to notice the decline of the great whites about five years ago, and remain divided over the reason for their absence from False Bay. Some have suggested the arrival in 2015 of orcas, another apex predator that attacks sharks, forced even the great whites to retreat.

Two orcas, named Port and Starboard, have been seen repeatedly in False Bay, most recently last month. Carcasses of large great whites have been found with evidence that the orcas killed them for their livers.

Oelofse says that the orcas’ arrival could be a factor but not the only reason for the great whites’ absence. Instead, research suggests the population of great whites has been in freefall for many years.

Dr Sara Andreotti, a marine biologist at Stellenbosch University who has been studying South Africa’s great whites for more than a decade, estimated in 2012 there were no more than 522 off South Africa’s coastline.

Andreotti’s research also showed that South Africa’s great whites were not sufficiently genetically diverse to cope easily with new threats.

These ranged from possible pollution – such as heavy metals entering the food chain and possibly damaging sharks’ reproductive systems – to the impact of longline fishing boats that have taken huge numbers of fish from the waters east of False Bay in recent years.

Great white sharks have been protected since 1991 in South Africa, but other shark species that provide much of their diet are not.

Andreotti says: “You cannot protect the predator without protecting its food. Sharks are not sardines. They are very slow to reproduce. You can fish but you have to do it in a sustainable way. That will be less profitable in the short term but will not crash the entire environment and the industry.”

2:49..Shark spotting: how a drone app is helping to keep Sydney's surfers safe in the water – video: https://www.youtube.com/watch?v=zFu-c62O3mg&feature=emb_logo

Chris Fallows, a respected shark expert and guide based close to Cape Town, is in no doubt that longline fishing was responsible for the disappearance of the great whites.

He says the populations of two species that provide much of the food of the great whites had collapsed.

“If you stopped the demersal shark longlining then there is every chance they will come back, but not in a hurry. The marine ecosystem has been intact for millions of years and in the space of five we have laid it to waste,” he says.

Local officials have shown limited interest in the problem, though the South African department of environment, forestry and fisheries has appointed an expert panel to recommend actions needed “to properly manage and conserve all shark species found along the country’s coasts, and to guide their long-term sustainable use”.

Waries remains optimistic. She remembers how numbers of sightings dropped markedly between 2008 and 2009, before a surge in 2010 when the great whites returned almost overnight.

“It’s still early days … We keep hoping they come back soon, but soon doesn’t seem soon enough. We must just be patient,” Waries says.

Oelofse described anecdotal evidence of long periods in the past century when there may have been fewer sharks in False Bay, and says that there had “peaks and troughs” in recent decades.

“It is possible that there are bigger cycles here [over longer timespans] that we just don’t know about yet … The level of our knowledge really isn’t that strong,” he says.

“I’m hopeful the sharks will return but the longer they are gone the lower the chances seem of that happening.”

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« Reply #7161 on: Jul 08, 2020, 03:21 AM »

Bright feathers, bright brains: hummingbirds 'can order numerically'

Study claims tiny creatures can order things in sequence, but researchers say it does not confirm they can count

Nicola Davis

Hummingbirds are not only bright in appearance but also in brain, it would seem, with new research suggesting the tiny creatures are able to understand a numerical concept of order.

While hummingbirds have previously been found to visit flowers in particular sequences when foraging, researchers say the new study suggests this process could be based on the concept of “first”, “second” and so on, rather than features such as specific flower location or nearby landmarks.

However, it does not mean that hummingbirds can count.

“Counting has a more anthropocentric connotation,” said Dr Maria Tello-Ramos of the University of St Andrews, a co-author of the study. “This is more like ordering things in a sequence. We cannot say [the hummingbirds] were counting, ‘One, two, three, four,’ but that they knew that [the] fourth [flower] was different from the third flower that they encountered,” she said.

Tello-Ramos added that such a skill could help hummingbirds attach information to their foraging sequence, such as that the second flower has run out of nectar, meaning they know to skip it – even if it looks unchanged – and move on to the next in the sequence.

Some other animals that have undergone training, including rats, monkeys, bees and parrots, have previously been found able to grasp that items in a sequence can take a particular order based on an abstract numerical concept.

However, the team behind the new research said their study was the first time such a capability had been shown in a wild, free-living vertebrate.

Writing in the Proceedings of the Royal Society B, Tello-Ramos and colleagues reported how they made their discovery by presenting nine male rufous hummingbirds with a row of 10 identical fake flowers on sticks spaced 20cm apart, with each flower constructed from a foam disk with a tube in the centre.

To train the hummingbirds, the team filled the inner tube of the first fake flower in the row with a sugary solution. Once each hummingbird visited this flower four times in succession, the flowers were shuffled – to take account of any subtle differences between them – and the first flower in this new row was filled with a sugary solution.

The training was repeated with the sweet treat in the second, third and finally the fourth flower. The team found all the hummingbirds learned to fly to correct flower, with the one containing the sugar visited significantly more than would be expected by chance during the training.

To check that the birds were not simply learning which flower to pick by its distance along the row, the team presented the birds with a row of randomly spaced fake flowers. The results show that the birds had a clear preference for flying straight to the flower containing the sugary solution.

Tello-Ramos said the findings added a numerical concept of order to a growing list of information that hummingbirds use to get by, including location and flower colour. “If the information is relevant, the humming bird will use it,” she said

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« Reply #7162 on: Jul 08, 2020, 03:24 AM »

The Cuttlefish, a Master of Camouflage, Reveals a New Trick

By Veronique Greenwood
NY Times

Consider the cocktail umbrella. Like their larger counterparts, these wee things can be furled and unfurled easily. Once you tire of playing with them, you can lock them into the open position with a little latch before continuing to enjoy your drink.

Now imagine you have hundreds of cocktail umbrellas under your skin. This, it turns out, is fairly close to reality for cuttlefish, the sprightly relatives of squids and octopuses, according to new research.

Biologists at the University of Cambridge and the Marine Biological Laboratory in Woods Hole, Mass., have discovered that cuttlefish, masters of camouflage whose shape-shifting talents have fascinated biologists for decades, can lock hundreds of tiny structures under their skin into an upright position, giving themselves a particular texture, then go on their way without expending any energy to keep up the look.

This is the first time anyone has seen anything like this in cuttlefish, a reminder that even much-studied species still have some surprising secrets.

Cuttlefish are the chameleons of the sea: Put one in front of a bank of seaweed and he or she will immediately activate a set of reflectors and colored cells in the skin to match their background and fade from view.

What’s more, they will mimic the texture of their environment using little nodules called papillae that they extend and retract using muscles. They can make themselves look like a cobbled seafloor, a spiny piece of coral or a hunk of granite.

“They’re even clever enough that they’ll put the posture of their arms to match things in their environment,” said Trevor Wardill, a neurobiologist at the University of Cambridge and contributor to the study, published Thursday in iScience. “If there’s seaweed on a 45-degree angle, they’ll set their arms to match.”

In the current study, as part of an experiment to help understand how cuttlefish control their color and shape, Dr. Wardill’s colleague Paloma Gonzalez-Bellido snipped a nerve that controls one section of the cuttlefish’s skin.

One of the two cuttlefish she used in the experiment, as expected, kept its skin smooth and could no longer change color in the portion affected by the surgery, though it swam around healthily enough.

The other, however, had had its papillae extended at the moment the cut was made. To Dr. Gonzalez-Bellido’s surprise, they did not relax. Instead, as she perplexedly moved the animal to different water tanks and watched its unaffected side change shape and color quite normally, the papillae stayed up. Only after an hour did they finally subside.

It turns out that these papillae can be locked in position if they are dosed with certain neurotransmitters, which that particular cuttlefish had likely just released when the nerve was cut.

The researchers believe that cuttlefish use this previously unknown locking mechanism to sustain their disguise as a piece of rock or coral without having to actually hold their muscles in the same posture for an extended period of time.

This is similar to a well-known phenomenon in clams and related creatures: When these mollusks want to clam up, they lock the muscles that open and close their shells by altering the chemistry of certain muscle proteins. In both cases, it seems that this approach can save energy for the animal, as it doesn’t have to strain to maintain its pose.

Ultimately the study may offer a path toward understanding other mysteries about cuttlefish. If the researchers can decipher the individual neurons that control each of these papillae and understand better how this lock functions, it may lead to deeper insights into how these strange and beautiful creatures hide themselves in plain sight.

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« Reply #7163 on: Jul 08, 2020, 03:26 AM »

Country diary: the dipper's sweet singing lifts the winter gloom

Allendale, Northumberland: The song’s fluidity mimics the movement of the river where it lives and is especially cheering on a cold morning


There’s very little birdsong in this valley right now. Just thin wisps of notes from the robin, the see-sawing sounds of great tits on warm days or wild bursts from mistle thrushes that, in some years, I’ve recorded in my diary around Christmas time.

There’s one bird, though, that sings throughout the year and that is the dipper. I listen for it when I step outside the back door. This song has a fluidity that seems all about the movement of the river where it lives, a stream of calmer moments followed by flurries of repeated notes. It has some of the sweetness of the skylark mixed with the variety of the thrush. In summer, I straighten from working the veg garden to take notice. In winter, when even the sheep are silent, it’s especially uplifting.

On this cold January morning I go out into the glinting world of the frosted field. There’s ice on the pussy willows, ice on tufts of caught wool, ice turning barbed wire into tinsel. Where the river bends, a dipper sings from a boulder in the fast-flowing mid-current; favourite perching rocks are streaked in white droppings at intervals down the stream. They have a strong attachment to territory, with nest sites being traditional, and pairs are monogamous, sometimes for years.

As a child, I first saw a dipper walking underwater below Jedburgh Abbey. Through the clarity of the Jed, I marvelled as it picked food from the gravel bed; mayfly nymphs, caddisfly larvae and tiny fish such as minnows are in its diet.

Dippers have dense feathers, preened with oil to waterproof them, and they manoeuvre through the water using their wings. They are unfazed by cold. In the winter of 2010, when the East Allen had all but frozen over, water gurgling beneath a solid five inches as if in a cavern, I watched a dipper feeding. A dark blur, it moved resolutely this way and that, popping up occasionally, flicking its nictitating membranes over its eyes.

Mating early in the season and being equipped for tough weather, the dippers of the East Allen may have their first clutch within only seven or eight weeks.

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« Reply #7164 on: Jul 09, 2020, 03:23 AM »

The ocean’s largest mystery – why has no one seen a whale shark give birth?

A world-first ultrasound and chance sightings of potential mating rituals could help in the urgent work to save these gentle giants from extinction

Ashifa Kassam
Thu 9 Jul 2020 06.59 BST

Covered in polka dots and stretching the length of a single-decker bus, the gentle giant barrelled towards them. The team of scientists, ready with a 17kg waterproof ultrasound machine they had lugged to one of the world’s most isolated dives sites, waited for the whale shark.

Months of preparation had gone into the encounter, expected to last between 30 and 45 seconds. Aided into position by a propeller mounted on his air tank, one scientist glided underneath the hulking animal as it swam by, raking a handheld probe across her distended belly – yielding the world’s first ultrasound of a wild whale shark.

The ultrasounds, carried out in 2018 on three females off the Galápagos Islands, were aimed at teasing apart one of the ocean’s greatest mysteries: decades after research began in earnest on whale sharks, scientists have few clues as to how they mate or where they give birth.

1:25..Divers in Thailand attempt to free whale shark entangled in rope – video: https://www.youtube.com/watch?v=th1-KdTgSdM&feature=emb_logo

“Here is the biggest fish in the oceans, it’s almost certainly the biggest shark,” says Jonathan R Green, the director of the Galapagos Whale Shark Project. “And what is known about their reproductive behaviour is almost nothing.”

For more than 70m years, some form of the whale shark has roamed the oceans, their existence overlapping with the Tyrannosaurus rex at one point. A docile filter-feeder, the whale shark challenges the stereotype of sharks as giant, toothy predators. Its 300 of rows of teeth are microscopic, it moves through the water at a relatively plodding pace and has been known to allow phalanxes of other fish to hitch a ride.

Still, whale sharks have proven to be just as headline-grabbing as their fearsome relatives. Researchers in Japan recently discovered that they have retractable eyes, with the eye surface around the iris covered in nearly 3,000 tiny tooth-like structures known as “dermal denticles”, while another research team documented thousands of shrimp-like creatures living in the mouth of one whale shark.

“There are few things today on our planet that you can say, ‘that is absolutely new to science, we didn’t know that before’,” says Green. “So it’s a bit like the discovery of gravity – it’s an exciting field to work in, but it can be frustrating too.”

Green and his team carried out the ultrasounds after noticing that the whale sharks that gather off the Galápagos were nearly all females with swollen bellies, in contrast to the large gatherings of mostly juvenile males in coastal regions around the world.

While the ultrasounds didn’t confirm the whale sharks were pregnant, they did reveal ovaries and what appeared to be unfertilised eggs, hinting that more research is needed to untangle the significance of the area to whale shark reproduction.

Green and his team also tagged several of the animals, only to find out that they often dive beyond the 2,000-metre range of the tags. He and his team have been at pains to explain this “spiralling behaviour”, as the deep water dives seemingly confer little advantage in escaping predators, birthing pups or finding the plankton that whale sharks mostly feed on.

“So it’s layer upon layer of mystery that we’re trying to peel our way through,” says Green. “And every time we come up with some kind of significant data, it just begs a whole series of new questions.”

These questions have taken on new urgency in recent years. “Every day there are fewer of them,” says Green. “We’re losing these animals at a rate which is unprecedented in the history of planet Earth, perhaps with the exception of the Cretaceous-Tertiary K-T mass extinction, when the dinosaurs were wiped out.”

Whale sharks were listed as endangered in 2016, their survival imperilled by fisheries, where they turn up as by-catch, and the demand for shark fins in Asia – with a single pectoral fin able to net as much as $20,000 (£16,000).

The search for answers, however, has in part been stymied by the technical challenges of tracking an animal that ranks among the ocean’s most widely travelled, shifting between open ocean, coastal areas and the deep sea. A 2018 study on a whale shark named Anne saw her travel more than 12,500 miles across the Pacific over the span of two years and three months, at one point making her way to the Mariana Trench – the deepest place on Earth.

The glaring gaps in our knowledge about the world’s biggest fish, however, also reflect our priorities as a society, says Green. “We’ve literally shown more interest in exploring outer space than we have the depths of our oceans.”

    We’ve shown more interest in exploring outer space than we have the depths of our oceans
    Jonathan R Green, Galapagos Whale Shark Project

Scientists are now locked in a race against time. “How can you have an informed conservation plan for an animal if you don’t know how, when or where it breeds?” asked Alistair Dove, the vice-president of research and conservation at the Georgia Aquarium in Atlanta, US. The aquarium is home to four juvenile whale sharks that have yet to reach sexual maturity.

In the wild, once whale sharks are born, little is known about the first years of their lives, he says. “There’s a sort of lost years period, between when they’re born at about 45–60cm long, until they’re up to about 3–4 metres long. That period in between there, we don’t know where they are.”

Tantalising clues have turned up around the world. A pregnant female harpooned by a commercial fishing vessel in Taiwan in 1995 was found to be carrying more than 300 pups in different stages of development. Analyses carried out years later allowed researchers to determine that 29 pups still remaining from the litter all had the same father, suggesting whale sharks mate once, store the sperm and fertilise their own eggs as needed, says Jennifer Schmidt, the director of science and research for the Shark Research Institute.

A 2019 video, shot by a pilot flying over the Ningaloo reef in Western Australia, showed an adult male whale shark swimming erratically, zigzagging through the water as it seemingly vied for the attention of a nearby female. Then it flipped upside down, underneath the female, brandishing his two claspers – the name given to the male’s penis-like organs. While some celebrated the video as a mating act caught on camera, it’s clear that the female was too young to breed, says Schmidt.

“You’ve got a juvenile with an adult – it could be some sort of mating play behaviour, some sort of practice, but it’s not a bona fide mating event because one of the sharks is not old enough to be reproductive,” she added.

Over the years, two eyewitness reports of mating have been documented, both of them from the far-flung island of St Helena in the south Atlantic. Unaware of each other’s reports, two men described the same ritual: splashing that gave way to the male and female in vertical positions – belly to belly – before the female ended up on top and the male slipped underneath her.

    It’s frustrating that we can have this enormous animal and know so little about it
    Alistair Dove, Georgia Aquarium

The reports were bolstered by the fact that the waters off the volcanic island are one of the few places in the world where adult male and female whale sharks have been spotted in equal numbers.

“I have no doubt they both saw whale shark mating,” says Dove of the Georgia Aquarium, who travelled to St Helena after hearing of the reports. “We just don’t have that thing that everybody expects in the 21st century, which is if you didn’t get it on video, it didn’t happen.”

In the absence of hard evidence, he and other scientists are pushing forward, determined to uncover the secrets that have surrounded whale sharks for millions of years. “The ocean holds on to her secrets pretty tightly,” says Dove.

“It’s frustrating to me, as a marine biologist, that we can have this enormous animal and know so little about it,” he adds. “The whale shark is now endangered. And we can’t expect to pull it back from that situation if we don’t understand how that life history works.”

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« Reply #7165 on: Jul 09, 2020, 03:30 AM »

Birdwatching increased tenfold last lockdown. Don't stop, it's a huge help for bushfire recovery

Australians are reporting bird sightings at record rates – it’s good for the spirit, and for science

Ayesha Tulloch, April Reside, Georgia Garrard, Michelle Ward and Monica Awasthy for the Conversation
Thu 9 Jul 2020 07.06 BST

Many Victorians returning to stage-three lockdown will be looking for ways to pass the hours at home. And some will be turning to birdwatching.

When Australians first went into lockdown in March, the combination of border closures, lockdowns and the closure of burnt areas from last summer’s bushfires meant those who would have travelled far and wide to watch their favourite birds, instead stayed home.

Yet Australians are reporting bird sightings at record rates – they’ve just changed where and how they do it.

In fact, Australian citizen scientists submitted 10 times the number of backyard bird surveys to BirdLife Australia’s Birdata app in April compared with the same time last year, according to BirdLife Australia’s Dr Holly Parsons.

But it’s not just a joyful hobby. Australia’s growing fascination with birds is vital for conservation after last summer’s devastating bushfires reduced many habitats to ash.

Birds threatened with extinction

Australia’s native plants and animals are on the slow path to recovery. In our research that’s soon to be published, we found the fires razed forests, grasslands and woodlands considered habitat for 832 species of native vertebrate fauna. Of these, 45% are birds.

Some birds with the largest areas of burnt habitat are threatened with extinction, such as the southern rufous scrub-bird and the Kangaroo Island glossy black cockatoo.

Government agencies and conservation NGOs are rolling out critical recovery actions.

But citizen scientists play an important role in recovery too, in the form of monitoring. This provides important data to inform biodiversity disaster research and management.

Record rates of birdwatching

Birdwatchers have recorded numerous iconic birds affected by the fires while observing Covid-19 restrictions. They’ve been recorded in urban parks and city edges, as well as in gardens and on farms.

In April 2020, survey numbers in BirdLife Australia’s Birds in Backyards program jumped to 2,242 – a tenfold increase from 241 in April 2019.

Change in the number of area-based surveys by Australian citizen scientists over the first six months of 2019 compared with 2020. Data sourced from BirdLife Australia’s Birdata database.

Similarly, reporting of iconic birds impacted by the recent bushfires has increased.

Between January and June, photos and records of gang-gang cockatoos in the global amateur citizen science app iNaturalist increased by 60% from 2019 to 2020. And the number of different people submitting these records doubled from 26 in 2019 to 53 in 2020.

What’s more, reporting of gang-gangs almost doubled in birding-focused apps, such as Birdlife Australia’s Birdata, which recently added a bushfire assessment tool .

The huge rise in birdwatching at home has even given rise to new hashtags you can follow, such as #BirdingatHome on Twitter, and #CuppaWithTheBirds on Instagram.

A gang-gang effort: why we’re desperate for citizen scientists

The increased reporting rates of fire-affected birds is good news, as it means many birds are surviving despite losing their home. But they’re not out of the woods yet.

Their presence in marginal habitats within and at the edge of urban and severely burnt areas puts them more at risk. This includes threats from domestic cat and dog predation, starvation due to inadequate food supply, and stress-induced nest failure.

That’s why consolidating positive behaviour change, such as the rise in public engagement with birdwatching and reporting, is so important.

Citizen science programs help increase environmental awareness and concern. They also improve the data used to inform conservation management decisions and inform biodiversity disaster management.

For example, improved knowledge about where birds go after fire destroys their preferred habitat will help conservation groups and state governments prioritise locations for recovery efforts. Such efforts include control of invasive predators, supplementary feeding and installation of nest boxes.

Better understanding of how bushfire-affected birds use urban and peri-urban habitats will help governments with long-term planning that identifies and protects critical refuges from being cleared or degraded.

And new data on where birds retreat to after fires is invaluable for helping us understand and plan for future bushfire emergencies.

So what can you do to help?

If you have submitted a bird sighting or survey during lockdown, keep at it! If you have never done a bird survey before, but you see one of the priority birds earmarked for special recovery efforts, please report them.

There are several tools available to the public for reporting and learning about birds.

A female superb lyrebird calls to her reflection in a parked car in suburbia. Her nest was later discovered 100 meters from the carpark: Watch: https://vimeo.com/418684600

iNaturalist asks you to share a photo or video or sound recording, and a community of experts identifies it for you.

BirdLife’s Birds in Backyards program includes a “bird finder” tool to help novice birders identify that bird sitting on the back verandah. Once you’ve figured out what you’re seeing, you can log your bird sightings to help out research and management.

For more advanced birders who can identify birds without guidance, options include eBird and BirdLife’s Birdata app. This will help direct conservation groups to places where help is most needed.

Finally, if there are fire-affected birds, such as lyrebirds and gang-gang cockatoos, in your area, it’s especially important to keep domestic dogs and cats indoors, and encourage neighbours to do the same. Report fox sightings to your local council.

If you come across a bird that’s injured or in distress, it’s best to contact a wildlife rescue organisation, such as Wildcare Australia (south-east Queensland), Wires (NSW) or Wildlife Victoria.

By ensuring their homes are safe and by building a better bank of knowledge about where they seek refuge in times of need, we can all help Australia’s unique wildlife.

• Ayesha Tulloch is a DECRA research fellow at the University of Sydney; April Reside is a researcher at the Centre for Biodiversity and Conservation Science at the University of Queensland; Georgia Garrard is a senior research fellow for the Interdisciplinary Conservation Science Research Group at RMIT University; Michelle Ward is a PhD Candidate at the University of Queensland; and Monica Awasthy is a visiting research scientist at the Environmental Futures Research Institute at Griffith University.

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« Reply #7166 on: Jul 09, 2020, 03:33 AM »

Entire rare bird colony vanishes, baffling New Zealand scientists

Experts believe endangered shore plovers – known for their pluck and friendliness – might have flown away or been eaten by predators

Eleanor Ainge Roy in Queenstown
Thu 9 Jul 2020 00.37 BST

A specialist search and recovery team has been deployed to recapture the last remaining survivors of a flock of endangered birds that absconded from a predator-free island in New Zealand during coronavirus lockdown.

There are only 250 shore plover or tūturuatu left in the wild and they are the world’s rarest plover. Conservationists have been painstakingly reintroducing them to the mainland after they were almost wiped out by cats and rats by 1880.

The birds survived for another 100 years in a remote colony on the Chatham Islands, 650km west of New Zealand.

Shore plovers are endemic to New Zealand and renowned for their “attitude and friendliness” – traits which alongside their ground nests make them highly vulnerable to predators.

Mana Island off the coast of the North Island’s Kapiti coast was a successful home to an introduced colony of plovers in 2007. But a few short years after being introduced a single rat wiped out half the population, with the rest dying shortly later due to “complications”.

After the 2007 devastation conservationists avoided reintroducing the plover until the pest situation was resolved.

But in April and May they again took the plunge, transporting 29 young birds to the island, some of whom required ministerial approval to travel during the Covid-19 lockdown.

The birds were colour-banded but not tracked, the department of conservation (DoC) said, and it now appears nearly the entire population has again vanished: either having being killed by avian predators such as rūrū, or having flown off to the mainland.

Shore plover recovery group leader Dave Houston from DoC said the birds’ mysterious disappearance was “frustrating”, as substantial time and money had gone into their recovery.

Houston said his team were unsure what exactly had happened to 26 of the birds, though it had tracked three survivors to Plimmerton beach on the mainland, with a search and recovery team hoping to recapture them later this week. Reports from the public have been helping DoC keep tabs on the survivors.

“The birds haven’t stayed at home like we hoped they would,” Houston said.

“We honestly don’t know what is making them leave; but it could be that a single bird decided to fly to the mainland and everyone else followed them – it could be random behaviour, we’re not sure.”

    We can give them strict instructions, but they choose not to obey
    Dave Houston

In past releases shore plovers had been found to fly as far south as Christchurch in the South Island, and despite their small size they showed considerable pluck, Houston said.

“It is frustrating, we can give them strict instructions, but they choose not to obey. They are a challenging species to manage, so it’s a great loss to then lose them. But we persist.”

If the three survivors are captured they will be returned to Mana Island and held in an aviary for a month rather the usual week to help them establish “fidelity” to the island, Houston said.

Radio transmitters would also be attached to the birds so conservationists “can determine their fate … We might not find them at all though,” Houston mused. “They’re not very long-range transmitters.”

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« Reply #7167 on: Jul 09, 2020, 03:35 AM »

Country diary: the ‘lady of the house’ has been left to her fate

Wenlock Edge, Shropshire: This battered scarlet tiger moth has seen off predators and survived injury, but its defence strategies are failing

Paul Evans
Published on Thu 9 Jul 2020 05.30 BST

The moth looks moth-eaten. Its magpie white splashes on iridescent black forewings and its scarlet hindwings are distressed. It flutters erratically, unable to lift off from wet grass. Coaxed on to a leaf and transferred to the safety of a hedge, it soon struggles back to the same spot on the ground, as if awaiting its doom. Linnaeus named the scarlet tiger moth Callimorpha dominula, the “lady of the house”. This “lady” looks as if something terrible has happened to her and she is abandoned to her fate a long way from home.

Scarlet tiger moths are usually flyers of marshy places, fens, riverbanks and coastal wetlands, but they are sometimes found in gardens and along ditches. Their principal larval foodplant is comfrey and the caterpillars also feed on nettle, hemp agrimony and meadowsweet. They fly by day and by night, and maybe this ability and widening choice of habitats and food plants is helping them adapt to climate change and extend their range northwards from south-west England and Wales. It has certainly been suitably damp for them recently, but the adult moth only lasts a fortnight and, reaching the end of its flying period, is exhausted. This one’s wing damage may have been caused by birds or bats, and its sophisticated defence strategies are failing.

The distinctive colours of tiger moths are aposematic, a warning to predators of toxicity; the hairy white and yellow caterpillars contain neurotoxins (best to leave them alone). However, warning colours do not work in the dark and so these moths have developed an acoustic signal of alarm snaps that advertise their unpalatability and a biosonar jamming system that disrupts bats’ ultrasound.

Scarlet tiger moths can also be yellow, and the variability of colours and patterns in their populations has led to decades of research about whether evolution occurs principally through natural selection or from a neutral process called genetic drift – fluctuations in gene variants passed on by “lucky” individuals rather than healthier, “better” individuals.

Perhaps, despite being battered, this burlesque “lady of the house” is luckier than other scarlet tigers; maybe surviving this long against predators and the pervading weirdness is a sign of being better, but it feels like the tragedy of heroism.

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