The ghoulishly named ogre-faced spider can "hear" with its legs and use that ability to catch insects flying behind it, the study published in Current Biology Thursday concluded.
"Spiders are sensitive to airborne sound," Cornell professor emeritus Dr. Charles Walcott, who was not involved with the study, told the Cornell Chronicle. "That's the big message really."
The net-casting, ogre-faced spider (Deinopis spinosa) has a unique hunting strategy, as study coauthor Cornell University postdoctoral researcher Jay Stafstrom explained in a video.
They hunt only at night using a special kind of web: an A-shaped frame made from non-sticky silk that supports a fuzzy rectangle that they hold with their front forelegs and use to trap prey.
They do this in two ways. In a maneuver called a "forward strike," they pounce down on prey moving beneath them on the ground. This is enabled by their large eyes — the biggest of any spider. These eyes give them 2,000 times the night vision that we have, Science explained.
But the spiders can also perform a move called the "backward strike," Stafstrom explained, in which they reach their legs behind them and catch insects flying through the air.
"So here comes a flying bug and somehow the spider gets information on the sound direction and its distance. The spiders time the 200-millisecond leap if the fly is within its capture zone – much like an over-the-shoulder catch. The spider gets its prey. They're accurate," coauthor Ronald Hoy, the D & D Joslovitz Merksamer Professor in the Department of Neurobiology and Behavior in the College of Arts and Sciences, told the Cornell Chronicle.
What the researchers wanted to understand was how the spiders could tell what was moving behind them when they have no ears.
It isn't a question of peripheral vision. In a 2016 study, the same team blindfolded the spiders and sent them out to hunt, Science explained. This prevented the spiders from making their forward strikes, but they were still able to catch prey using the backwards strike. The researchers thought the spiders were "hearing" their prey with the sensors on the tips of their legs. All spiders have these sensors, but scientists had previously thought they were only able to detect vibrations through surfaces, not sounds in the air.
To test how well the ogre-faced spiders could actually hear, the researchers conducted a two-part experiment.
First, they inserted electrodes into removed spider legs and into the brains of intact spiders. They put the spiders and the legs into a vibration-proof booth and played sounds from two meters (approximately 6.5 feet) away. The spiders and the legs responded to sounds from 100 hertz to 10,000 hertz.
Next, they played the five sounds that had triggered the biggest response to 25 spiders in the wild and 51 spiders in the lab. More than half the spiders did the "backward strike" move when they heard sounds that have a lower frequency similar to insect wing beats. When the higher frequency sounds were played, the spiders did not move. This suggests the higher frequencies may mimic the sounds of predators like birds.
University of Cincinnati spider behavioral ecologist George Uetz told Science that the results were a "surprise" that indicated science has much to learn about spiders as a whole. Because all spiders have these receptors on their legs, it is possible that all spiders can hear. This theory was first put forward by Walcott 60 years ago, but was dismissed at the time, according to the Cornell Chronicle. But studies of other spiders have turned up further evidence since. A 2016 study found that a kind of jumping spider can pick up sonic vibrations in the air.
"We don't know diddly about spiders," Uetz told Science. "They are much more complex than people ever thought they were."
Learning more provides scientists with an opportunity to study their sensory abilities in order to improve technology like bio-sensors, directional microphones and visual processing algorithms, Stafstrom told CNN.
"The point is any understudied, underappreciated group has fascinating lives, even a yucky spider, and we can learn something from it," he told CNN.
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By Karin Jäger
"They begin on a fall night, preferring the light of a full moon … Driven by the currents, they're pulled to the mouth of the river and out into the ocean," writes the WWF, rather poetically, of the European eel's long journey from the rivers of Central Europe to the far reaches of the Atlantic Ocean.
Think Beyond Borders to Protect Species<p>When an animal crosses so many territories, how can it be protected? That's where the Convention of Migratory Species (CMS), sometimes known as the Bonn Convention, comes in. Every three years, the European Union and an additional 129 countries signed up to the CMS meet to discuss cross-border measures to protect eels and other animals on the move.</p><p>In February 2020, the convention met in Gandhinagar, India, where 10 migratory species, including the Asian elephant, jaguar and the oceanic whitetip shark, were added to the international wildlife treaty for the first time.</p><p>Nature's travelers face specific challenges, particularly as humans encroach more on animal habitat and carve up the landscape with roads and settlements, say experts. Wildlife needs to be taken into consideration at the planning stages of such infrastructure projects.</p><p>"Improving connections between habitats is important if we want to stop or even reverse extinctions," said Arnulf Köhncke, an ecologist with conservation group WWF. "You need to look at where an area cuts through as few migration routes and habitats as possible and plan and implement corresponding, cross-border (wildlife migration) corridors."</p><p>Such planning also requires cooperation between states.</p><p>Several bilateral agreements to protect migratory species already exist within the framework of the Bonn Convention. For instance, Chile and Argentina have committed to saving the endangered south Andean deer, which moves up and down the South American Andes, crossing through both countries as it does.</p>
Unprecedented Global Biodiversity Loss<p>Not all animals move across borders of their own accord. International trade in animals also requires international protection efforts. In the case of the eel, considered a delicacy from Europe to Asia, criminals smuggle young European "glass eels" in and out of countries, although international trade is strictly regulated under CITES, an international treaty governing trade in wildlife.</p><p>The trade is in animals caught in the wild. Breeding eels in captivity has so far proved impossible because of their complicated life cycle, which until recently, scientists still knew little about.</p><p>It's a lucrative gig and one that is driving down eel numbers. Although, the trade is regulated, enforcement is often lacking. People should avoid eating the animals, according to WWF. And we should avoid consuming too much fish and meat in general to halt species loss, says the conservation group.</p><p>Veronika Lenarz, who works with the secretariat of the Bonn Convention, agrees. But several major countries, like the USA, Russia and China, aren't party to the convention, while Japan refuses to sign up because of its whaling industry.</p><p>"We are in a crisis that threatens global biodiversity," said Lenarz.</p><p>In a major assessment of the world's wildlife published in September 2020, the UN warned of "unprecedented biodiversity loss" and said the global community had failed to fully achieve any of the 20 biodiversity targets set by the international organization 10 years ago.</p><p>While migratory animals are also impacted, not enough is known about many of the species to gauge to what extent. Researchers estimate there could be anywhere between 5,000 to 10,000 migratory species, ranging from storks and butterflies, to dolphins and wolves.</p>
Climate Change: An Ever-Present Threat<p>Regions in which the climate is changing most rapidly and on a large scale present a particular danger for migratory species. The animals, following a deeply embedded evolutionary instinct, will search for seasonal habitats in search of food and shelter. However, food is increasingly scarce in these places due to climate change.</p><p>Some animals are adapting. Compared to 20 years ago, fewer migratory birds are flying to their wintering grounds. But because these nomads are dependent on the many different habitats they use as resting points on their journeys, they are more vulnerable than their settled counterparts. By staying put, they're also in increased competition for scarce winter food supplies.</p><p>And while animals can adapt, not many can keep up with the pace of climate change.</p><p>"Reports from the UN climate group IPCC show that only a few species can move with the speed of climate change. And often alternative habitats are already occupied by humans," said Köhncke from the WWF.</p><p>The climate crisis and species loss shouldn't be viewed as unrelated issues, because both are damaging to the planet, added Köhncke.</p><p>"Migratory species help to maintain life on Earth. They contribute to the structure and functions of ecosystems as pollinators and seed dispersers, deliver food to other animals and regulate the number of species," said Köhncke. </p>
Creating Conditions to Thrive<p>Ensuring the conditions for the survival of these species should be considered when planning measures for dealing with the consequences of climate change, he added, referring to the WWF study "Wildlife in a Warming World."</p><p>Published in 2018, the study found that around 50% of species in some of the world's key natural regions, such as the Amazon, could disappear if climate change continues unabated.</p><p>Reindeer for instance, some of which migrate in the northern hemisphere, are no longer able to find enough food. Usually in winter, the animals clear snow with their hooves to uncover the lichens and moss they feed on. But temperatures now vary wildly, causing snow to melt or fall as rain instead. When the ground cools again, ice forms and the reindeer cannot get to their grub. </p>
Simple Solutions to Protect Endangered Species<p>Looking to the example of Mexico, the International Fund for Animal Welfare (IFAW) has shown protecting endangered migratory species doesn't have to be complicated.</p><p>Industrial farming has contributed to the jaguar's habitat shrinking by 50% in South and Central America in the last century. As a result, they began roaming near villages looking for food and attacking villagers' dogs. People retaliated by killing them. The IFAW hired community members to build dog houses, meaning the canines are no longer out roaming at night when they could run into big cat predators.</p><p>However, with the global conservation failures of the past decade looming, all eyes will be on the UN Biodiversity Conference scheduled to take place in China in 2021 and whether it can pull off a plan for protecting migratory and non-migratory animals like.</p>
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The Trump administration formalized its intention to open up Alaska's pristine Tongass National Forest, an intact temperate rainforest, to logging and development, The Washington Post reported on Wednesday.
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Australian scientists have discovered a massive detached coral reef in the Great Barrier Reef. It is the eighth detached reef discovered in the northern Great Barrier Reef and the first to be discovered in over 120 years.
A newly-discovered 1,600-foot tall detached reef in the Great Barrier Reef was discovered, 3-D mapped and filmed by Australian scientists. Schmidt Ocean Institute
Scientists used a robot to capture video of the enormous detached reef found off Australia's northern coast. Schmidt Ocean Institute
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By Naomi Larsson
For centuries, the delicate silver dove has been a symbol of love and fidelity.
Biodiversity and Habitat Loss<p>Their near extinction is a symbol of the <a href="https://www.dw.com/en/global-biodiversity-outlook-targets-extinction-summit-new-york-pledge/a-54932895" target="_blank">biodiversity crisis</a> in the UK, largely driven by habitat destruction. Britain is now one of the countries with the most <a href="https://www.wwf.org.uk/future-of-UK-nature#:~:text=The%20UK%20is%20one%20of,than%20half%20are%20in%20decline" target="_blank">depleted nature</a> in the world according to the World Wildlife Fund. Half its plant and animal species are in decline and more than <a href="https://www.rspb.org.uk/about-the-rspb/about-us/media-centre/press-releases/let-nature-sing-wales/#:~:text=a%20natural%20tragedy.-,Over%2040%20million%20birds%20have%20vanished%20from%20UK%20skies%20in,unaware%20of%20the%20impending%20danger" target="_blank">40 million birds</a> have vanished in just half a century.</p><p>"[Turtle doves] are the canary in the [coal] mine because there are all these other species before it and after it," said Tree. "It's an umbrella for all the other species that are heading that way."</p><p>Turtle doves migrate south through Europe to sub-Saharan Africa between July and September, ending up in dry woodland and farmland areas of countries like Mali and Senegal for winter. </p><p>Droughts in West Africa and the Sahel region are believed to have contributed to the fall in turtle dove species recorded in northern Europe, with low rainfall reducing supplies of the seeds and insects the birds rely on for energy for the long journey home.</p>
Conservation and Farming<p><a href="https://www.operationturtledove.org/" target="_blank" rel="noopener noreferrer">Operation Turtle Dove,</a> a partnership project of charities including the Essex Wildlife trust, works with landowners and farmers to actively build turtle dove habitat.</p><p>Outten works with <a href="https://www.ebws.org.uk/birdsites/blue-house-farm-ewt-north-fambridge" target="_blank">Blue House Farm</a>, a 660-acre nature reserve in the UK county of Essex, where they have replicated weedy fallow plots. </p><p>"We work on it every year to make sure it's in the condition it needs to be with plants such as clovers and black medic," Outten said. "These plants are native to the landscape and produce the seed the birds feed on." </p><p>The birds eat a wide range of seeds from various plants that would have been abundant 50 or 100 years ago, added Guy Anderson, program manager for species recovery with The Royal Society for the Protection of Birds (RSPB). </p><p>"But it's simply true that with the gradual process of <a href="https://www.dw.com/en/farming-without-pesticides-how-can-we-make-agriculture-greener/a-52216796" target="_blank" rel="noopener noreferrer">intensifying our agricultural production</a>, the availability of those seeds has dropped and dropped," said Anderson.</p><p>Part of the project includes supplementary feeding — providing sources of food in the form of seed or grain. Under the Countryside Stewardship Scheme in England, farmers can receive financial support to create a turtle dove habitat. </p><p>Though they haven't recorded an increase in doves across the sites in the four years of working on the project, Outten said they are seeing improvements in how landowners and farmers manage habitat for the birds. </p>
A Turtle Dove Haven<p>The 3,500-acre Knepp Estate in West Sussex is another project taking a different approach and one of the few places where turtle dove numbers are increasing.</p><p>Isabella Tree and her husband Charlie Burrell converted their intensively farmed land into a rewilding project almost 20 years ago. They have let the land return to nature.</p><p>Just one year after they'd finished <a href="https://www.dw.com/en/uks-most-talented-architects-are-not-human/a-35952128" target="_blank">rewilding</a> the southern part of their property, they heard turtle doves for the first time. It's now a breeding hotspot for the birds with an estimated 19 pairs. Knepp is also home to <a href="https://www.rewildingbritain.org.uk/rewilding/rewilding-projects/knepp-estate" target="_blank" rel="noopener noreferrer">2% of the UK's population</a> of nightingales. </p><p>Tree is critical of supplementary feeding schemes that, in her view, are short term. She questions the chances of turtle doves getting to feed on scattered seeds before other mammals eat them first.</p>
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The aptly named diabolical ironclad beetle (Phloeodes diabolicus) has an exoskeleton so strong, it can survive being pecked by birds and even run over by cars. When early entomologists tried to mount them as specimens, BBC News explained, that exoskeleton would snap or bend their pins.
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A new report from the United Nations found that political leaders and industry leaders are failing to do the necessary work to stop the world from becoming an "uninhabitable hell" for millions of people as the climate crisis continues and natural disasters become more frequent, as Al-Jazeera reported.
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By Jodi Helmer
Bees are facing a pandemic of their own.
A collection of threats — habitat loss, pathogens, pesticides, pollution and poor nutrition — have led to widespread decline in bee health and pollinator populations.
USDA photo by David Kosling
An endangered rusty patched bumble. USGS Bee Inventory and Monitoring Lab
Rick Brohn / USFWS
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Scientists are racing to create a cure for COVID-19, but the toll on sharks might be irreparable. Conservationists estimate that half a million of the predators may be killed to supply the world with a coronavirus vaccine when one is developed.
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A grim new assessment of the world's flora and fungi has found that two-fifths of its species are at risk of extinction as humans encroach on the natural world, as The Guardian reported. That puts the number of species at risk near 140,000.
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A pygmy rabbit rescued from a breeding site in Beezley Hills, Washington eats owl clover in its new enclosure. Kourtney Stonehouse, WDFW
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