By Tara Lohan
As we work to limit the spread of the COVID-19 pandemic, scientists are also studying its origins. How did the SARS-Co-V-2 virus, which causes the disease, jump from wildlife to humans? Many believe it originated in horseshoe bats (from the genus Rhinolophus), which are known hosts of other coronaviruses.
"Whether or not this particular strain came from a wild bat is still under active scientific investigation," said Winifred Frick, a professor of ecology and evolutionary biology at the University of California Santa Cruz and the chief scientist at Bat Conservation International, an organization dedicated to preventing bat extinctions worldwide.
Scientists are also trying to pinpoint which animals, including perhaps pangolins, may have been the intermediary pathway for the spillover. But one thing is certain: Bats play critical, and beneficial, roles in the environment and the economy.
And right now they're getting a pretty bad rap.
We spoke to Frick about why bats and other wildlife shouldn't be scapegoated in this pandemic, the threats bats face from humans, and the best actions to take for bat conservation.
Bat Conservation International's chief scientist Winifred Frick. Winifred Frick
Given what we know so far about the origins of the virus, should people be scared of wild bats?
In zoonotic disease, what happens is that you have viruses that are circulating naturally in wildlife populations. And then an event happens in which that virus spills over into the human population. If that pathogen starts to spread human-to-human, then we have a zoonotic disease outbreak.
It's important to remember that COVID-19 is at this point a human disease and it's being transmitted human-to-human. So nobody living here in North America needs to be worried about getting COVID-19 from a bat.
I think that we really want to allay concerns that people need to fear bats. There's definitely been some fear that has arisen because people hear that bats are somewhat associated [with the pandemic] and then that leads to misunderstanding.
Our general guidance is that people shouldn't be handling bats or wild animals of any kind.
There was a recommendation from the federal government that scientists may need to limit their fieldwork with bats in North America now to prevent a possible transmission of the virus from humans back to species of bats here. Is that a concern?
There is some concern about "reverse zoonosis" or spill back, which is the idea that humans could transmit SARS-Co-V-2 back to wildlife populations.
Researchers are working really hard to understand the vulnerability of other mammals to this novel strain of coronavirus. There was news about a tiger at the Bronx Zoo testing positive and some evidence that different mammals may be susceptible. We really want to make sure that we're protecting bats, which are mammals like us, from any risk from an asymptomatic human.
Just as we don't want people to spread this virus human-to-human, we don't want people to spread this virus human-to-wildlife. This isn't necessarily a specific concern about bats but really any mammal. We don't know yet if mammals could start to transmit animal-to-animal within their own populations. But right now we really want to limit exposure and limit any risk since we are still in an active research phase.
Have you seen much bat backlash?
There's some evidence that there's been some efforts to kill bats in different parts of the world. And we're very concerned about that. Bats are an important part of our ecosystem. They're incredibly biodiverse. They account for about 20 percent of all mammals globally. A lot of people don't realize that there's more than 1,400 different species of bat around the world.
And they have an enormous variety of ecological roles — what we call "ecosystem services." Here in North America, bats are primarily insect-eating and it's been documented that they provide in the billions [of dollars of benefit] for the agricultural industry in terms of their role in reducing crop predation.
It's #BatAppreciationDay! Bats have huge ecological and economical value. A 2013 study estimated that in the US al… https://t.co/vCIRaG3clT— AustralasianBatSoc. (@AustralasianBatSoc.)1587108341.0
In tropical areas bats are important dispersers of seeds and pollinators of different plants, some of which have real commercial value. For example, durian, which is the most stinky fruit and a treasure in many Asian cultures, is pollinated by bats. The agave, which is the plant that produces tequila, is pollinated by bats. So, they play very vital roles in nature and also have real economic value to human society.
Bats used to have a bad rap, but more and more, people seem to really realize just how fascinating and incredible they are. But because of some of those longstanding fears — and this new outbreak — we have to remind people that bats are really important parts of our ecosystem and part of our biodiversity heritage.
What kind of threats do bats face from us?
Globally bats face a variety of different threats, including anthropogenic land-use change, and habitat destruction and degradation. Because many species of bats form large colonies underground, those can be targets for disturbance and indiscriminate killing.
That's the one that we're really worried about right now. If people start to fear bats, we could see an uptick in directed killings. We're very concerned about that and very focused on trying to provide accurate information and also roost protection.
And of course white-nose syndrome is a major threat to our hibernating bats here in North America. It's a fungal pathogen that was likely introduced here through human trade or travel. The fungus is widespread in Europe and into temperate Asia. When it was introduced here, it spread very rapidly and has killed millions of bats.
And, unfortunately, you can't tell bats to social distance.
What can we be doing right now to help bats?
The number-one thing that people can do is to say positive things about bats and make sure we aren't scapegoating wildlife. There's a lot of evidence that zoonotic diseases are a reflection of our misuse of the planet. When people are destroying habitats and unsustainably harvesting species, those are the conditions that lead to these kinds of spillover events. And now more than ever, I think there is that recognition that human health and planetary health are intertwined and that wildlife conservation is a part of global health solutions.
Because bats do carry coronaviruses in the wild, and they have been talked about in the context of the COVID-19 pandemic, it's really important that people speak up for bats. This is not the bats' fault. This is our fault.
Reposted with permission from The Revelator.
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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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