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Paul Allen's 'Great Elephant Census' Shows Catastrophic Decline in Africa

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Paul Allen's 'Great Elephant Census' Shows Catastrophic Decline in Africa

Results of a multiyear survey effort released Wednesday reveal that Africa's savannah elephants are far worse off than anticipated. A survey called the "Great Elephant Census" estimates that only around 352,271 elephants remain—down from previous estimates of 419,000 to 650,000 elephants in 2013. The report's authors estimate they recorded 93 percent of all savannah elephants in the survey. Elephants in Africa are threatened by poaching for their ivory, habitat loss and human encroachment and conflict.

"The Great Elephant Census is an amazing feat of technology and science working together for wildlife—but these results are shocking," Tanya Sanerib, a senior attorney with the Center for Biological Diversity, said. "Elephant populations in Africa are declining at an alarming rate and more severely than we anticipated."

In addition to presenting new survey data, the report uses existing data to estimate that from 2010 to 2014 savannah elephant populations decreased by 8 percent per year, roughly double the rate populations decreased annually from 2005 to 2010. Elephant carcasses—mainly from poaching but also natural deaths—were also surveyed and those results suggest that elephant deaths likely exceeded births. The carcass surveys raise even greater concern for the continued existence of savannah elephants.

"The data now clearly show that if we don't act immediately to stop poaching, close ivory markets and extend the strictest protections to elephants, we'll lose these iconic creatures forever," Sanerib continued.

The survey results do not include Namibia (which refused to release its survey results but is estimated to have more than 22,000 elephants, bringing the total to 375,000 elephants) or South Sudan and the Central African Republic, where surveys could not be completed due to armed conflict. The surveys were only conducted for savannah elephants and did not include forest elephants, a separate and smaller species inhabiting west and central Africa. Forest elephants could not be surveyed using the same aerial techniques due to the forested ecosystems they inhabit.

"Forest elephant populations are already known to be decreasing at alarming rates and now the Great Elephant Census has revealed that savannah elephants are in the same boat," Sanerib concluded. "A world without elephants would be a very sad place and it's time for international action on the ivory trade to make sure we never live in that world."

Eating too much black licorice can be toxic. Nat Aggiato / Pixabay

By Bill Sullivan

Black licorice may look and taste like an innocent treat, but this candy has a dark side. On Sept. 23, 2020, it was reported that black licorice was the culprit in the death of a 54-year-old man in Massachusetts. How could this be? Overdosing on licorice sounds more like a twisted tale than a plausible fact.

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A net-casting ogre-faced spider. CBG Photography Group, Centre for Biodiversity Genomics / CC BY-SA 3.0

Just in time for Halloween, scientists at Cornell University have published some frightening research, especially if you're an insect!

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.

Hoy agreed.

"The point is any understudied, underappreciated group has fascinating lives, even a yucky spider, and we can learn something from it," he told CNN.

Financial institutions in New York state will now have to consider the climate-related risks of their planning strategies. Ramy Majouji / WikiMedia Commons

By Brett Wilkins

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