Bug vs. Bird: Praying Mantises Feast on Feathered Prey

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Bug vs. Bird: Praying Mantises Feast on Feathered Prey

A praying mantis (Tenodera sinensis) eating a ruby-throated hummingbird (Archilochus colubris) in Illinois.

Credit: Courtesy of whatsthatbug.com/Randy Anderson

Many bird species are known to dine on insects, but for a dozen species of praying mantises, birds aren’t the predators — they’re the prey.

Carnivorous mantises are deadly hunters that use their powerful front legs to capture insects and spiders; some larger species have even been observed nabbing small vertebrates, such as amphibians, lizards, snakes and mice.

And now, scientists have found that mantises distributed around the world are also regularly catching and eating small birds, according to a new study. The researchers discovered 147 examples of mantises hunting birds in 13 countries, on every continent except Antarctica. [Lunch on the Wing: Mantises Snack on Birds (Photos)]

To gather their data, the researchers scoured extensive records of mantises preying on birds, delving into published studies, academic dissertations, books and posts on social media. The earliest description they found — from Argentina — dated to 1864, but 67 percent of the observations took place between 2000 and 2015, mostly in warmer climates, the researchers wrote in the study.

More than 70 percent of all the examples were from the United States, and the birds most often on the menu were ruby-throated hummingbirds (Archilochus colubris), which the mantises frequently captured near flowers and hummingbird feeders, the study authors reported.

As ambush predators, mantises lie in wait until their prey is close. They hold fast to a perch with four hind limbs as they strike with their front legs, and they begin to feed on the living victim once it is in their grasp. In some cases, the birds’ brains appeared to be a favorite part of the meal, the scientists wrote.

One account dating to 1922 in Australia described an unidentified mantis near four dead birds, “each with a hole in its head through which its brains had been extracted,” the study authors wrote.

In total, about 24 species of birds were identified as mantis prey. This group included hummingbirds and small passerines — perching birds such as sparrows, finches and canaries. And once a bird was caught, its fate was as good as sealed, with only 2 percent able to free themselves from the insect’s clutches without human intervention, the scientists found.

Most of the birds caught by mantises were relative lightweights, weighing in at less than 0.2 ounces (6 grams). By comparison, some of the mantis species weighed as much or slightly more than their prey. But mantises are also known for their ability to snag meals larger and heavier than they are. A prior study reported a mantis in Australia catching a tree frog that weighed 0.9 ounces (25 g), and another study described a mantis “attempting to chew on the wing” of a bird that weighed 0.5 to 0.7 ounces (14 to 19 g), according to the study.

A female <i>Tenodera sinensis</i> eating an immature male ruby-throated hummingbird (<i>Archilochus colubris</i>) in Clermont, New Jersey, with a courting male on her back.

A female Tenodera sinensis eating an immature male ruby-throated hummingbird (Archilochus colubris) in Clermont, New Jersey, with a courting male on her back.

Credit: Todd Klein

The bird-hunting mantises that the researchers encountered were generally female, with bodies measuring at least 2.4 inches (6 centimeters) in length. In two instances, the hungry female mantis was found multitasking — feeding on a bird while simultaneously mating with a male, study lead author Martin Nyffeler, a senior lecturer in zoology at the University of Basel in Switzerland, told Live Science in an email.

Reproductive needs could possibly explain why only female mantises were discovered eating birds — they might require more energy, as female spiders do, prior to producing their eggs, Nyffeler said.

The scientists also learned that in North America, about 55 percent of the birds counted in the study fell prey to invasive species of mantises, which were introduced about 100 years ago, and which are both larger and heavier than native mantises.

Invasive or not, mantises probably aren’t catching nearly as many birds as domestic cats, which kill hundreds of millions of small birds each year in the U.S. alone. But the study’s findings suggest that mantises do present an unexpected and significant risk to bird populations around the world —particularly hummingbirds, the study authors reported.

“On a global scale, bird mortality caused by praying mantises might be rather insignificant compared to the losses caused by raptor birds and cats,” Nyffeler said in a statement.

“Notwithstanding that, if we limit our consideration to the suburban/urban areas in USA, we arrive at the conclusion that praying mantises pose a considerable threat to hummingbirds” he added.

Original article on Live Science.

Fire Ants Build Sinking ‘Eiffel Towers’ from Their Own Bodies

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Fire Ants Build Sinking ‘Eiffel Towers’ from Their Own Bodies

Fire ants can use their bodies to create “towering” towers.

Credit: Georgia Tech

Fire ants can build miniature look-alikes of the Eiffel Tower from their own bodies, and the insects perpetually rebuild the structures to save them from collapsing, a new study finds.

The insects crawl up and down these structures in a phenomenon that resembles a slow-motion water fountain in reverse, the researchers said.

The new study’s finding could help lead to swarms of robots that can use their own bodies to form complex 3D structures, the scientists added. [Mind Control: Gallery of Zombie Ants]

Fire ants (Solenopsis invicta) evolved in the Pantanal wetlands of Brazil. In 2011, Craig Tovey, a biologist at the Georgia Institute of Technology in Atlanta, and his colleagues discovered the way in which colonies of theseinsects can shape themselves into raftsthat can stay afloat for months.

Fire ants can use sticky pads at the ends of their feet to link to each other and form a pancake-shaped raft. The 2011 study found that each ant’s exoskeleton can trap air bubbles and become slightly water-repellent. Weaving a colony together leads to a more powerful waterproofing effect that keeps the raft dry while afloat in the water. [Video: Watch Fire Ants Build Rafts]

If the ant rafts find optimal spots to settle down, they can form bell-shaped towers that act as temporary shelters in the aftermaths of floods. These structures may each consist of hundreds of thousands of ants and reach more than 30 ants high; until now, it was a mystery how ants could build such tall structures from their own bodies without getting crushed, the researchers said in the new study.

Tovey and his colleagues accidentally found the secret to the tall structures while they were experimenting with fire ant colonies gathered from roadsides near Atlanta. The researchers made the discovery when “we accidentally left the video camera running for an extra hour after the ants had finished building their tower,” Tovey told Live Science.

Study co-author Nathan Mlot, also a biologist at the Georgia Institute of Technology, “was too good a scientist to discard data,” Tovey said. “But he didn’t want to waste an hour watching nothing happen. So he played the video at several times regular speed.”

To induce the ants to build towers, the researchers placed them in clear boxes that had plastic rods sticking up from their floors. These rods served as supports on which the ants could build structures made of themselves. In subsequent experiments, the towers the ants built ranged from 0.28 to 1.18 inches (7 to 30 millimeters) high and were built within 17 to 33 minutes. The researchers noted that such towers likely took on a bell shape because in that form, each component bears an equal load.

At high speed, the researchers could see that the towers are constantly sinking, as ants within the depths of the structures tunnel away from the piles of insects around them. However, the structures are constantly rebuilt, as ants scurry up the sides of the towers.

“I was most surprised that the ant tower perpetually sinks and gets rebuilt,” Tovey said. “I thought the ants stopped building once the tower was complete. The shape stays the same — who would guess that the ants circulate through an unchanging structure?”

To confirm their findings, the researchers mixed a mildly radioactive iodine-based dye into the drinking water of some of the insects and then put the colony in an X-ray machine to monitor the motions of the ants. “In real time, the surface ants block the view,” Tovey said. “Moreover, the sinking is too slow to detect.”

By placing transparent sheets of plastic on top of ants, the scientists found that each insect, which on average weighs about 1 milligram, can support up to about 750 times its weight and live to tell the tale. However, the experiments also suggested that in towers, each ant seems to feel most comfortable supporting up to three ants on its back — any more, and they simply give up and walk away, Tovey said.

The researchers noted these structures were built without a leader or coordinated effort. Instead, each ant just wandered aimlessly, following a certain set of rules that could help it construct towers. Computational models the researchers developed could accurately predict tower shapes and growth rates, the study said.

“To build their tall, solid, Eiffel Tower-shaped structure, the ants seem to be following the same simple behavioral rules that they follow to build a pancake-shaped floating raft on water,” Tovey said. “It is remarkable that the two large-scale shapes formed by the group of ants are dramatically different and achieve different functions, yet emerge from the same small-scale individual behaviors.”

The researchers now want to analyze “the bridges the fire ants make out of their bodies to traverse gaps in terrain,” Tovey said. “They are amazing. The ones in front hold each other, dangle downwards and outwards to the other side, and grip firmly at each end. The rest of the ants walk across the bridge. Then, the ants who compose the bridge deconstruct it starting from the first side, so at the end, all of the ants have reached the other side.”

Such research could help inspire the creation of swarms of robots that could build complex structures from their bodies, Tovey said.

“Robotics researchers have had some success getting a fleet of robots to form a two-dimensional pattern like a rectangle, but they have not figured out how to get robots to form a stable three-dimensional structure,” Tovey said. “This research may show how to do that.

“For example, suppose we send several hundred little robots through a small opening into a collapsed building to search for survivors, or to explore unknown terrain on Mars,” Tovey said. “Sometimes, the robots will have to work together to cross crevices or climb over steep obstacles. At other times, they should spread out. This research may help us understand how to design their individual controllers so they can cooperatively accomplish different tasks in different situations.”

Still, it may prove difficult creating robots that can do everything ants can do, he said. “Repeatedly drop an ant from 6 feet [1.83 meters], and it won’t get injured. Drop a robot from 6 feet a hundred times and good luck,” Tovey said.

The scientists detailed their findings online July 12 in the journal Royal Society Open Science.

Original article on Live Science.

New Island Pops Up Off the Coast of North Carolina

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New Island Pops Up Off the Coast of North Carolina

New Island Pops Up Off the Coast of North Carolina
A new sandbar island has cropped up over the past few months just off the coast of North Carolina. Photographer Chad Koczera couldn’t get to the island on foot, so he sent a drone into the skies to capture this stunning image of the newly-formed island.

Credit: Courtesy of Chad Koczera

A new island suddenly emerged from the sea just off the coast of North Carolina — but officials warn that the spit of land is too dangerous for humans to explore.

The new sandbar island seemingly sprang from the ocean in just a few weeks, the Virginian Pilot reported. The island, which is about 1 mile (1.6 kilometers) long and about 480 feet (146 meters) wide, lies off the coast of Buxton, North Carolina, which is part of the Cape Hatteras National Seashore.

The new island grew from a mere nubbin in the ocean in April to its current size over Memorial Day weekend. One of the early explorers of the island, Janet Regan, took her 11-year-old son there to collect seashells. Because of its treasure trove of shells, the boy named it Shelly Island, the Pilot reported. [See Images of a Volcanic Island Birthed in Japan]

While the newborn island may be tantalizing for would-be explorers, it’s also very dangerous, Bill Smith, president of the North Carolina Beach Buggy Association, told the Pilot. Officials with the Cape Hatteras National Seashore have warned people not to try to reach the island.

Because the island formed near a popular fishing spot, years’ worth of fishing hooks could be lurking just below the sand. Sharks and stingrays prowl just beneath the water’s surface in the area, and the narrow 50-foot (15 m) strip of water between the island and the mainland forms a little “river” that creates a strong rip current, he said.

“We’re worried about shark bites, but we’re more worried about drownings,” Smith said.

The sandbar isn’t accessible by foot, so photographer Chad Koczera sent a drone into the skies to capture a stunning aerial photo. More intrepid (or foolhardy) explorers also have tried to reach the island by boat or paddleboard, the Pilot reported.

The area of coastline near the island is always transforming, according to a statement from the Cape Hatteras National Seashore. The point, called Cape Point, sometimes changes orientation, and currents and storms are constantly shaping the land. It’s likely that such forces formed the sandbar, meaning it could get even bigger or sink beneath the waves in the next year or two, Smith said.

If anyone does attempt a trip to the island, National Seashore Superintendent David Hallac said such a trip “is best accomplished by experienced kayakers or paddle boarders that are using appropriate flotation and mindful of the tides and strong currents in the area.”

Originally published on Live Science

Photos of Siberia’s Mysterious Craters

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Photos of Siberia’s Mysterious Craters

Seven giant craters have mysteriously appeared in northern Siberia, possibly due to methane gas released from melting permafrost. Check out these jaw-dropping photos of the strange geological structures. [Read full story about the Siberian craters]

This crater, in the Yamal Peninsula, was discovered in 2014 by helicopter pilots 19 miles (30 kilometers) from Bovanenkovo, a major gas field in the Yamalo-Nenets autonomous district. (Image credit: Marya Zulinova/The Siberian Times)

Four Arctic craters can be seen in this satellite image: B1, the famous Yamal hole located 19 miles (30 kilometers) from Bovanenkovo; B2, the recently discovered crater located 6.2 miles (10 km) south of Bovanenkovo; B3, a crater located 56 miles (90 km) from Antipayuta village; and B4, a crater located near Nosok village, north of the Krasnoyarsk region near Taymyr Peninsula. (Image credit:Vasily Bogoyavlensky)

Satellite image of the site before the formation of the Yamal hole (B1). K1 and the red outline show the hillock formed before the emission of methane gas. Yellow outlines show potentially dangerous areas where gas could erupt. (Image credit: Marya Zulinova/The Siberian Times)

Satellite images showing a mound of Earth before the gas emission that formed crater B2 (top). Lakes formed at a couple of the craters, and more than 20 smaller craters were found nearby (bottom). (Image credit: Marya Zulinova/The Siberian Times)

The Yamal lake showing signs of gas emission. (Image credit: Marya Zulinova/The Siberian Times)

Crater B3, located 56 miles (90 km) from Antipayuta village, Yamal district (top). Crater B4, located near Nosok village, north of the Krasnoyarsk region, near Taymyr Peninsula. (Image credit: local residents/The Siberian Times)

The ring of soil around these craters suggests an underground explosion. (Image credit: Vasily Bogoyavlensky/The Siberian Times)

The Russian Center of Arctic Exploration embarked on an expedition to Yamal crater in early November 2014. The researchers were the first in the world to climb down into the crater. (Image credit: Vladimir Pushkarev/The Siberian Times)

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Oozing Methane Blasts Holes in Siberian Tundra

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Oozing Methane Blasts Holes in Siberian Tundra

A crater on the Yamal Peninsula in Siberia, reported in the spring of 2017.

Credit: Itar-Tass/Zuma

Escaping methane gas has blown at least two new holes in the Siberian tundra in the past few months, according to eyewitness accounts to the Siberian Times and the Russian Academy of Sciences.

Reindeer herders northwest of the village of Seyakha in Siberia’s far north reported seeing an eruption of fire and smoke on the morning of June 28 — an event caught on seismic sensors at 11 a.m. local time, according to The Siberian Times. Scientists visiting the site photographed a fresh crater blown into the banks of a river.

Researchers also discovered a second, previously unknown crater in the Tyumen region of Siberia this month, the newspaper reported. Local herders told Aleksandr Sokolov, a researcher at the Institute of Ecology of Plants and Animals in Russia, that they’d observed fire in the area of that crater in the winter or early spring.

When permafrost melts, it releases large amounts of methane. According to Russian scientists, this sudden release could have led to the explosions. How fast and how frequently this is happening remain controversial topics in the scientific community, given that Siberia is so remote and unexplored. But scientists do agree that Siberia’s permafrost is in danger of melting as the globe warms.

Permafrost is soil that stays frozen all year long. Any organic matter, like dead grass or animal corpses, caught up in permafrost stays frozen, too. But as the Arctic warms, the depth of the spring thaw gets deeper and deeper — a process called active-layer deepening. As the soil thaws, the organic material locked inside begins to decompose all at once, releasing flammable gases such as methane, University of Michigan postdoctoral researcher Ben Abbott told Live Science in March.

In some cases, this release is slow, Abbott said. Other times, the soil can collapse dramatically, creating features called thermokarsts. These can look like landslides, slumps, pits or craters. Some fill with water and become lakes.

Past research suggests that warming can cause explosive changes in the landscape. A study released in June found that at least 100 giant cratersformed in one region on the Arctic seafloor about 11,600 years ago as the ice sheet retreated and destabilized mounds of frozen methane underneath. These mounds, call pingos, sometimes blew craters up to 0.6 miles (1 kilometer) wide into the ocean bottom.

Some Arctic scientists think something similar is happening in Siberia today. Pingos, or soil-covered permafrost hills, occur on land, too. If they melt rapidly, they could release a fiery burst of methane and create craters similar to the ancient ones seen on the seafloor. Previously, Siberian researchers had discovered craters that had never been seen before, but they had not published any information on the ages of the craters or scientific analyses of how they’d formed. The new eyewitness accounts from local herders suggest that the formation of these craters may, indeed, be violent.

Though the region of Siberia where these craters are located is remote, Russian authorities are concerned about the explosions caused by melting permafrost. The crater that formed on June 28 is about 60 miles (100 km) from Sabetta, a newly developed port on the Ob River that’s used to transport liquefied natural gas from the Yuzhno-Tambeyskoye gas field, The Siberian Times reported.

“It is very important for us also to know what to do, because such an eruption can occur anywhere,” Alexander Mazharov, deputy governor of the Yamalo-Nenets autonomous region in Siberia, told The Siberian Times. “It might hit a technical facility, a residential settlement or a linear object,” he said, referring to a pipeline or railroad.

Original article on Live Science. 


How Bad Is Gonorrhea’s Resistance to Drugs? Some Cases Are Untreatable

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How Bad Is Gonorrhea’s Resistance to Drugs? Some Cases Are Untreatable

How Bad Is Gonorrhea's Resistance to Drugs? Some Cases Are Untreatable

This illustration shows a computer-generated image of drug-resistant Neisseria gonorrhoeae, the bacteria that cause gonorrhea.

Credit: CDC/James Archer

The sexually transmitted disease gonorrhea is becoming increasingly more difficult, or at times even impossible, to treat because strains of the bacteria that cause it have become resistant to antibiotics, according to a new report.

In the report, researchers looked at data from gonorrhea cases and antibiotic resistance from 77 countries. Of all countries that reported such data between 2009 and 2014, 97 percent reported cases of the disease that were resistant to the gonorrhea treatment ciprofloxacin, 81 percent reported cases that were resistant to another treatment called azithromycin, and 66 percent reported cases that were resistant to the treatment called cephalosporin, the researchers found.

“The bacteria that cause gonorrhea are particularly smart,” Dr. Teodora Wi, medical officer of human reproduction at the World Health Organization (WHO), who co-authored the report, said in a statement. “Every time we use a new class of antibiotics to treat the infection, the bacteria evolve to resist them.” [27 Devastating Infectious Diseases]

Some countries with good surveillance of the disease have reported cases of gonorrhea that were resistant to all known antibiotics, according to the report. “These cases may just be the tip of the iceberg, since systems to diagnose and report untreatable infections are lacking in lower-income countries where gonorrhea is actually more common,” Wi said.

About 78 million new gonorrhea cases are diagnosed each year worldwide, the researchers said. Reports from many countries with good surveillance of the disease have suggested that gonorrhea has been on the rise, the researchers said. For example, the number of gonorrhea cases in the United Kingdom increased by 11 percent between 2014 and 2015, according to the report. The global increase in gonorrhea cases has been partially due to decreasing condom use, increased travel, low rates of gonorrhea-infection detection and inadequate treatment, the researchers said.

Complications from gonorrhea can be particularly dangerous for women, increasing their risk of developing pelvic inflammatory disease, infertility, HIV infection and ectopic pregnancy (where a fertilized egg grows outside the uterus), the researchers said.

Gonorrhea’s resistance to antibiotics has been spreading the most in Asia, North America, Europe, Latin America, the Caribbean and Australia, according to the report.

Researchers are testing three new potential drugs for gonorrhea treatment: solithromycin, zoliflodacin and gepotidacin, the researchers said. Pharmaceutical companies may not be eager to invest in developing new gonorrhea treatments, because such treatments are taken for only short periods of time, which makes them less profitable than, say, treatments for chronic diseases. Moreover, the effectiveness of the drugs wanes as the bacteria develop resistance, which in turn feeds the need to constantly develop new drugs to treat gonorrhea, the researchers said.

Many people who contract gonorrhea show no symptoms, and so they do not get diagnosed or treated, the researchers said. [6 Superbugs to Watch Out For]

Another problem is that people may have symptoms such as a discharge from the urethra or the vagina, which can be due to other conditions besides gonorrhea. Doctors may assume this symptom is due to gonorrhea and prescribe antibiotics to treat it, but this only perpetuates the cycle of antibiotic misuse and antibiotic resistance, the researchers said.

“To control gonorrhea, we need new tools and systems for better prevention, treatment, earlier diagnosis, and more complete tracking and reporting of new infections, antibiotic use, resistance and treatment failures,” Dr. Marc Sprenger, director of antimicrobial resistance at WHO, said in a statement. Some of these tools include new antibiotics, improved diagnostic tests and a vaccine to prevent the disease, he said.

Originally published on Live Science.