Tag: Nature

Fire Ants Can Build Roiling Ant Towers To Get Around

fire ants

Ants don’t just build complicated nests. They’ll use their own bodies to make things, too. Researchers at Georgia Tech University are studying how the insects link together to make ant rafts and ant bridges.

Now, they’ve accidentally found that fire ants can also get around by using themselves to constantly build and rebuild a moving tower.

Researchers filmed fire ants climbing on top of each other and left the cameras rolling. When they watched the sped-up footage, they found the ant structure sinks under its own weight, so the insects constantly renewed the tower until they went where they wanted to go.

They fed ants radioactive food and watched them build towers in an X-ray machine so they could watch the interior of the tower sink as it grew. Ants that got pushed to the bottom eventually disengaged and started climbing again.

Behavior like this serves a purpose: Fire ants in their natural habitat in Brazil have to deal with frequent flooding. Rafts and towers are a way to escape water and relocate to a new home.

fire ants

It’s worked so well it’s kept ants alive for millions of years all over the world — and in Georgia Tech’s buildings, where they’ve been known to escape labs and set up camps under staffers’ desks.

nd designs based in biology could make our own construction more efficient. Scientists think ant building-techniques like this replenishing trick could be useful for self-assembling robots in the future.

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Pass it on: New Scientist

The Mystery Of Blue Diamonds And Where They Come From Finally Solved

They are the world’s most expensive diamonds, with some stones valued at £100 million.

But until now nobody has known how rare blue diamonds are made or where they come from.

Now scientists have discovered that they are formed 400 miles down in the Earth, around four times as deep as clear diamonds, where the element boron combines with carbon in such extreme pressure and heat that it crystallizes into the world’s most precious stone.

And because boron is mostly found on the Earth’s surface, scientists believe that it must have travelled down into the mantle when tectonic plates slipped beneath each other.

Eventually volcanic action brought the diamonds up closer to the surface.

The study, published in the journal Nature, suggests blue diamonds are even rarer than first thought.

We now know that the finest gem-quality diamonds come from the farthest down in our planet.”  said Steven Shirey, of the Carnegie Institution of Science.

Blue diamonds have always held a special intrigue. The world’s most famous jewel, the Hope Diamond, which was once owned by Louis XIV, Marie-Antoninette, and George IV was said to be cursed with many of its owners and their families coming to a sticky – and often headless – end.

The postman who delivered the Hope Diamond to its current location in the National Museum of Natural History in Washington DC had his leg crushed in a lorry accident shortly after and then his house burned down.

But the value and rarity of blue diamonds makes them difficult to study and researchers at the Carnegie Institution have spent two years tracking down and studying 46 blue diamonds from collections around the world.

And they were looking for the rarest of blue diamonds, those which include tiny mineral traces called inclusions which hint at their origins.

These so-called type IIb diamonds are tremendously valuable, making them hard to get access to for scientific research purposes,” said lead author Evan Smith of the Gemological Institute of America, adding,

“And it is very rare to find one that contains inclusions, which are tiny mineral crystals trapped inside the diamond.”

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Pass it on: Popular Science

How People Really Lived During the Stone Age

cave man

The Paleo diet is just the beginning. It’s the gateway to an entire suite of lifestyle prescriptions devoted to mimicking the way our ancestors ate, moved, slept, and bred nearly 10,000 years ago in the Paleolithic era of hunting and gathering, an era Paleo followers associate with strong bodies and minds.

Members of this modern-day caveman community believe the path to optimal health is through eating only what our ancestors ate before modern agriculture and a shift to more sedentary ways.

Devoted proponents of a Paleo lifestyle not only subsist primarily on meat and eschew carbs; they also exercise in short bursts of activity intended to mimic escaping prey.

Even blood donation has become a Paleo fad among the most dogmatic of 21st-century cavemen, based on the notion that our ancestors were often wounded, making blood loss a way of life.

But new research reveals flaws in the logic behind these trends. As evolutionary and genetic science show, humans, like all other living beings, have always been a work in progress and never completely in sync with the natural world.


If we’re going to romanticize and emulate a particular point in our evolutionary history, why not go all the way back to when our ape ancestors spent their days swinging from tree to tree?

It is hard to argue that a simpler life with more exercise, fewer processed foods, and closer contact with our children may well be good for us, but rather than renouncing modern living for the sake of our Stone Age genes, we need to understand how evolution has—and hasn’t—suited us for the world we inhabit now.

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Ground-Cuckoos Have Learned How To Mimic The Sound Of Their Predators


Acoustic communication is particularly important in environments such as dense tropical forests, where the dim light constrains the efficacy of visual signals.

In these environments, complex species interactions could promote the evolution of acoustic signals and result in intriguing patterns of mimicry and convergence.

In the Neotropical region, Neomorphus ground-cuckoos frequently associate with herds of collared peccaries and white-lipped peccaries.

Bill clacking behavior in ground-cuckoos closely resembles the sound of teeth clacking in peccaries and these acoustic signals are used in agonistic and foraging contexts in both species.

Here we demonstrate that the acoustic characteristics of bill clacking in ground-cuckoos are more similar to teeth clacking of peccaries than to bill clacking of the more closely related Geococcyx roadrunner.

We propose that two hypotheses may explain the evolution of the clacking behavior in these taxa.


First, because peccaries are known to successfully ward off attacks from large predators to defend their herds, mimicking their clacking can deceive predators, either by triggering clacking from nearby peccaries, or making it appear to the predators that peccaries are present when they are not.

Second, ground-cuckoos and peccaries could mutually benefit from the use of similar signals to alert each other of the presence of predators. In this context, ground-cuckoos could serve as sentinels while peccaries could confer protection.

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Some Species Of Plants Are Sleeping To Cope With Climate Change

Buttercups are dormancy-prone plants.

Not all species flee rising temperatures.

As the mercury has inched upward across western North America over the last 40 years, many plant species have moved downhill, toward—not away from—warmer climates, according to the results of a new study.

The finding adds to growing evidence that temperature isn’t the only factor influencing how Earth’s life will respond to climate change.

Like animals, plants require specific environmental conditions—such as the right temperature, moisture, and light levels—in order to thrive.

Even small changes in environmental parameters can affect the reproduction and survival of a species.

As global temperatures rise, both animal and plant populations are projected to gradually shift toward northern latitudes and upward to higher elevations where temperatures are cooler in order to stay within their ideal range of environmental conditions.

In an effort to understand how plants may cope with changing climates, researchers at the University of Washington, Seattle, compiled geographic coordinate data for the locations of nearly 300 plant species within seven topographically distinct regions across western North America.

Ranging from the western Sierra Nevada mountain range in Nevada to the eastern Rocky Mountain Foothills of northern Canada, spanning the last 40 years.

They then compared these findings with changing climate conditions, such as temperature, rain, and snowfall. The study is the most extensive of its kind to date.

The results of the analysis were unexpected. More than 60% of plants shifted their distributions downward, toward warmer, lower elevations—despite significant climate warming across the regions under study, the team reported online on 24 July in Global Change Biology.

Even more striking, all plants within a region—regardless of species—moved in the same direction.

A Pogonia japonica flower. Pogonias are dormancy-prone plants.

A closer look revealed that the downhill movement of plants was likely driven by the changes in precipitation that accompanied warming temperatures.

Those regions that experienced less rain and snow at high elevations were those with plants shifting toward lower elevations with wetter climates.

Less snow in winter translates into less water in summer, resulting in water-stressed plants and downward shifts,” Harsch says.

Although plant populations are shifting downward toward greater water availability, they will also have to contend with an increasingly warming climate.

It’s a double-edged sword,” Harsch states, “as temperatures rise, water needs will also increase.”

A bee pollinating.

Although previous, smaller studies have also noted downhill movements in relation to water availability, others report uphill movements in relation to temperature, suggesting the direction of species movements is dependent on local environmental conditions as well as the types of species present.

These studies highlight the importance of understanding the complexities not only of future climate change but the climatological requirements of individual species,” says Anne Kelly, a plant ecologist at the Catalina Island Conservancy in Avalon, California, who was not involved in the work.

Future climate changes are projected to intensify precipitation patterns in western North America, leading to more pronounced shifts in plant distributions and potential subsequent effects on the wildlife that depend on them for food and habitat.

How we decide where to allocate limited resources such as money and manpower to conserve species in the face of long-term global warming is a primary concern right now,” Harsch notes.

“We can’t monitor all species everywhere, but, by identifying the factors responsible for environmental changes, we can begin to predict effects and prioritize conservation management choices.”

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Pass it on: Popular Science

Bug-Eating Bats Help Plants, According To Studies

While some bats — vampire bats — live up to their Halloween reputation of sucking blood out of animals with their fangs, many more bats subsist on a diet that is more appealing, at least in its effects on the environment.

They eat lots and lots of bugs.

In the tropics, bats eat so many bugs that they put a significant damper on the number of bugs crawling on plants, two studies report in Friday’s issue of the journal Science.

Bug-eating bats are thus a boon to farmers there, reducing the need for insecticides. The findings also highlight incomplete knowledge about the role bats play in many ecosystems.

Using their sonar-like abilities, many bats can snatch insects out of the air in pitch blackness.

There are a lot of bats around, and bats must eat lots of insects,” said Kimberly Williams-Guillen, a postdoctoral researcher at the University of Michigan and lead author of one of the Science papers.

But few scientists have tried to see whether bats have a discernible influence on insect populations. Further, because bats fly around at night, scientists sometimes forget about them entirely.

In earlier experiments, scientists covered some plants with netting and cages, protecting insects from being eaten, and then months and years later, they counted the number of insects on the caged plants versus those on uncaged plants.

Fewer insects crawled on the uncaged plants because, the scientists concluded, birds flying around during the day were eating a lot of them.

Dr. Williams-Guillen wondered if hungry nocturnal bats might perhaps account for part of the insect control effect.

Instead of snatching moths and other flying bugs in midair, some bats hang in a tree and, with their extra-sensitive ears, wait until they hear the chirp of a grasshopper — “or even the sound of a caterpillar chewing on a leaf,” Dr. Williams-Guillen said — and swoop down to snatch the morsel.

At an organic coffee plantation in Mexico, she and her University of Michigan colleagues conducted an experiment similar to the earlier ones, except they compared coffee plants caged only during the day, plants caged only at night, plants caged all day long and plants not caged at all.

What the researchers found was that bats accounted for a large part of the insect consumptions, especially during the wet season in summer, when bats reproduce and mother bats have to eat prodigiously to nurse their offspring.

The opposite is true during the winter months when an influx of migrating insect-eating songbirds arrive from the United States and Canada.

Bats are as important as birds in limiting the insects in these coffee plants,” Dr. Williams-Guillen said.

A second team of scientists led by Margareta Kalka of the Smithsonian Tropical Research Center performed a similar experiment, but in a natural forest in Panama.

No other study had ever measured the effects of bats’ insect consumption in a natural forest,” said Dr. Kalka, who had been among the first to realize the importance of bats in controlling insects on plants, after he observed them with night vision cameras.

The findings could have implications for farmers; the number of bats is believed to be declining in many parts of the world.

It could also influence the method of farming. The coffee plantation studied by Dr. Williams-Guillen grew coffee plants under a canopy of shade trees.

Higher yields of coffee can be grown by eliminating the shade trees — but fewer species of bats frequent such open plantations, and that could mean fewer bats eating the bugs and a greater need for pesticides.

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Shy Pangolins Need World Spotlight To Survive

Reclusive, gentle and quick to roll up into a ball, pangolins keep a low profile.

But they are also the world’s most heavily trafficked mammal, and experts at the Convention on International Trade in Endangered Species (CITES) conference this week are ringing alarm bells over their survival.

Demand for pangolin meat and body parts has fueled a bloodbath, and driven the scale-covered, ant-eating mammal towards extinction.

More than a million pangolins are believed to have been poached from the wild in the past decade.

Most are used to supply demand in China and Vietnam, where they are highly regarded as a delicacy and an ingredient in traditional medicine.

At the CITES meeting in Johannesburg, conservationists will discuss moving pangolins into the highest protection category, which bans all international trade.

The pangolin today is regarded as the most heavily trafficked mammal in the world,” CITES chief John Scanlon told AFP.

“There has been a massive surge in the illegal take of the pangolin for its meat and for its scales.”

Currently CITES allows for trade in pangolins but under strict conditions.

Existing laws are clearly failing to protect pangolins from the poachers. A complete international trade ban is needed now,” said Heather Sohl, WWF-UK’s wildlife advisor.

There are four species of pangolin in Africa and four in Asia. Watchdogs say those in Asia are being eaten to extinction, while populations in Africa are declining fast.

Research published in the early 2000s estimated populations in China to have declined by up to 94 percent, said Dan Challender, pangolin expert at the International Union for Conservation of Nature.

Pangolins are covered in overlapping scales, and have pink, sticky tongues almost as long as their bodies.

When physically threatened, they curl into ball, making it easy for them to be picked up by hunters and put into a sack. About the size of a small dog, they are solitary, mostly nocturnal and cannot be farmed.

“Pangolins are notoriously difficult to keep in captivity — they only feed on wild ants and termites, and they are extremely prone to stress and dehydration, so they die,” Ray Jansen, of the African Pangolin Working Group, told AFP.

In Chinese traditional medicine, pangolin scales are ground into a powder believed to cure conditions from headaches and menstrual cramps to nose bleeding and lack of virility.

The scales are sometimes even used as guitar plectrums. In traditional African culture, some people believe in keeping a scale in their pockets to ward off evil.

Zimbabweans used to present the mammals to President Robert Mugabe during his early years in office, but the practice has been discontinued.

In Shona and Zulu culture, a pangolin is regarded as the greatest gift you can bestow on a chief, statesman or an elder,” said Jansen.

Pangolin fat, blood and bones are also highly valued in African traditional medicine.

According to Jansen, in South Africa a pangolin can sell for anything between 10,000 rand ($730) to 80,000 rand ($5,800) depending on the client.

India, the Philippines, Vietnam, Nigeria, Senegal and the United States are co-sponsoring the proposal to impose a total ban on pangolin trade.

The CITES treaty, signed by 182 countries and the European Union, protects about 5,600 animal and 30,000 plant species from over-exploitation through commercial trade.

The 12-day conference started Saturday and will sift through 62 proposals to tighten or loosen trade restrictions on some 500 species.

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Pass it on: New Scientist

How Do Fireflies Glow? Mystery Solved After 60 Years

Think of the firefly abdomen like a black box of bioluminescence.

For around 60 years, scientists have known what basic ingredients go into the box—things like oxygen, calcium, magnesium, and a naturally occurring chemical called luciferin.

And they’ve known what comes out of the box—photons, or light, in the form of the yellow, green, orange, and even blue flickers you see dancing across your backyard on summer nights.

But until recently, the actual chemical reactions that produce the firefly’s light have been shrouded in mystery.

And scientists like Bruce Branchini at Connecticut College love a good mystery.

The way enzymes and proteins can convert chemical energy into light is a very basic phenomenon,” he says, “and we wanted to know how that biochemical process worked.”

In new research, Branchini and his colleagues did just that: They found an extra oxygen electron that’s responsible for the beetles’ summertime glow.

The discovery, published recently in the Journal of the American Chemical Society, provides the most detailed picture yet of the chemistry involved in firefly bioluminescence.

The conventional explanation of how a firefly turns its backside into a bioluminescent beacon has always troubled Branchini and other chemists. For starters, it shouldn’t work.

Specifically, two of the ingredients mentioned above—oxygen and luciferin—aren’t likely to react to each other in the way they would need to in order to produce light.

Understanding why this is gets complicated fast, but a simple explanation is that apples tend to only create chemical reactions with apples, while oranges tend to only create chemical reactions with oranges.

In other words, oxygen and luciferin are like apples and oranges.

Branchini’s experiments showed the oxygen involved in the firefly’s glow comes in a special form called a superoxide anion.

This extra electron gives the oxygen properties of both a metaphorical apple and a metaphorical orange.

This means that the molecule would, in fact, be able to cause a chemical reaction with the luciferin like scientists have suspected.

He adds that these superoxide anions could be the way bioluminescence works across nature, from plankton to deep-sea fish.

To me, chemically, this is the only way it makes sense,” says Stephen Miller, a chemical biologist at the University of Massachusetts Medical School who also studies luciferin and its potential uses for human health.

Miller, who was unaffiliated with the study, says it’s important to keep studying luciferin and bioluminescence because of their potential applications for medicine.

For instance, earlier this year, Miller was part of a team that used luciferin to detect specific enzymes in the brains of living rats, which could someday offer doctors another window into the human brain.

Firefly luciferin is already proving to be a useful tool in imaging human tumors and developing cancer-fighting drugs, says lead author Branchini.

Ultimately, though, “we just want to know how nature works,” he says. “The applications may or may not follow.

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Why Sloths Live Life In the Slow Lane

Forests cover more than one-third of the land on Earth, yet few vertebrates make the canopy their home, and even fewer subsist solely on a diet of tree leaves.

In a new study in American Naturalist, researchers from the University of Wisconsin – Madison explain why this lifestyle is so rare and why animals that live in trees and eat leaves tend to live life at a slower pace.

Those species that do take advantage of this niche do not often radiate afterwards; that is, they don’t diversify and take on a variety of specialized forms.

The energetic constraints of a leafy diet are thought to prevent such adaptive radiation.

Leaves are an energetically and nutritionally poor food source. Most animals that live off plant leaves tend to be large, such as moose, elk, and deer.

Leaves are everywhere, but you need pretty complex gut machinery to be able to extract energy and nutrients from them,” says Jonathan Pauli, one of the study’s authors.

Most herbivores are big-bodied and they carry around big guts to break down and detoxify plant leaves.”

But animals that live in the treetops cannot be too big, or else the branches won’t support their body weight. So how do they make it on a nutritionally challenging diet?

Pauli and Zachariah Peery, along with co-authors Emily Fountain and William Karasov, set out to answer this question by measuring the daily energy expenditure of both two-toed and three-toed sloths in Costa Rica.

Both species of sloth are at the extreme end of specialization for a tree-dwelling, leaf-eating, lifestyle.

Pauli, Peery, and colleagues found that both sloth species expended very little energy, but three-toed sloths were especially slothful.

Three-toed sloths expended as little as 460 kilojoules of energy a day, the equivalent of burning only 110 calories. It is the lowest measured energetic output for any mammal.

Three-toed sloths use both behavioral and thermal strategies to limit their energy output. “They really are a slothful bunch,” says Pauli.

While two-toed sloths have bigger home ranges and move around quite a bit, three-toed sloths have very small home ranges and spend most of their time in just one or a few individual trees. “

“To limit energy costs, three-toed sloths find a good tree and camp out for a while and eat from it.”

The researchers then compared their sloth data to similar studies of other tree-dwelling, leaf-eating species from around the world.

Overall, the more specialized for the niche an animal was, the lower its daily energy expenditure.

While these species had lower metabolic rates than most mammals in general, they also relied heavily on thermoregulation and behavioral strategies to reduce their energetic expenditure.

The findings support the idea that tree-dwelling, leaf-eating mammals are tightly constrained by the poor nutritional quality of their diet, and thus, exhibit extremely low energetic output.

The researchers believe this impedes the opportunity for organisms to rapidly radiate into this niche.

For tree-dwelling, leaf-eating animals, there is a whole series of key innovations that are needed before they can crack into that open niche.

Sloths are the poster children for making a living in the treetops by saving energy. For them, slothfulness is a necessary virtue, not a deadly sin.

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Scientists Are Delighted To Discover That Eleanor The Sea Turtle Survived Unscathed After Tropical Storm

As seas get warmer, Earth is experiencing more powerful storms and hurricanes.

There are consequences for both humans and animals, and one of the concerns is marine animals – especially endangered species such as certain whales, manatees, sharks and sea turtles.

But new research has revealed that severe weather is not necessarily harmful to individual adult sea turtles – when researchers tracked a sea turtle during a tropical storm, they found that she survived the storm without any problems.

A team of Danish, American and Australian researchers conducted a study in 2012 which involved monitoring sea turtles fitted with GPS transmitters and motion sensors off the coast of Sarasota Florida.

One of the sea turtles, a loggerhead named Eleanor, was unexpectedly caught in a tropical storm, giving the researchers a unique opportunity to see how a sea turtle would cope with a storm.

We were delighted to find that she rode out the storm in style without any problem,” says Maria Wilson, a biologist at the University of Southern Denmark (SDU).

We know little about how sea turtles manage during hurricanes and tropical storms.

Storms could blow sea turtles off course, or surviving a storm could be so exhausting that it drains energy reserves and thus the ability to survive and produce eggs, thereby having a negative impact on the next generation of sea turtles,” explains Wilson.

A team of Danish, American and Australian researchers conducted a study in 2012 which involved monitoring sea turtles fitted with GPS transmitters and motion sensors off the coast of Sarasota Florida.

One of the sea turtles, named Eleanor, was unexpectedly caught in a tropical storm, giving the researchers a unique opportunity to see how a sea turtle would cope with a storm.

Eleanor was tagged for 16 days, four of which were during the storm, and data from the GPS and animal motion tags showed that she drastically changed behavior when the storm struck.

She was inactive for most of the first 9 days, during which she rested at on the seabed 80 per cent of the time with low levels of oxygen consumption.

Eleanor the sea turtle was caught in tropical storm Debby, which passed through through the Mexican Gulf between June 23 – 27, 2012 and caused extensive flooding in Florida, reaching wind speeds of up to 100 kph.

She was at sea in the Mexican Gulf in the egg-laying season when she was hit by the storm, and consequently, she had already nested on one of Florida’s beaches and had returned to the sea to replenish her energy reserves before coming back to lay more.

Eleanor was tagged for 16 days, four of which were during the storm, and data from the GPS and animal motion tags showed that she drastically changed behavior when the storm struck.

Before the storm, she rested on the seabed, moving only to go to the surface air.

When the storm struck, she moved further North than the researchers expected because she was forced by prevailing currents.

She also changed her diving patterns, becoming much more active instead of saving energy for the next egg-laying event.

Even though Eleanor swam for most of the four days the storm raged, she was good at saving energy, ending up actually using no more than she would normally use to produce 12 eggs,” says Wilson.

Given that sea turtles lay somewhere between 300 and 900 eggs during a nesting season, that’s not much.

The researchers calculated Eleanor’s energy consumption based on motion sensors (3D accelerometers and gyroscopes – a device used to measure orientation), which detected when she was swimming.

How much energy a swimming turtle uses had been determined from earlier experiments in the laboratory, making it possible to estimate how much energy they use at sea.

Even though it may seem that sea turtles are robust enough to avoid being harmed during storms, such a powerful storm can still be a major threat to them.

Sea turtles lay their eggs on the beach, and their nests are extremely vulnerable to passing storms,” Wilson says.

The storm that Eleanor easily survived destroyed almost 90% of nests on the beach where she and several hundred other female turtles had laid their eggs.”

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