- Brett Smith for redOrbit.com - Your Universe Online
Spiders have long been thought of as creepy-crawly predators, but a new study from a couple of European researchers has found that these arachnids will munch on pollen from time to time as well.
According to their report in the journal PLOS ONE, the study team found that the diet of younger, common orb-weaver spiders includes around 25 percent pollen. The spiders were even found to eat pollen when insect prey was readily available. While spider webs are most famously used to capture prey, they can also ensnare aerial pollen and fungal spores.
"Most people and researchers think of spiders as pure carnivores, but in this family of orb web spiders that is not the case,” said study author Dirk Sanders, an ecologist at the University of Exeter. “We have demonstrated that the spiders feed on pollen caught in their webs, even if they have additional food, and that it forms an important part of their nourishment.”
To make their discovery, the researchers performed feeding experiments and a stable isotope analysis on juvenile orb-weaving spiders to determine if they include plant resources in their diet.
“The amount of pollen consumption was quite similar in the laboratory and in the field, indicating that orb-weaving spiders actively feed on pollen for optimal nourishment, with all essential nutrients delivered by insect prey and resources provided by plants, at least at early life stages,” the researchers wrote in their report.
“Most pollen grains are too large to pass through the spider’s pharynx and therefore cannot be swallowed accidentally but have to be actively consumed,” the researchers concluded. “Spiders dissolve the outer coating of a pollen grain via extra-oral digestion and suck up the dissolved nutrients afterwards.”
“The pollen grains used in this study were of different shapes and sizes,” they added. “It is likely that other araneid species feed on different pollen. “
The research team found that providing their spiders with different diets did not affect weight gain in the juveniles.
“This suggests that when insect prey is also available, the supplement through pollen might not be important for spider growth, but it could have an effect on long-term fitness, i.e. reproduction and survival, as indeed pollen has been shown to increase the survival of otherwise starving spiderlings,” the scientists wrote. “Therefore, it is likely that pollen availability is crucial for spider survival at the early juvenile stage in spring, when insect prey is scarce in contrast to pollen.”
The research team concluded that the amount of pollen eaten by their spiders was so high that they should be reclassified as omnivores instead of carnivores.
“The question remains whether spiders choose their web building location based on pollen availability in the environment,” the researchers said. “The juvenile (orb-weaving spiders) we observed in this study had built their webs in the branchwood of different wind-pollinated trees. This could be due to the fact that these are optimal locations for successfully capturing flying insect prey; however it could also be possible that webs are positioned according to pollen availability and spiders select these locations as juveniles.”
“Further studies investigating pollen feeding at different life stages and in different habitats are needed to increase our understanding of the importance of herbivory for spider fitness, behavior and their role in ecological communities,” they concluded.
- Brett Smith for redOrbit.com - Your Universe Online
Thinking about joining Bilbo Baggins on his journey to the Lonely Mountain this weekend? If you are, a scientist from Bristol University in the UK has made it easy for you to dress for the weather.
British climate scientist Dan Lunt, under the pseudonym Radagast the Brown, has recently released a mock research paper detailing computer simulations for the climate of Middle Earth – the world created by J.R.R. Tolkien for his epic adventures, The Lord of the Rings and The Hobbit.
"The climate of Middle Earth has a similar distribution to that of Western Europe and North Africa," the report said.
The Shire, where both epic adventures began, is said to have a climate similar to the counties in the eastern UK. While Mordor, the hellish site of the final climatic scene in The Lord of the Rings, has a climate similar to western Texas or Los Angeles, according to the computer simulations.
To reach these conclusions, Lunt said he took Tolkien’s detailed maps of the landscape of Middle Earth and fed them into the Advanced Computing Research Center’s supercomputer at Bristol University, according to The Guardian. For the mock paper, Lunt had the computer produce a 70-year model.
"For a model to work, all you need is a map of where continents are, and how high the mountains are," Lunt said.
The UK scientist, and obvious Tolkien fan, even suggested that acclaimed director Peter Jackson chose the wrong New Zealand location when shooting scenes set in The Shire for both epic series.
"They made a mistake by filming in the north island – they should've filmed in the south island," Lunt said.
The paper also suggested that the Misty Mountains cast a "rain shadow" to the east, meaning the peaks in the range are so high – they prevent prevailing winds from carrying moisture to the east.
"It can be seen that there are strong westerly (i.e. coming from the west, towards the east) winds in the coastal southern regions of Middle Earth, in particular in the Bay of Belfalas," the paper said.
"Conversely, there are easterly winds in the north of Middle Earth,” the paper continued. “This may explain why ships sailing to the Undying lands to the West tended to set sail from the Grey Havens, situated in the region of these easterly winds."
While the mock paper may seem silly or even a waste of time to some, Lunt said his work isn’t without real scientific value.
"The serious side is that the climate models I used, and those (other models) out there, are actually based on our fundamental understanding of science, of fluid mechanics, fluid motion, the science of convection in clouds, radiation from the sun, and the science of biology,” Lunt wrote as his alter-ego Radagast the Brown. “And because of that, they're not just tuned for the modern earth, they can simulate any climate."
However, Lunt isn’t without a sense of humor – he also made the paper available in both dwarvish and elvish for those fluent in Middle Earth’s other languages.
- [ Watch the Video: Who (Or What) Is Behind The Mysterious Mima Mounds? ]
Brett Smith for redOrbit.com - Your Universe Online
The origins of Mima mounds, piles of dirt which can measure around 8 feet high, have baffled scientists for decades. Some have speculated they are Native American burial sites, but human remains have never been found inside the tiny hills.
Now, researchers have found gophers are most likely responsible for the earthen mounds, according to a report presented at the American Geophysical Union Fall Meeting in San Francisco on Monday.
The mounds were first discovered in 1841 in Washington State and have since been found all over the world.
"The big mystery surrounding Mima mounds is that, until now, nobody really knew how they formed,” report researcher Manny Gabet, of San Jose State University, told Rebecca Morelle of BBC News. "Over the past couple of hundred years, people thought they might be Native American burial mounds, or they were caused by earthquakes or glaciers. Some people even suggested extraterrestrials."
Using computer simulations, Gabet and his colleagues found the structures were actually created by the burrowing actions of gophers. In areas prone to waterlogging, the gophers slowly move small amounts of earth up toward the surface in an attempt to stay dry, the researchers found. Over the course of centuries, the little hillocks slowly form.
"I developed 'digital gophers' and had them behave like they do in real life, and to my surprise Mima mounds just started to form in this virtual landscape,” Gabet said. "The (computer) model results look so similar to the mounds in every way - not just the dimensions, but also the way they are packed and how many you get per area."
"It replicates the real-life situation almost perfectly,” he added.
A description of the report on the AGU website linked the mounds to the evolution of the subterranean mammals.
“Mima mounds are the largest structures built by non-human mammals, and may provide a rare example of an evolutionary coupling between landforms and the organisms that create them,” the description said.
However, gophers are only found in North America – meaning the origins of Mima mounds in other parts of the world are still shrouded in mystery. Gabet said other burrowing mammals, such as moles, could be responsible for the mounds found on other continents.
"Mima mounds in the US are infested by gophers," he said. "A good place to start would be to dig into these mounds (in other countries) and see what kind of critters are living inside of them."
The Mima mounds are thought to have been built by pocket gophers, which get their name from the large pouches found inside their cheeks. Weighing around 2 pounds as full-grown adults, pocket gophers use their cheek pouches to transport and hoard food in their burrows. A gopher often announces its presence with a mound of fresh dirt from which it has emerged. These mounds can appear in gardens or lawns, often to the chagrin of homeowners.
Pocket gophers are solitary outside of breeding season and have been known to aggressively maintain their territory. Occasionally, males and females will share the same burrow.
- [ Watch the Video: Belching For The Ladies, Koala-Style ]
April Flowers for redOrbit.com - Your Universe Online
Koalas have the appearance of a living teddy bear, inviting many of us to assume they are cute and placid. When mating season starts, however, the males produce a bellow that defies their size and cuteness.
As the males inhale, they make a sound somewhat like a creaky door, according to National Geographic reporter Ed Yong. Exhalations sound more like someone belching, with gusto. Yong says that together these noises create a continuous racket that sounds like an angry Wookie. Scientists and tourists alike are perplexed by the depth of these sounds. Koalas, with their tiny bodies, shouldn't be able to produce such a sound.
A new study, published in Current Biology, has discovered the secret to the koala's deep bellow: koalas have a specialized sound-producing organ that has never before been seen in any other land-dwelling mammal. The newly described organ is outside the voice box, or larynx.
"We have discovered that koalas possess an extra pair of vocal folds that are located outside the larynx, where the oral and nasal cavities connect," says Benjamin Charlton of the University of Sussex. "We also demonstrated that koalas use these additional vocal folds to produce their extremely low-pitched mating calls."
Generally, mammals create vocalizations using the larynx in their throats. As air passes through the larynx, a pair of membranes called the vocal folds are vibrated—creating sound waves in the nose and mouth. The pitch of those sound waves can be controlled by using muscles in the larynx to change the tension in the vocal folds, also known as the vocal cords.
[ Watch the Video: Understanding A Koala’s Voice ]
The size of a mammals vocal cords matters as well by setting the lowest possible noise that each animal can make. This explains why small mammals can only produce high-pitched squeaks, while large species can produce rumbling bass.
The koala, however, is an exception to this rule. The mating bellow of the male has a lowest pitch frequency of 27 Hertz—at least three octaves below middle C. This is 20 times lower than would be expected for a mammal of their size. In fact, it is more in tune with what you would expect from an elephant.
Charlton's team discovered the secret: a completely new organ. Located in the koala's throat, the organ Charlton describes for the first time, allows the rumbling bellows. To date, scientists know of no other mammal with such an organ.
The new organ is a second set of vocal folds that look and work very much like the pair in the larynx. They are found, however, at the velum—the junction where the koala's windpipe branches into its nose and mouth.
These velar vocal folds, or VVFs, are three times longer than the folds in the larynx, 15 times wider, 14 times deeper and almost 700 times heavier. Their huge size allows them to produce the extremely deep pitches of the mating bellow, according to Charlton. These pitches range as low as 10 Hertz and the koalas can belt them out with tremendous energy.
Charlton placed suction pumps inside the cadavers of three male koalas. This allowed him to suck air in through their noses, vibrating the VVFs. This produced deep sounds that are remarkably like those of living, bellowing males.
Charlton suggests that the koalas evolved this special organ to help enhance information about a male's breeding quality. The bellows might be an exaggerated signal, given the size ratio of the animal to the sound produced, but they are still honest signals. Bigger males are probably capable of producing deeper, louder bellows in a way that smaller males would not be able to duplicate. This would give females a way to judge a male's quality as a potential mate.
Charlton and his team would like to investigate whether other mammals have developed these same VVFs, but at the moment, it appears to be a koala innovation. “It appears that this remarkable adaptation has evolved independently in the koala specifically to produce their exceptionally low-pitched mating calls,” says Charlton.
"To our knowledge, the only other example of a specialized sound-producing organ in mammals that is independent of the larynx are the phonic lips that toothed whales use to generate echolocation clicks," Charlton says.
- [ Watch the Video: Land-Dwelling Fish ]
Brett Smith for redOrbit.com - Your Universe Online
A leaping, legless, land-loving fish called the Pacific leaping blenny isn’t just one of the odder creatures found on Earth – it’s also emblematic of life’s transition from life in water to life on land.
A new study published in the journal Animal Behaviour has found these strange fish-out-of-water depend on camouflage to escape would-be predators.
"This terrestrial fish spends all of its adult life living on the rocks in the splash zone, hopping around defending its territory, feeding and courting mates. They offer a unique opportunity to discover in a living animal how the transition from water to the land has taken place," said study author Terry Ord, an evolutionary biologist at the University of New South Wales.
The bizarre fish measures between 1.6 and 3.2 inches long when fully grown and leaps using a tail-twisting technique. It lives on land its entire adult life, but has to stay moist in order to breathe through its gills and skin.
To determine the potential effects of camouflage, the study team began by measuring the color of five different populations of the blenny found around the Pacific island of Guam. The colors of the fish were compared to the color of the rocks they lived on.
“They were virtually identical in each case,” Ord said. “The fish's body color is camouflaged to match the rocks, presumably so they aren't obvious to predators.”
Next, the researchers created realistic but fake blennies out of plasticine.
"We put lots of these model blennies on the rocks where the fish live, as well as on an adjacent beach where their body color against the sand made them much more conspicuous to predators," Ord explained. "After several days we collected the models and recorded how often birds, lizards and crabs had attacked them from the marks in the plasticine.”
“We found the models on the sand were attacked far more frequently than those on the rocks,” he added. "This means the fish are uniquely camouflaged to their rocky environments and this helps them avoid being eaten by land predators."
The study team also looked at the body colors of closely related species that either lived in the water or were amphibious like the leaping blenny.
"These species provide an evolutionary snapshot of each stage of the land invasion by fish," Ord said.
The team noted remarkable similarities in color among these species and suggested the ancestors of the Pacific leaping blenny already had a coloration that matched the shoreline before they began spending more of their time out of the water.
Ord and his colleague S. Tonia Hsieh of Temple University have been studying the foraging and mating habits of the Pacific leaping blenny for years. In a 2011 interview with National Geographic, Ord noted these animals are still fish – even though they spend much of their time on land.
"While these fish are very good at living on land ... they are nevertheless very constrained by their evolutionary history," he said.
- [ Watch the Video: Fire Ants Being Smashed by Petri Dish ]
redOrbit Staff & Wire Reports - Your Universe Online
Fire ants are capable of joining together to form a waterproof structure capable of bouncing back to its original shape when stretched or compressed, according to research presented Tuesday at the annual meeting of the American Physical Society's (APS) Division of Fluid Dynamics (DFD).
Researchers from the Georgia Institute of Technology explain that these ants can link their bodies together, forming waterproof rafts that behave much like an active material capable of changing state from a solid to a liquid. The ants can drip, spread and coagulate; and this transition helps them survive rainfall and crashing waves.
In a statement, the APS compares the structure’s behavior to Jell-O and toothpaste, stating that they are all “viscoelastic” materials capable of resisting flow under stress and reverting to their original shape like rubber bands. The fire ant rafts do not behave exactly like solids or liquids, but as a kind of hybrid of the two.
“The linkage structure they form, similar to a truss structure, is elastic and so is able to sustain external forces,” explained lead researcher Zhongyang Liu, an undergraduate student in the laboratory of Georgia Tech mechanical engineer and biologist David Hu. In short, the ants form these rafts by linking their legs and jaws to one-another, creating a structure that is constantly in flux.
“The ants repeatedly form, break, and reform their body-part connections,” the APS added. “Through these rearrangements, the researchers discovered, the raft is able to store energy (and thus acts as an elastic material) and dissipate energy (as a viscous material) to equivalent degrees – a situation that has not been seen in any other active materials, such as bacteria films or liquid crystals.”
Furthermore, Liu’s team found that rafts constructed out of deceased ants do not possess this quality. Rather, they behave more like solid viscoelastic materials. Liu called this the team’s “most important discovery.” He added that the swarm intelligence demonstrated by the ants to complete this task could be adapted to robotics research, and that the rafts they form could help spur new discoveries in the field of materials science.
Along with Liu and Hu, other Georgia Tech researchers credited as authors on the study include John Hyatt, Nathan Mlot, Michael Gerov and assistant professor Alberto Fernandez-Nieves.
Their presentation entitled “Ants cushion applied stress by active rearrangements” took place Tuesday afternoon at the conference, which is being held this year at the David L. Lawrence Convention Center in Pittsburgh, Pennsylvania.
- Peter Suciu for redOrbit.com - Your Universe Online
3D printing has already revolutionized the world of design, and it has begun to make its way into the production of actual products.
Now researchers have found a way to extract DNA from ancient fossilized bones and use 3D printing technology to create accurate copies. While it won’t be able to bring back living dinosaurs like those seen in “Jurassic Park,” this technique could soon make it a lot easier to replicate rare fossils and, more importantly, do so without damaging the rare and delicate originals.
A team of German researchers have been studying the feasibility of utilizing data from computed tomography (CT) scans along with 3D printers to create the copies of the fossils.
This is noteworthy because most dinosaur fossils are stored in plaster casts or jackets, and gathering information about these specimens requires their removal from storage. Traditionally to make a copy required that all sediment surrounding the fossil needed to be cleaned, and during this process, material could be lost, while there was also the risk of damage to the fossil itself.
The CT scans allow for the fossils to be copied without ever being removed from the plaster jackets.
“The most important benefit of this method is that it is non-destructive, and the risk of harming the fossil is minimal,” said study author Ahi Sema Issever, MD, from the Department of Radiology at Charité Campus Mitte in Berlin, via a statement. “Also, it is not as time-consuming as conventional preparation.”
This study is also notable in that the researchers are also trying to identify fossils that were damaged during the Second World War, and the CT scans helped solve what has long been a mystery – namely what exactly is in many of the plaster jackets.
A group of plaster jackets was discovered beneath piles of rubble in the ruins of Berlin’s Museum für Naturkunde after the war. While the museum was restored following the damage it received during a wartime air raid, some of the fossil specimens have been difficult to identify.
The CT scanning technology has helped solve the mystery, as it has allowed for a detailed rendering that can be fed into a 3D printer, from which an accurate reconstruction of the fossil can be made.
Researchers were able to perform a CT scan on an unidentified fossil, utilizing a process that involved a 320-slice multi-detector system, which provided a clear view of the bone. From this the researchers were even able to trace the fossil’s origin to the Halberstadt excavation, which was a major dig from 1910 to 1927. Numerous dinosaur fossils were found in a clay pit south of the German city of Halberstadt.
“The digital dataset and, ultimately, reproductions of the 3-D print may easily be shared, and other research facilities could thus gain valuable informational access to rare fossils, which otherwise would have been restricted,” Dr. Issever added. “Just like Gutenberg's printing press opened the world of books to the public, digital datasets and 3-D prints of fossils may now be distributed more broadly, while protecting the original intact fossil.”
While it won’t allow those dinosaurs to be seen in the flesh, this technology could potentially create a global interchange of unique fossils between various institutions including museums and schools where endless exact copies could be produced and displayed.
The results of the study were published in the journal Radiology.