Elephants dilate their nostrils to create more space in their trunks, allowing them to store up to 5.5 liters (1.45 gallons) of water, according to their new study.
They can also suck up three liters (0.79 gallons) per second—a speed 30 times faster than a human sneeze (150 meters per second/330 mph), the researchers found.
The researchers wanted to better understand the physics of how elephants use their trunks to move and manipulate air, water, food, and other objects. They also wanted to learn if the mechanics could inspire the creation of more efficient robots that use air motion to hold and move things.
Photo by David Clode on Unsplash
While octopuses use jets of water to propel themselves and archer fish shoot water above the surface to catch insects, elephants are the only animals able to use suction both on land and underwater.
"An elephant eats about 400 pounds of food a day, but very little is known about how they use their trunks to pick up lightweight food and water for 18 hours, every day," says lead author Andrew Schulz, a mechanical engineering PhD student at the Georgia Institute of Technology. "It turns out their trunks act like suitcases, capable of expanding when necessary."
Sucking up tortilla chips without breaking them
Schulz and his colleagues worked with veterinarians at Zoo Atlanta, studying elephants as they ate various foods. For large rutabaga cubes, for example, the animal grabbed and collected them. It sucked up smaller cubes and made a loud vacuuming sound, like the sound of a person slurping noodles, before transferring the vegetables to its mouth.
To learn more about suction, the researchers gave elephants a tortilla chip and measured the applied force. Sometimes the animal pressed down on the chip and breathed in, suspending the chip on the tip of its trunk without breaking it, similar to a person inhaling a piece of paper onto their mouth. Other times the elephant applied suction from a distance, drawing the chip to the edge of its trunk.
Elephants inhale at speeds comparable to Japan's 300 mph bullet trains.
"An elephant uses its trunk like a Swiss Army knife," says David Hu, Schulz's advisor and a professor in Georgia Tech's School of Mechanical Engineering. "It can detect scents and grab things. Other times it blows objects away like a leaf blower or sniffs them in like a vacuum."
By watching elephants inhale liquid from an aquarium, the team was able to time the durations and measure volume. In just 1.5 seconds, the trunk sucked up 3.7 liters (just shy of 1 gallon), the equivalent of 20 toilets flushing simultaneously.
Soft robots and elephant conservation
The researchers used an ultrasonic probe to take trunk wall measurements and see how the trunk's inner muscles work. By contracting those muscles, the animal dilates its nostrils up to 30%. This decreases the thickness of the walls and expands nasal volume by 64%.
"At first it didn't make sense: an elephant's nasal passage is relatively small and it was inhaling more water than it should," Schulz says. "It wasn't until we saw the ultrasonographic images and watched the nostrils expand that we realized how they did it. Air makes the walls open, and the animal can store far more water than we originally estimated."
Based on the pressures applied, Schulz and the team suggest that elephants inhale at speeds comparable to Japan's 300-mph bullet trains.
Schulz says these unique characteristics have applications in soft robotics and conservation efforts.
"By investigating the mechanics and physics behind trunk muscle movements, we can apply the physical mechanisms—combinations of suction and grasping—to find new ways to build robots," Schulz says.
"In the meantime, the African elephant is now listed as endangered because of poaching and loss of habitat. Its trunk makes it a unique species to study. By learning more about them, we can learn how to better conserve elephants in the wild."
The paper appears in the Journal of the Royal Society Interface. The US Army Research Laboratory and the US Army Research Office 294 Mechanical Sciences Division, Complex Dynamics and Systems Program, funded the work. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the view of the sponsoring agency.
Source: Georgia Tech
Original Study DOI: 10.1098/rsif.2021.0215
Reprinted with permission of Futurity. Read the original article.
Adam's (or Rama's) Bridge between India (left) and Sri Lanka, as captured from the Space Shuttle Endeavour in 1994.Credit: NASA, public domain.
The string of limestone islands slung between India and Sri Lanka was once a bridge built by Rama to retrieve his wife held hostage on the island; or, it was crossed by Adam on his flight from Eden — depending on which epic you prefer.
To the north, the shallows of the Palk Bay eventually become the Bay of Bengal. To the south, the Gulf of Mannar is the antechamber of the Indian Ocean. Formerly fertile fishing grounds, both bodies of water are now hotbeds of a relatively recent kind of marine-based misdeed: sea cucumber crime.
Crimes against sea cucumbers
As this map indicates, the number of criminal incidents in both India and Sri Lanka involving sea cucumbers has increased from no more than eight in 2015 to no less than 58 in 2020. In other words: it's a crime spree!
While most cases are concentrated on either side of Rama's (or Adam's) Bridge, the most recent wave has also touched Lakshadweep, the cluster of small islands that constitutes one of the union territories of India to the west of its mainland (and on the left on this map).
Like their terrestrial namesakes, sea cucumbers are tubular creatures. But that's where the comparison ends. Sea cucumbers are animal, not vegetal. Some grow up to six feet long. And while you can get a land cucumber for under a dollar at the supermarket, a kilo of sea cucumbers will easily set you back hundreds, if not thousands, of dollars.
Also known as sea slugs or sea leeches, sea cucumbers are a family of about 1,450 different species worldwide and are cousins to sea stars, sand dollars, and other echinoderms. Eyeless and limbless, they do have a mouth and an anus, and these they put to good use: by recycling waste into nutrients, they excrete key ingredients (to the tune of five Eiffel Towers' worth per reef per year) for coral reefs and help slow the acidification of the oceans.
For centuries, sea cucumbers have also been a sought-after delicacy and used as a dubious medicinal ingredient in China and Southeast Asia. Sea cucumbers are eaten dried, fried, pickled, or raw; as an accompaniment to Chinese cabbage or shiitake mushrooms; spiced and mixed with meat or other seafood; and used in soups, stews, and stir-fries. In traditional medicine, they're believed to help against arthritis, impotence, cancer, and frequent urination. They're also used in oils, creams, tinctures, and cosmetics.
Eye-wateringly expensive: the dragon-like Japanese sea cucumber (Stichopus japonica).Credit: harum.koh and licensed under cc by-sa 2.0
An exploding sea cucumber market
In the past, sea cucumbers were the preserve of the very rich, who presented each other with ornate boxes of the luxury product in dried form. However, the burgeoning of China's middle classes since the 1980s has led to an exponential increase in demand, with ripple effects all over the world.
In the 1980s, a kilo of sea cucumbers (or bêche-de-mer or trepang, if you're into the whole culinary nomenclature thing) would set you back about $70. Now, it's closer to $300 and up to $3,500 for the rarer species — for example the Japanese sea cucumber, whose spikes make it look like a dragon.
Since then, global populations of the most expensive species have dropped by as much as 60 percent. As the net gets emptier, it is cast wider. From 1996 to 2011, the number of countries exporting sea cucumbers rose from 35 to 83. But the sea cucumber populations simply can't handle that much strain. In the sea cucumber fields off Yucatan, for example, yields dropped by 95 percent from 2012 to 2014. And between 2000 and 2016, standing stocks of various sea cucumber species near the Egyptian Red Sea port of Abu Ghosoun fell by 87 percent due to overfishing.
The sea cucumber crime wave has increased, both in numbers and area, now also reaching Lakshadweep (in the west).Credit: Phelps Bondaroff/Katapult Magazin, reproduced with kind permission.
The seafood mafia
As sea cucumbers get rarer, they get more valuable, which in turn encourages more illegal fishing. The average global price went up by 17 percent from 2011 to 2016. That drives the competition for the remaining specimens to dangerous heights — or rather, depths. According to the Central Marine Fisheries Research Institute in Kochi (Kerala, India), the species dwelling in shallow waters have been depleted to such an extent that divers are now targeting those in deeper waters. Without proper gear and training, that is potentially deadly. And not just in Indian waters. Back in Yucatan, at least 40 divers have lost their lives harvesting sea cucumbers, most from decompression sickness.
The situation in the waters off India and Sri Lanka is complicated by both countries' different legal approaches to sea cucumber scarcity. In 2001, India banned the trade and export of sea cucumbers. As per Schedule 1 of the Wildlife Protection Act, they now enjoy the same level of protection as India's lions and tigers.
Meanwhile in Sri Lanka, which has seen its sea cucumber grounds to the south and east collapse and shrink to just the northern side of the island, fishing for sea cucumbers remains legal but is subject to licenses to try to prevent overexploitation.
Having a legal market for sea cucumbers right next to an illegal one offers the "seafood mafia" two lucrative courses of action. First, harvest the dwindling stock of sea cucumbers right from under the noses of the Sri Lankan divers and fishermen. Second, smuggle the illegally caught ones from India into Sri Lanka, where they can be sold as if they were caught legally — a form of "seafood laundering," if you will.
Braised shark"s fin, sea cucumber and shiitake mushroomCredit: avixyz and licensed under cc by-sa 2.0
As the map shows, both countries are stepping up their efforts against sea cucumber crime. Moreover, in 2020, Lakshadweep inaugurated the Dr. K.K. Mohammed Koya Sea Cucumber Conservation Reserve. Centered on the Cheripanyi Reef, an uninhabited atoll, the 239-km2 (149-mi2) reserve is the first of its kind in the world.
The union territory also set up a Sea Cucumber Protection Task Force, which has seized considerable amounts of illegally harvested sea cucumbers, including a haul of 1,716 creatures weighing a total of 882 kg (almost a ton), which could have netted as much as 42.6 million rupees ($854,000) on the market.
Save the sea cucumbers!
While conservation efforts are commendable, the increasing scarcity and rising prices of sea cucumbers will continue to prove irresistible to the seafood mafia. There is some hope in aquaculture, with projects underway in China and elsewhere. However, only a small share of sea cucumber larvae make it into adulthood, a process that can last up to six years.
Sea cucumbers recently also have appeared on the radar of multinational pharmaceutical companies. It may yet turn out that some of their reputed medicinal qualities are more than just folk tales, and some chemicals they contain could help treat cancer and joint pain. It remains to be seen whether this additional source of attention will be a lifeline for the sea cucumbers or the kiss of death.
The world's first sea cucumber reserve in Lakshadweep, off India.Credit: Government of India, Union Territory of Lakshadweep, Department of Environment & Forest.
For more great maps, and to improve your German, check out Katapult Magazin (partially available in English).
Original data for the Katapult map from a paper by Dr. Teale Phelps Bondaroff, titled Sea cucumber crime in India and Sri Lanka during the period 2015–2020.
Strange Maps #1086
Got a strange map? Let me know at strangemaps@gmail.com.
Vanishingly rare, but it exists: a patch of Minnesota forest untouched by the logger's axe.Credit: Dan Alosso on Substack and licensed under CC-BY-SA
The trees here tower a hundred feet above the forest floor — a ceiling as high as in prehistory and vanishingly rare today. That's because no logger's axe has ever touched these woods.
Pillars of the green cathedral
As you walk among the giant pillars of this green cathedral, you might think you're among the redwood trees of California. But those are 1,500 miles (2,500 km) away. No, these are the red and white pines of the "Lost Forty" in Minnesota. This is the largest single surviving patch of old-growth forest in the state and a fair stretch beyond. And it's all thanks to a surveying error.
Despite its name, the Lost Forty Scientific and Natural Area (SNA) is actually 144 acres (0.58 km2) in total. Still, it's an easily overlooked part of the Chippewa National Forest, which sprawls across 666,000 acres (2,700 km2) of north-central Minnesota. And that – being easily overlooked – is kind of this area's superpower.
In the 1820s, when European-Americans arrived in what is now Minnesota, they found about 20 million acres (80,000 km2) of prairie and 30 million acres (120,000 km2) of forest. Two centuries on, both ecosystems largely have been depleted. Fewer than 100,000 acres (400 km2) of natural prairie remain, and fewer than 18 million acres (73,000 km2) of forest.
And today's woods are different. They're not just younger; the original pine stands have been harvested and largely replaced with aspen and birch.
Can a place really be "lost" if it has a sign pointing toward it? Credit: Tony Webster via Flickr and licensed under CC BY-SA 2.0
To the moon and back
White pine especially was in heavy demand during the lumbering boom that had Minnesota in its grip by the 1840s — a boom driven by an insatiable demand for building materials and supercharged by the steam that powered the saws and the rails that transported the goods to market.
The two decades flanking the turn of the 20th century were the golden age of lumbering in Minnesota. At any given time, 20,000 lumberjacks were at work in the woods, a further 20,000 in the sawmills, and another 20,000 in other lumber-related industries.
Production peaked in the year 1900, with over 2.3 billion board-feet (5.4 million m3) of lumber harvested from the state's forests. That was enough to build 600,000 two-story houses or a boardwalk nine feet (2.7 m) wide, circling Earth along the equator. From then on, yields declined, albeit slightly at first. By 1910, however, the first lumber operations started packing up and moving on to the Pacific Northwest and elsewhere.
Minnesota's era of Big Timber symbolically came to an end with the closure of the Virginia and Rainy Lake Lumber Company in 1929. At that time, a century's worth of lumbering in Minnesota had produced 68 billion board-feet (160 million m3) of pine — enough to fill a line of boxcars all the way to the moon and halfway back again.
Now spool back a few decades. It's 1882, and the Public Land Survey is measuring, mapping, and quantifying the wilderness of northern Minnesota — and its as yet unharvested north woods. Setting out from the small settlement of Grand Rapids, Josias Redgate King leads a three-man survey team 40 miles north, into the backwoods.
Mapping error becomes cartographic fact
Their job, specifically, is to chart the area between Moose and Coddington Lakes. And they mess up. Perhaps it's the lousy November weather, the desolate swampy terrain, or both. But they make a serious mistake: their survey stretches Coddington Lake half a mile further northwest than it actually exists. As happens surprisingly often with mapping mistakes, the error becomes cartographic fact, undisputed for decades.
The area is marked on all maps as being under water and is therefore excluded from the considerations of logging companies. Only in 1960 is the area re-surveyed and the error corrected. But by then, as we have seen, Big Timber has moved on from the Gopher State.
Map of the "Lost Forty" SNA (top right). Bordering it on the south is the Chippewa National Forest Unique Biological Area. Credit: Minnesota Department of Natural Resources
Incidentally, Josias R. King was more than the mismapper of Coddington Lake. He has another, and rather better, claim to fame. When the Civil War broke out, Minnesota was the first state to offer volunteers to fight for the Union. At Fort Snelling, Mr. King rushed to the front of a line of men waiting to sign up.
So it was said, with some justification, that he was the first volunteer for the Union in all of the country. During the war, he attained the rank of lieutenant colonel. After, he returned to his civilian job, surveying. Because of his credentials as the Union's first volunteer, he was asked to pose for the face of the bronze soldier on the Civil War monument which was unveiled at St. Paul's Summit Park in 1903.
The loggers' loss is nature's gain
But back to the Lost Forty. The loggers' loss — hence the name — is actually nature's gain. The SNA's crowning glory, literally, is nearly 32 acres of designated old-growth red pine and white pine forest, in two stands, partially extending into the Chippewa National Forest proper. (In fact, much of the mismapped area seems to fall within the Chippewa National Forest Unique Biological Area adjacent to the Lost Forty.) Old-growth forests represent less than 2 percent — and designated old-growth forests less than 0.25 percent — of all of Minnesota's forests.
The oldest pine trees in the Lost Forty are between 300 and 400 years old, close to their maximum natural life span, which is up to 500 years. Similar pines in other parts of the National Forest are harvested at between 80 and 150 years for pulp and lumber. As a result, the pines in the Lost Forty are not only higher than most of the surrounding woods but also bigger with a diameter of between 22 and 48 inches (55 to 122 cm). One of the biggest has a circumference of 115 inches (2.9 m).
With their craggy bark, massive trunks, and dizzying height, these trees look like the ancient beings they are. And they exist in a cluster the size of which is unique for the Midwest. There's nothing lost about these trees; in fact, it's rather the reverse. Perhaps the area should more precisely be called the "Last Forty."
At 52 feet, only half as high as an old-growth white pine: Josias R. King's likeness atop the Soldier's Monument in Summit Park, St. Paul.Credit: Library of Congress
Get a good look at the Lost Forty in this video of the local hiking trail.
Strange Maps #1084
Got a strange map? Let me know at strangemaps@gmail.com.
The coffee beans that keep us going don't grow on the vine in bean form. They grow as coffee "cherries," skin and pulp inside of which resides the precious beans. Before coffee beans can be fermented in water as many are, the cherries pass through a machine that extracts the bean from the skin and pulp. Miraculous as coffee beans are, new research suggests that their typically discarded pulp is even more amazing. It can restore tropical forests.
Researchers from ETH-Zurich and the University of Hawaii have found that this waste from coffee manufacturing is a fantastic growing agent after testing it out on some agriculturally depleted land in Costa Rica.
"The results were dramatic," reports lead author of the study Rebecca Cole. "The area treated with a thick layer of coffee pulp turned into a small forest in only two years while the control plot remained dominated by non-native pasture grasses."
Pulp non-fiction
Coffee pulp arrivesCredit: Rebecca Cole/British Ecological Society
The researchers delivered 30 dump trucks full of coffee pulp to a 35- by 40-meter parcel on Reserva Biológica Sabalito in Costa Rica's Coto Brus county. The land, previously part of a coffee plantation, is in the process of being reforested.
Starting in the 1950s, Costa Rica experienced rapid deforestation followed by coffee-growing and farming that resulted in a 25% loss of its natural forest cover by 2014.
Before spreading out the coffee pulp into a half-meter-thick layer for their test, the researchers measured the nutrients in the soil. They also catalogued the species living nearby, and made note of the size of woody stems present. The amount of forest ground cover was recorded, and drones were sent aloft to capture the amount of canopy cover.
Reforestation in the blink of an eye
(A) Coffee pulp layer; (B) control area after two years; (C) coffee pulp area after two years; (D) overhead view of canopy in control area, above the red line, and the coffee-pulp area, below the red lineCredits: A, B, and C: R. Cole. D: credit R. Zahawi/British Ecological Society
At the end of the two years, the control area had grown forest covering over 20% of its area. In contrast, 80% of the coffee-pulp section was canopied by trees, and these trees were four times the height of those in the control parcel.
The researchers analyzed the nutrients available in the soil and found significantly elevated levels of carbon, nitrogen, and phosphorous, all vital agricultural nutrients. Curiously, potassium, also important for growth, was lower in the coffee-pulp area than in the control section.
The researchers also found that the coffee pulp eliminated invasive pasture grasses that inhibit reforestation. Their removal facilitated the reemergence of tree species whose seeds were introduced by wind or animal dispersal.
A much-needed growth agent
According to Cole, "This case study suggests that agricultural by-products can be used to speed up forest recovery on degraded tropical lands. In situations where processing these by-products incurs a cost to agricultural industries, using them for restoration to meet global reforestation objectives can represent a 'win-win' scenario."
Promising as coffee pulp may be, Cole cautions: "This study was done at only one large site, so more testing is needed to see if this strategy works across a broader range of conditions. The measurements we share are only from the first two years. Longer-term monitoring would show how the coffee pulp affected soil and vegetation over time. Additional testing can also assess whether there are any undesirable effects from the coffee pulp application."
In addition, she notes, the experiment only documents the value of coffee pulp on flat land when delivery of the substance by truck is fairly simple. "We would like," Cole says, "to scale up the study by testing this method across a variety of degraded sites in the landscape."
Just as exciting is the possibility that other such agricultural waste products may be good for reforesting depleted areas. Cole mentions orange husks as a material worthy of investigation.
"We hope," Cole concludes, "our study is a jumping off point for other researchers and industries to take a look at how they might make their production more efficient by creating links to the global restoration movement."
