The world’s oldest flamingo flew to that great big aviary in the sky last week. Greater, as it was known, was the most famous flamingo in Australia’s Adelaide Zoo when it was put to sleep at age 83.
The bird was suffering from severe arthritis and was nearly blind; zookeepers decided that putting Greater down was the most humane thing they could do.
Most of us are impressed when our pets live merely into the low double digits. But there are creatures out there that put in some serious time on Earth, especially compared with us humans. Some sea sponges last more than 1,500 years. (See also “How Old Is That Lion? A Guide to Aging Animals.”)
Herewith, six of the most famously long-lived individual animals:
The last thing a barn swallow probably expects as it’s flying low over a lake is to be met with a mouthful of needle-sharp teeth emerging from the water. And if the bird happens to be flying over a certain lake in South Africa, that may well be the last thing it sees.
A recent study has caught what researchers say are the first scientific observations of a fish launching itself out of the water to catch birds in midair.
“There are more than 14,000 freshwater fish species in the world,” wrote Nico Smit, director of the unit for environmental sciences and management at North-West University in Potchefstroom, South Africa, in an email. “[But] of those, only about five species are known to prey on birds, so I definitely don’t think it is a widespread behavior.”
For the most part, when fish feed on birds, it’s a meal of opportunity, Smit noted. Either the birds have accidentally fallen into the water, or waterfowl like ducks just happen to paddle over the wrong stretch of a lake or river.
But during a 15 day survey in February 2010, Smit and colleagues saw African tigerfish—which populate a storage lake for the Schroda Dam in South Africa—snatching barn swallows out of the air, they report in a study published online last month in the Journal of Fish Biology.
Unlike other instances of fish eating birds, barn swallows actually seem to be a fairly regular part of a tigerfish’s summer diet when the swallows are available, Smit said. “[The fish] have been incredibly well adapted to hunt the flying birds as part of their daily routine.”
Video taken by study co-author Francois Jacobs, also of North-West University in South Africa, is just getting major media attention now.
Beginning around twilight, tigerfish near the Schroda Dam patrol deep open water near well-vegetated areas. They exhibit a less active lifestyle during the day, which they spend in the deeper, more sheltered water, the study authors write.
But during the 2011 survey, researchers noticed that five of the tigerfish (Hydrocynus vittatus) they had tagged exhibited increases in their midmorning activities.
Smit and colleagues did not observe any of their tagged fish leaping for barn swallows (Hirundo rustica), but they did observe other tigerfish catching the birds in midair.
The fish would either follow the birds in a surface pursuit before leaping up to try and catch them, or the tigerfish would track the swallows from deeper in the water and launch into the air to ambush them.
Smit marvels at the skill it takes for these fish to capture birds on the wing. Tigerfish have to spot a fast-flying swallow from the water, exceed the bird’s speed, compensate for refraction—or the fact that the angle of light changes when it goes from air to water—and then leap out of the water to grab the bird, he explained.
Over the course of their study, researchers saw up to 20 successful attempts on flying barn swallows by tigerfish in one day.
“During the 15-day survey as many as 300 [barn swallows] were preyed upon by the local [tigerfish] population, indicating that this feeding behavior is not occasional,” the study authors write.
They speculate that the scarcity of other food in the Schroda Dam lake, like other species of fish, have driven these tigerfish to attempt loftier prey.
“I think this research also illustrates that we still actually know incredibly little about the behavior of freshwater fish in Africa,” Smit said. “The fact that this amazing behavior has escaped documentation for so long surely means that a lot more needs to be discovered.”
Dogs don’t need a compass: Your best friend can sense Earth’s magnetic field, say researchers who report that dogs preferentially align themselves facing north or south to do their business.
Dogs are well known for their excellent sense of smell and their keen sense of hearing. The team, led by zoologist Hynek Burda of Germany’s University of Duisburg-Essen, reports in the journal Frontiers in Zoology that our furry friends prefer to relieve themselves or do their territorial marking while facing north or south. That implies they are sensing the Earth’s magnetic field.
“They do so, however, only when the magnetic field is calm—something [that] we ourselves are not able to recognize unless we look on the actual daily magnetograms released by geomagnetic observatories,” says Burda.
The new findings have important implications in our understanding of magnetoreception in mammals. Previous work by Burda and his team showed that cows, deer, and foxes are sensitive to Earth’s magnetic field, but this is the first study showing a mammal not only being able to sense it, but also to exhibit a specific behavior in response to natural magnetic field variations.
The findings are also appealing for another reasons, Burda adds: “To many dog owners who know about the good navigation abilities of their protégés, the findings might not come as a surprise, but rather as an explanation for the ‘supernatural’ abilities—although it is not clear to the researchers what the dogs might use their magnetic sense for.” (The researchers intend to set up a university website for dog owners who wish to test their own pet’s abilities; the site is expected to be up by January 6.)
Doing Their Business
In the two-year study, the researchers analyzed the body orientation of 70 dogs from different breeds as the dogs relieved themselves. At first look, their analyses showed no clear pattern of dogs preferring any particular orientation to do their business.
However, when the researchers took into account the naturally occurring variations of Earth’s magnetic field and factors like the time of the day, the position of the sun, and wind direction, the doggy sixth sense was revealed.
“The emerging picture of the analysis of the categorized data is as clear as [it is] astounding: Dogs prefer alignment along the magnetic north-south axis, but only in periods of calm magnetic field conditions,” said Burda.
In other words, under stable magnetic conditions the dogs would always poop and pee while facing either north or south. This provides convincing evidence that dogs can sense magnetic fields and are sensitive to even small magnetic-field variations, say the researchers.
New Answers, More Questions
Future research will focus on two basic questions: What are dogs are doing with this ability, and how are they doing it? It also raises questions about how magnetic storms affect an animal’s behavior.
The results may provide an explanation as to why previous research on magnetoreception had mixed results. Calm magnetic-field conditions occurred only 30 percent of the time during the study. So future research will need to correct for these variations in order to obtain reproducible results. This also means that earlier researchers might consider reanalyzing their data to take into account variations in the magnetic field.
Credits: Weird & Wild
Wild cats are charismatic creatures, so you’d think we’d know them all pretty well by now. Just how little we understand—at least in some cases—is reflected in the identification of a new species of cat known as a tigrina in northeastern Brazil.
Scientists have discovered that two populations of tigrina previously thought to be one species do not, in fact, interbreed and thus are distinct, according to results published today in Current Biology.
“So much is still unknown about the natural world, even in groups that are supposed to be well-characterized, such as cats,” says the study’s lead author, Eduardo Eizirik of Pontifícia Universidade Católica do Rio Grande do Sul in Brazil.
“In fact, there are many basic aspects that we still don’t know about wild cats, from their precise geographic distribution and their diets.”
Eizirik’s results have implications for conservation efforts—particularly laws about poaching and the designation of national parkland. Such measures are often focused on individual species.
Recognizing the northeastern tigrina as distinct means that biologists will have to assess its conservation status and determine what steps need to be taken so that both species of tigrina can be adequately protected. (See “Rare Cat Captured in Camera Trap.”)
Eizirik and colleagues weren’t looking to discover a new species. Instead, they were looking to understand the evolutionary history of what were thought to be three species of cat from the genus Leopardus:
The Pampas cat (Leopardus colocolo) looks like a large, heavy-set, long-haired house cat. It lives in the grasslands and scrublands of South America, from southern Argentina and Chile up through Peru and Ecuador along the western third of the continent.
Geoffroy’s cat (Leopardus geoffroyi) is roughly the same size as the Pampas cat, with a brownish-yellow or gray coat, black spots on its trunk, and dark bands across its tail and limbs. Like the Pampas cat, Geoffroy’s cat likes scrublands and lives throughout Argentina.
The tigrina (Leopardus tigrinus), also known as the oncilla or little spotted cat, lives throughout much of Central and South America. With a yellow-brown coat and black rosettes, the tigrina looks like a house cat-sized leopard. Scientists had previously identified four sub-populations of tigrina, including the southern tigrina, which lives primarily in Brazil’s mountainous forests, and the northeastern tigrina, which lives in savannahs and grasslands. The coat of the northeastern tigrina is slightly lighter, and the rosettes are sightly smaller, than those of its southern relative. (Learn about National Geographic’s big cats initiative.)
Eizirik and colleagues obtained DNA samples from a total of 216 different Leopardus cats across their ranges. Analysis of the DNA sequences found in the mitochondria, the cell’s power plant, revealed ancient interbreeding between the Pampas cat and the northeastern tigrina.
Since an individual only inherits mitochondrial DNA from its mother, researchers could peer into the ancient history of these two felines, and found that they mated together frequently before the two cats split into separate species.
Although the Geoffroy’s cat and the southern tigrina divided into separate species over a million years ago, they began to mate together in the more recent past in the areas of southern Brazil and Bolivia where their habitats overlap. While the two cats interbreed regularly at this contact zone, the mating doesn’t extend to farther areas and the two species remain distinct.
When Eizirik and colleagues analyzed the genetics of the two different tigrina populations, however, they were surprised to learn that genes did not appear to be moving between the northeastern and southern tigrinas. (See “Pictures: 7 Cat Species Found in 1 Forest—A Record.”)
“This observation implies that these tigrina populations are not interbreeding, which led us to recognize them as distinct species,” Eizirik says. The researchers have suggested that the northeastern tigrina retain its current name of L. tigrinus, while dubbing the southern tigrina L. guttulus.
“Very little was—and still is—known about this species,” says Eizirik. “There have been some initial studies on its diet, but still most of its basic biology remains poorly known, including density, habitat use, and population trends.”
Forget circumnavigating the globe in 80 days—an albatross can do it in a mere 46!
These world travelers are among the largest flying birds, weighing up to 25 pounds (11 kilograms), and with a wingspan of 11 feet (3 meters). But hefting such huge bodies off the ground takes a lot of energy. If albatrosses flew simply by flapping their wings, they would lose about half their body mass fueling that kind of flight.
So how do these kings of the sky complete such long journeys so quickly? It turns out they glide in a specific flight pattern that allows them to harness wind energy, gliding right above the sea’s surface to stay aloft, according to a study published in the Journal of Experimental Biology.
Coasting Through Life
A team of scientists from the Technische Universitat Munchen in Munich, Germany, used aerospace engineering to reveal the birds’ unique flight patterns—a physical feat that has puzzled academics for years. By attaching GPS trackers to 20 wandering albatrosses (Diomedea exulans) in the wild, the researchers were able to study data from 16 of the birds as they left and returned to the Kerguelen Archipelago (map) in the Indian Ocean.
Albatrosses yo-yo up and down in the sky, taking advantage of momentum generated on their downhill glides in order to climb back up against the wind. These constant up and down changes in altitude keep the birds aloft without requiring much effort. In fact, the propulsive force generated by such undulations is about ten times greater than anything the albatross could create by simply flapping its wings.
Working Harder, Not Smarter
But it’s a trick the rest of the animal kingdom doesn’t often use. For example, hummingbirds weigh about 0.07 ounces (2.2 grams)—98 percent less than an albatross—and yet their wings have to beat about 70 times per second to keep their little bodies aloft. An albatross can go hours without flapping. Because of this frantic motion, hummingbirds have to eat up to three times their body weight every day.
Even humans struggle with energy efficiency. “An elite cyclist at 60 percent of his maximum aerobic rate can only support 15 to 30 percent of his energy needs with consumed sugars,” according to a LiveScience article. That means we have to refuel more often than the albatross, which can travel greater distances without working as hard.
While it took Jules Verne’s characters just over two and a half months to circumnavigate the globe, an albatross can do it in about half the time. Phileas Fogg and his trusty sidekick Passepartout just can’t compete with these fantastic flyers!
Although we can’t always perceive them, vibrations provide a critical way of communicating for many animal species.
Scientists think vibrational communication is an ancient sensory mode—one that is still widely used throughout the animal kingdom. Animals from tiny insects to jumbo-size elephants talk to each other using vibrations for many different purposes, from mating and hunting to solving territorial disputes and warning predators away.
Read on to discover some of the animals that use good vibes to communicate.
1. Caribbean White-Lipped Frog
Like many frogs, male Caribbean white-lipped frogs sing to attract mates. But their songs contain more than just pleasing sounds.
When they call, the frogs sit with their rear ends buried in the mud and their head and front legs just above the ground. With each chirp they make, their vocal sacs expand and contract, hitting the ground and producing an accompanying vibration.
The thumps can be felt 10 to 20 feet (3 to 6 meters) away. Since singing males space themselves apart by 3 to 7 feet (1 to 2 meters), each can feel the calls of its nearest neighbors. Scientists think males might use this vibrational information to maintain the distance between them or time their calls so they don’t overlap. (See “‘Deaf’ Frog Hears By Using Its Mouth As An Echo Chamber.”)
2. Jumping Spiders
Male jumping spiders go to great lengths to attract females, putting on colorful and elaborate displays that also include a vibrational component.
Male spiders generate their vibes by rubbing parts of their bodies together, drumming body parts against the ground, and vibrating special organs. These vibrations not only make the female more likely to mate, they also decrease the chances that she will eat her suitor.
There are some jumping spiders that take advantage of other spiders’ vibrational sensitivities to prey on them. These jumping spiders invade a potential meal’s web and mimic the vibrations of an insect struggling to escape. When the spider approaches to investigate, the sneaky trickster makes a meal of it. Other spider species imitate the vibrations of a courting male to attract and then prey on interested females. (Watch video of jumping spiders attacking insects.)
The low-frequency calls of elephants actually travel farther through the ground than they do through the air—perfect for communicating over long distances. (See “Elephants ‘Hear’ Warnings With Their Feet, Study Confirms.”)
Elephants detect these seismic waves with the skin of their feet and trunk. Researchers have observed elephants in the wild leaning forward and putting more weight on their front legs, presumably to increase ground contact and the sensitivity of their feet.
By using vibrations, highly social elephants can tell each other about danger from miles away. (See “Elephants Communicate in Sophisticated Sign Language, Researchers Say.”)
4. Mole Rats
Mole rats are a group of rodents that live in underground burrows. Under the ground, there is not much light for visual signals, and sound doesn’t travel very far. So several species of mole rats have developed other ways to communicate—like head-banging.
The Middle East blind mole rat knocks its head against the walls of its tunnels to signal to its neighbors. Demon mole rats also head-bang to talk to each other, and the pattern of their banging might even be specific enough to communicate an individual’s identity to its neighbors.
African termites build giant mounds in which they live and grow fungus for food. If a mound is threatened by a predator such as an aardvark, chains of drumming termite soldiers head-bang an alarm.
To alert the entire colony of an impending attack, termites will bang their heads on the ground about 11 times a second. One termite’s head-drumming travels only about 15 inches (38 centimeters), but any termite close enough to hear the alarm responds by drumming its head too. In this way, the alarm spreads like a chain reaction through the colony. (Related: “Africa’s Mysterious ‘Fairy Circles’ Explained.”)
6. Kangaroo Rats
Like a desert version of Disney’s Thumper, banner-tailed kangaroo rats use foot-drumming to communicate in a number of situations, including when they encounter snakes.
The foot-drumming may be a form of parental care, warning vulnerable offspring that a dangerous predator is near. It could also convey to the snake that the kangaroo rat has spotted it and the reptile should probably look for easier prey elsewhere.
Treehoppers are tiny insects that cling to plant stems and often live in family groups. They communicate with each other by vibrating the stem they’re sitting on. Although none of their signals are perceptible to humans without the aid of specialized instruments, treehoppers produce a surprising variety of vibrational signals.
Young treehoppers will signal to the group when they’ve found a new stem to eat, or to send out an alarm if a predator approaches. Adult males also vibrate to attract mates. Interested females respond to these vibrational courtship songs by vibrating back.
Credits: Weird & Wild
Harvard scientists have discovered a chemical in bear bile that may slow the development of type 1 diabetes, according to a study in the journal Science Translational Medicine.
The bitter, yellow-green liquid drained from the innards of a bear is a common ingredient in many traditional Chinese medicines. Stored in the gallbladder of a black bear, bile is thought to cure everything from liver disease to epilepsy. It’s so precious that it costs about half as much as gold, said Gokhan Hotamisligil, a geneticist at Harvard University School of Public Health and a co-author of the study.
“The gallbladder of the bear was one of the most valuable voodoo medicines that people used, especially in China,” Hotamisligil said. “It almost made the black bear extinct [in China]. It started illicit harvesting and trafficking of bear gallbladder.” (See “Endangered Moon Bears Harvested for Bile in Vietnam.”)
The remedy has been prescribed for centuries—the first known medicinal reference to bear bile was recorded in 659 A.D.—and it’s still used today. “Some 10,000 bears are farmed in China to procure their bile for traditional Chinese medicine,” according to a 2012 letter published in the journal Nature.
In the past, it’s likely people got their bear bile after hunting the animals. But in the 1980s the People’s Republic of China invented a harvesting method that drains the bile while the animal is still alive. “An un-sterile … catheter was inserted through the external fistula directly into the gall bladders of each bear to drain the fluid daily either by gravity into a tray or by suction with an un-sterile syringe,” according to a 2009 study in the Journal of Ethnobiology and Ethnomedicine.
Luckily, no bears were harmed in the making of Hotamisligil’s study. You can get bear bile-like chemicals from other types of animals like oxen. Hotamisligil purchases it from a company that harvests it out of livestock. He’s using the unappetizing stuff in an attempt to resolve what he calls “the biggest global threat to health.”
“We believe in 25 years there will be in the range of half a billion people in the world with diabetes,” he said. “The magnitude of the problem is intense. We’re going to face a huge problem if we don’t deal with this.”
There are two types of diabetes, type 1 and type 2. Type 1 diabetes happens when the immune system attacks and maims beta cells, which help produce insulin. Insulin regulates your blood sugar, which ebbs and flows depending on what you eat. Without it, your blood sugar can spike or drop so quickly that you go into a coma. In people with type 2 diabetes, the pancreas may produce insulin, but their bodies don’t respond to the hormone.
Type 1 diabetes is mostly a problem for children, who usually develop the disease in their early years up until young adulthood. Bile is rich in a chemical called TUDCA, which stands for tauroursodeoxycholic acid. The substance appears to shield the beta cells in mice models from immune system attack.
“If we give animals [TUDCA before they] become diabetic, they never become diabetic,” Hotamisligil said.
Their beta cells do not succumb to attacks from the body’s immune system, and they continue to produce insulin, he added. “There is a very dramatic protection.”
Waiting for a Disease
Scientists have the ability to identify children who are at risk for developing type 1 diabetes, but right now, there’s nothing they can do with the information but wait for symptoms to develop. If bear bile is effective in humans, it could potentially slow or even halt the progression of this life-changing illness.
In higher concentrations, the bile might even help people at risk for type 2 diabetes, Hotamisligil said.
“The research is important because it shows the use of a very safe drug that could be used to either prevent or slow the onset of the disease,” said Rudy Leibel, a molecular geneticist at the Columbia University Medical Center in New York City who was not involved in the research.
The Harvard scientist has given himself a tight timeline. His team tried hundreds of thousands of molecules before settling on bear bile in 2004. Now Hotamisligil wants to move to human trials in no more than a year and a half. Because bear bile is already FDA-approved for clinical use, Hotamisligil’s goal might not be out of reach.
“The funding for biomedical research has been cut, [but] we will find resources one way or another and start a trial,” Hotamisligil said. “We’ll initiate this in humans.”