In Barrow, on the northern coast of Alaska, the sun sets at five o’clock on October 31, and the temperature typically drops into the single digits. Elsewhere in the world people may be composing the polar bear’s epitaph, but in coastal northern Alaska the great white bears are still a part of everyday life.
Native hunters still pursue their millennia-old tradition of hunting polar bears for food and fur.
The bears are drawn to bone piles on land, where locals dump the remains of bowhead whales harvested for subsistence. The Arctic may be ice-free every summer in as few as 30 years, experts predict, and when ice re-forms in winter it will be thinner, and there’ll be much less of it. The polar bears’ ability to survive in a blue-water Arctic is still uncertain, but the outlook is certainly bleak. The natural reaction is to turn to the more immediate—if very much the secondary—conservation challenge for polar bears: people killing them, both for reasons of public safety and for the subsistence harvest. If polar bears face extinction from habitat loss within the century, this thinking goes, doesn’t it make sense to stop all killing of polar bears now? In the Chukchi Sea in western Alaska, biologists find healthy polar bears producing a bumper crop of cubs.
Regehr is fresh ashore from the sea ice himself, where this spring he sedated, examined, and weighed 68 polar bears (including a record-setting 1,390-pounder) before releasing them back into the wild. These add to the growing number of bears studied in the Chukchi Sea since 2008 as part of a multiyear research program to understand the ecology, distribution, and demographics of this population.
Regehr’s data show that polar bears in the Chukchi appear to be as healthy as they were 20 years ago.
While many conservation-minded people in the Lower 48 assume stopping all polar bear harvesting now must be a good idea, shutting down the culturally important subsistence harvest while bears are still abundant—and increasingly visible in some populated areas—would surely backfire, Regehr believes.
What’s more, in the vast, roadless, icy vastness, hunting limits would be nearly impossible to enforce. The approach that will work for both polar bears and polar people, Regehr and others contend, is to use these next few years to lay the groundwork for the challenges ahead. The key is getting hunters, communities, and regional agencies to accept a harvest quota and to participate in its enforcement. The data show that 58 polar bears a year can be sustainably harvested from the Chukchi population today.
FWS and its Native polar bear management partner, the Alaska Nanuuq Commission, are working together to phase in that quota over the next couple of years, building community awareness and mutual trust as they go. Today coastal Alaskan Natives have a cordial and productive relationship with their Chukotkan counterparts. In Russia, all polar bear harvesting has been illegal since 1956, though unofficial reports put the number of bears killed outside the law as high as 100 a year. Alaska, a beautiful place where I thought residents is totally formed by polar bear, now I got there also lives human beings over there.
Less ice=more open water=more photosynthesis= more food for fishes=more fish=more seals=more food for polar bears. I like polar bear, event we don’t have them in our country but I want to help and see them in wildlife.
Polar bears are an icon of the Arctic realm and an indicator of changes taking place there and globally. On Thin IceThe Arctic is warming so fast that by 2050 it may be largely ice free in summer. National Geographic VideoJoin photographer Florian Schulz as he seeks to capture a dramatic image of a polar bear. Velociraptor was featured in the Hollywood blockbuster Jurassic Park, but scientists stress that the movie's dinos bore little resemblance to the real deal. A bizarre gallery of Mesozoic monsters prompts John Updike to ask: What has evolution wrought? A pack of aucasaurs, predators of Argentina's Auca Mahuevo badlands, attacks a group of startled titanosaurs in this artist's depiction. National Geographic explores how we can feed the growing population without overwhelming the planet in our food series. Volunteers risk their lives to vaccinate children in Islamic State-controlled territory in Syria.
January 26, 2009--She's one of the world's best-preserved bodies: Rosalia Lombardo, a two-year-old Sicilian girl who died of pneumonia in 1920. Now an Italian biological anthropologist, Dario Piombino-Mascali of the Institute for Mummies and the Iceman in Bolzano, has discovered the secret formula that preserved Rosalia's body so well. Piombino-Mascali tracked down living relatives of Alfredo Salafia, a Sicilian taxidermist and embalmer who died in 1933. Formalin, now widely used by embalmers, is a mixture of formaldehyde and water that kills bacteria. But it was the zinc salts, according to Melissa Johnson Williams, executive director of the American Society of Embalmers, that were most responsible for Rosalia's amazing state of preservation. Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. I’m always curious to know about the latest big exhibit to come to the Science Museum of Minnesota in St. Last month, Real Pirates: The Untold Story of Whydah from Slave Ship to Pirate Ship opened (through Sept. The artifacts on display range from the Wydah’s bell to dinnerware to real gold coins (yes, real pirate treasure!). Come for the pirates, and stay for the chance to go underwater at the newest Omnitheater film. While at the Science Museum, make sure to enjoy views of the Mississippi River or take a stroll over to Rice Park, surrounded by Landmark Center, the Saint Paul Hotel, and the Ordway Center for the Performing Arts. Museum entry for nonmembers, with the Real Pirates exhibit, runs $22-$30, with Omni too $28-$36 (depending on age, day of the week). Whether you are a seasoned Twin Cities traveler or planning your first trip to Minnesota, this blog will introduce you to many new adventures to add to your itinerary.
On the 25th anniversary of Titanic's rediscovery, high-resolution images from a new expedition are shedding light on the shipwreck. Pictured twisted and broken in late August, railings outline the port rear corner of Titanic's forecastle deck, a raised surface at the bow with crew quarters underneath.The next leg of Expedition Titanic will retrieve hard evidence of corrosiona€”steel test platforms that look something like mini-stepladders. In a first for arthropods, the spiny animal kept its brood tethered to its body as it swam Eartha€™s seas 430 million years ago. Usamos cookies en todos nuestros sitios webs para mejorar tu experiencia durante tu navegacion asi como para obtener datos estadisticos. Las cookies son pequenos archivos de texto que se almacenan en su ordenador cuando usted visita ciertos sitios web. And the odd bear strolling through a town or village is a common sight—an increasingly common one, as climate change shrinks summer sea ice. So while the FWS currently is tackling the issue of people killing polar bears, its approach may come as a surprise. Real-world conservation stays firmly rooted in science, but with a clear view of conditions prevailing in polar bear country. Marine Mammal Protection Act recognizes the importance of traditional, subsistence harvest and can only limit it in the direst of circumstances,” Regehr explains. Its short forelimbs made liftoff impossible, though they may be the evolutionary remnants of an ancient ancestor’s flight-giving wings. A forelimb fossil discovered in Mongolia showed quill knobs like those found in many modern birds.


With cutting-edge 3-D filming technology and CGI, Flying Monsters 3D recreates spectacular pterosaurs and brings these giant flying creatures to life.
Learn how millions of creatures can disappear in a geological blink of an eye—and see what might be next. Scientists believe Aucasaurus probably attacked in packs, pushed past adult titanosaurs guarding nests, and picked off baby titanosaurs as they hatched. A search of Salafia's papers revealed a handwritten memoir in which he recorded the chemicals he injected into Rosalia's body: formalin, zinc salts, alcohol, salicylic acid, and glycerin. Under the Sea introduces some amazing creatures from the Great Barrier Reef and beyond, and shows you how their habitat is in danger—all with a bit of humor from Jim Carrey as narrator.
From day trips and scenic discoveries to luxurious girls weekends, travel tips, and insider scoops, our editors will give you all the information you need to enjoy your stay Up North.
First deployed in 1998, the platforms have endured the same destructive conditions as Titanic itself.Because the scientists know precisely how thick the platforms were at deployment, they allow researchers to gauge exactly how fast metal degrades at the Titanic site. Nargeolet, co-leader of Expedition Titanic, saw that the crow's nesta€”previously seen still attached to the forward masta€”had disappeared altogether, apparently damaged to the point where it snapped off and fell to an as yet unidentified location (interactive Titanic wreck diagram). But archaeologists are increasingly confronted with demands to let past generations rest in peace.
Puede eliminar las cookies que ya estan almacenadas en su ordenador, pero pueden impedir el uso de partes de nuestro sitio web. Visitors might notice a higher level of supervision here, though—armed wildlife agents patrolling on ATVs to keep polar bears from trick-or-treating the kids. These telltale features are evidence of where ligaments attached flight feathers to bone and are considered proof that Velociraptor sported a fine feathery coat.The dinosaur's plumage may have been used for mating or other visual displays, similar to how modern birds use their colorful feathers, or to help regulate body temperature. Alcohol, along with the arid conditions in the catacombs, would have dried Rosalia's body and allowed it to mummify. Expedition Titanic's data should help experts predict how long the wreck will remain relatively stable."We're trying to bring the actual hard data to the people who can make those determinations," Lange said. The feathers might also have helped females protect their eggs.Velociraptor highlights many of the numerous similarities between dinosaurs and birds, which go far beyond the skin-deep appearance of feathers. Glycerin would have kept her body from drying out too much, and salicylic acid would have prevented the growth of fungi.
Real Pirates traces the fascinating history of the Whydah, a ship that began its voyage as a slave ship in 1715 before being seized by the pirate Sam Bellamy and his crew. The Science Museum has produced more Omnitheater films that all other science museums in North America combined. Its goals: to use acoustic imaging, sonar, and 3-D video to virtually preserve Titanic in its current state and to help determine just how far gone the shipwreck is and how long it might last. Like birds, Velociraptor had hollow bones, tended nests of eggs, and probably behaved in similar ways.Despite their birdlike plumage these dinosaurs were not fliers. The Science Museum Omnitheater was just the second in America and is the only moving dome Omni in America. Their short forelimbs made liftoff impossible, though they may be the evolutionary remnants of an ancient ancestor's flight-giving wings.Velociraptor was probably one of the more intelligent dinosaurs, because it had a large brain proportionate to its body size. In 1984, Barry Clifford discovered the wreckage and found the artifacts that you can see today in the Science Museum exhibit.
It was formidable on land and, as the name suggests, almost certainly covered ground quickly.
Between Body Worlds (2006), A Day in Pompeii (2007-2008), Star Wars (2008), Titanic (2009-2010), The Dead Sea Scrolls (2010) and Tutankhamun (2011), the Science Museum has had the opportunity to share some amazing finds and stories in the last few years.
Big, with his mouth taped shut and a towel over his eyes, was completely docile, as inert as luggage. He behaved like a gator basking in the sun rather than one in the middle of a science experiment.Gregory Erickson, the scientist, stood a few paces away, grimly holding a plastic pole tipped with a little square plate called a force transducer. Erickson also intended to retain all his body parts, which explained his serious countenance.A man on the gator's back removed the towel and the tape.
Erickson presented the force transducer to the largest tooth at the back of the right upper jaw—and the jaws snapped shut."Trouble, we got trouble!" Erickson said as the gator, pole firmly clamped, began to lurch in his direction.
Erickson, a paleobiologist at Florida State University, is an expert in the feeding behavior of tyrannosaurs, including the bite marks left on bones. That research spurred him to find out more about bites in general, which is why he's out here moonlighting with crocodilians.We loaded Mr. Big on an airboat to be towed overland back home to Lake Griffin, about an hour to the south. We spent the night lakeside, testing ten more gators that had been freshly yanked from the water. Instead of scraping away the sandstone overburden on a nicely articulated ceratopsian, they might point and click on a computer screen, pivoting digital bones.These paleontologists tend to be on the young and idealistic side, determined to intensify the scientific rigor of their profession. Their goal is to hunt not just for dinosaurs but for something even harder to reconstruct—how dinosaurs functioned and behaved.They are tackling difficult questions:Were dinosaurs fleet of foot or ponderous? And how old did they get?Did they use horns and frills and spikes in battle, like they do in the movies? Were these unusual anatomical structures part of the business of attracting mates?How did one group of these creatures develop the ability to fly?These new scientists are a diverse bunch, emerging from evolutionary biology, biomechanics, botany, physiology. In recent years the field has produced feathered dinosaurs from China, egg-laying dinosaurs from Patagonia, and a host of new dinosaur species, such as the scale-breaking Argentinosaurus and the fearsome Giganotosaurus.
In the field we find direct evidence of a lost world ruled by titanic creatures, thriving all over the globe from 230 to 65 million years ago, during the Mesozoic era.And the field has charms that the laboratory can't match.
The field is the staging ground for that whole Indiana Jones thing, for the type of charismatic, rock-star scientists who hang out in dinosaur graveyards with shovels, picks, plaster, graduate students, and personal documentary film crews.But perhaps the very glamour of dinosaurs has spawned the backlash, the willful retreat to scientific basics by Greg Erickson and researchers like him. If you study fossil mollusks, for example, you aren't likely to be asked to become a scientific adviser for a Hollywood blockbuster. The new generation of scientists wants to put constraints on all the hypotheses flying around, and they think that the truth about dinosaurs—and dinosaur behavior—won't be uncovered with bones alone."For 20 years we've done what we call arm-waving," says Jack Horner, a legendary bone collector. Now we're sitting down, we're saying, We've got all these ideas, are they real?"'Horner can arm-wave like a champ, as he will admit. Since 1991 he's been arguing, for example, that Tyrannosaurus rex, the very emblem of predation, the killer of killers, was actually just a scavenger, an eater of the dead. Those banana-size teeth weren't for ripping live flesh, says Horner, they were for crushing the bones of a carcass.
This is vintage contrarianism, and Horner so far has failed to persuade many of his peers, who point out that T. Hyenas, for example, are scavengers one day, predators the next.But in any case this is precisely the kind of argument that can't be won by speaking louder than one's opponents. And paleontology—if the new generation has its way—will be seen as a no-nonsense field, a hard science, in addition to being a thrilling subject built around the bones of large, scary animals."This is where we have the rhino heads and the manatee heads," Lawrence Witmer is saying. Here's a bag of alligator parts."We're in the deep freeze of his laboratory at Ohio University in Athens. They belonged to creatures that died, or were killed for some other reason, and were then obtained by Witmer for research.
I keep thinking Witmer is about to produce the horse head from The Godfather.Witmer reconstructs the soft tissues in dinosaur heads. It turns out that a dinosaur of the Triassic period, 248 to 206 million years ago, had anatomical features remarkably similar to those of a contemporary alligator or seagull.Witmer recently caused a stir when he said that artists had long put the nostrils of dinosaurs too high on the head.
He wanted to see if there is a correlation—whether the bone of the nose reveals the location of the fleshy nostril. He found that as a rule there is such a correlation.Witmer then examined fossils and discovered that in modern renditions of dinosaurs the nostrils had always been misplaced. Nostrils in that location would heighten the animal's ability to nuzzle a potential food item and decide whether it was biteworthy.Witmer investigated another paleontological presumption, the notion that Triceratops and other plant-eating dinosaurs had cheeks, like cows or horses or humans.


Conventional wisdom said these cheeks were like feed bags, helping the animal chew and re-chew vegetation.
Witmer, to his surprise, discovered that animals with cheeks have bone structures that are lacking in Triceratops and other herbivorous dinosaurs. Triceratops, he thinks, had something more like a bill or a beak.The plant-eating dinosaurs may have clipped vegetation off plants with these beaks and then swallowed the material pretty much intact.
He explained how he dissects them to examine soft tissues and how he uses his findings to flesh out model dinosaur heads.
Think of how dinosaur paleontology has been dominated by "the whole animal," by spectacular specimens, huge skeletons that can fill the entrance hall of a museum. Thrown into the mix is the stunning fact that some dinosaurs lifted off the ground entirely.How did flight develop?Did the first airborne dinosaurs merely glide, or did they flap?Did the flight stroke evolve from other types of motion, such as grabbing prey or trying to elude a predator?
There's recent research at the University of Montana showing that baby birds, for example, start flapping when ascending an incline.
Birds have hollow bones, feathers, wings, reduced tails, and wishbones, each characteristic designed for flight. And yet each of these traits or something like it appears in the fossil record before birds flew.The dinosaur fossil record is actually rather poor.
In some bone beds there are so many tiny skeletal fragments you'd think the creatures had been dropped from a plane.That's why dinosaur behavior is so difficult to fathom from just bones—why the task of understanding dinosaurs is truly like trying to squeeze blood from a stone.
Some would argue that dinosaur behavior is a topic all too similar to extraterrestrial life—long on speculation and short on data.Gatesy and other paleobiologists are struggling to ascend what Witmer calls the Inverted Pyramid of Inference. Imagine an upside-down pyramid with, at the pointed bottom, the word "bones." Bones are the known commodity, the solid evidence. But you can at least hold them in your hand.Above bones on the inverted pyramid are soft tissues.
In 1853 paleontologist Richard Owen (who had given dinosaurs their name a little more than a decade earlier) staged a celebrated sit-down dinner in London. An engraving of the scene created a national sensation in Great Britain.Bone hunters scrambled to find ever more spectacular specimens. By the early 20th century the preeminent ambition in the field was to mount a skeleton dramatic enough to scare the bejabbers out of a schoolchild.Roy Chapman Andrews's journeys to Mongolia's Gobi in the 1920s were worthy of a Cecil B.
DeMille movie—great caravans of camels stretching into the wasteland, with Andrews packing a pistol and posing on bluffs with jaw thrust forward.But just two decades later the heroic age of dinosaur collecting was over. Bakker, building on the work of his mentor, Yale's John Ostrom, said that dinosaurs were not cold-blooded, but rather warm-blooded, active, quick. Birds, Bakker said (again, echoing Ostrom), are themselves the direct descendants of dinosaurs.The new image carried the day. The "raptors" are so savvy they seem on the verge of inventing spaceflight."I'm a method paleontologist," Bakker said one day in Boulder, Colorado. I want to smell what the megalosaur smells, I want to see what he sees."From a cigar box on the table he pulled a T.
He thinks he's found evidence in the teeth of allosaurs, meat-eaters of the Jurassic, that those dinosaurs dragged huge prey to their nests to feed to their babies. It can't possibly turn into a laboratory science."People who don't understand paleontology try to make it physics," he said.
Did it have the leg muscles to sprint 45 miles an hour (72 kilometers an hour) as some paleontologists contend?Hutchinson doesn't think T. Chickens run well, but a 13,000-pound (5,900-kilogram) chicken, Hutchinson has calculated, would need to have 62 percent of its mass in each leg.Hutchinson also studies elephants and has made several trips to Thailand to analyze their locomotion. Then he chases the elephants, shouting "Bai, Bail" which means "Go, Go!" In videotapes he captures the movement of the white dots.What Hutchinson sees in the tapes doesn't look like running. At least not exactly."The best definition of walking is that the body swings over the leg like a stiff, inverted pendulum.
They keep at least one leg on the ground at all times—like a walker—but the white dots move down then up, indicating a bouncing gait.Hutchinson showed me how to use his computer program to move muscles around, to attach them at different places on the bones, altering the leverage. By playing around, I'm pretty sure I created a dinosaur that couldn't do much of anything but fall over backwards."I could spend all my life on this, analyzing every little data point," he said.
Dinosaurs left tracks.One summer day I checked out some dinosaur tracks at an abandoned mine in the Rocky Mountain foothills near Grand Cache, Alberta, Canada. I was with Rich McCrea, a 33-year-old doctoral candidate at the University of Alberta, who has scrambled over almost every square inch of exposed rock.McCrea likes tracks. When he presented his master's thesis, he jokingly told the professors he'd love to find a six-footed trackway. One of McCrea's associates jokes that, to judge by most dinosaur tracks, these creatures couldn't turn.The mine is at the end of a dusty road that until recently was heavily used by coal trucks. The miners sliced off a chunk of a mountain, and there's a wall of stone more than two miles (three kilometers) long.
The rock face is covered with footprints—"totally polluted," McCrea says admiringly.Some go this way, some go that way. Some tracks strongly suggest herding behavior, and McCrea thinks there's evidence that meat-eaters stayed clear of the deep muck of coal-producing marshes. On some of the dark rock surfaces, remnants of swampy terrain, there are only plant-eater tracks. The mine, after all, was a fairly recent operation, and the rock faces sheer off regularly, meaning there are always new exposures.
He'd gone with some colleagues to Greenland—yes, even the most dedicated digital bone manipulators spend time in the field—and found thousands of tracks. Some tracks had an odd, bulbous structure at the end of the third digit, like a miniature volcano had erupted. He and a student at Brown bought one from a nearby farm and coaxed it to walk across a variety of hard and soft surfaces, including thick mud. The turkey didn't much care for this, but the tracks it created offered a revelation: All those different dinosaur footprints could have been made by the same species. What varied was not the type of animal but the type of surface.And that odd, volcanic shape at the end of the third digit? And the mystery of that event has hardly been solved.So even before dinosaurs became extinct, they were disappearing in this part of the world.
That is why it's so important for the discipline to go beyond the bones and truly understand these creatures and their environment. The big impact may have been merely the final blow.The end of the Cretaceous was a time when the global climate was changing and the sea level dropping.
New species arrived, perhaps carrying deadly microbes.No wonder it's such a haunting scenario.
Our world today is undergoing a climate change, a period of emerging pathogens, a rapid mixing of Earth's biota, a loss of biodiversity, and a virtual shrinking of the entire planet.Currie and I passed the afternoon in a remote part of the park, looking for new bone beds. We came upon a hillside covered with fragments, including some preserved inside unusually large nodules of ironstone. Or it might yield nothing but shoulder bones—the kind you look at for a second, then toss over your shoulder. But it was still exciting, because what we don't know about dinosaurs is far more than what we know. No matter how you practice it—with shovels or computer programs, with fossils or rhino heads from a freezer—this is still a new and evolving science.



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