Polar Bears Going Extinct in Someones Eye Polar Bear Art Hands
You may have seen a recent viral video that showed a polar bear in the throes of suffering. The beast seems to be in the terminal hours of its life—its legs wobbling under its weight, its pupils widened in pain, its yellow fur hanging loosely off its basic—equally it gnaws on trash, lays down, and shuts its eyes.
Paul Nicklen, the conservationist who shot the video, said he hoped the haggard bear would reveal the true face of climatic change. "When scientists say bears are going extinct, I desire people to realize what information technology looks similar," he told National Geographic. "Bears are going to starve to death. This is what a starving bear looks like."
Millions of people saw the clip—and polar-behave researchers added some caveats. "It is what a starving bear looks like for sure, because I've seen some," Ian Stirling, a enquiry scientist emeritus with the Canadian government, told me. "Now, we don't know if that bear was starving to death, or if information technology was suffering from something else, without doing a proper necropsy. But it certainly looked similar it was starving."
Whatsoever the fate of that one comport, many more volition soon look much similar it. New research, published this week in the periodical Science, shows that bears are even more vulnerable to undernourishment than once thought. Polar bears have higher daily energy demands than other noon carnivores, the paper finds, and they may need to eat every few days to avert burning into musculus mass.
Fittingly, this new enquiry comes with some startling video of its ain. Equally part of the report, scientists recorded hundreds of hours of footage from small cameras strapped to polar bears, giving the team a unique "bear'southward-eye view" into the animals' lives. They witnessed solitary bears in the wild as they are rarely seen: hunting, swimming, mating, and just having fun.
The new video provides a trove of useful data for scientists fifty-fifty every bit the research confirms what they have long known: Every bit global warming steadily reduces the corporeality of ocean ice in the Arctic, bears will miss opportunities to snag their favorite casualty—fat, calorie-rich ringed seals—and many will weaken and starve.
Of form, you cannot only strap a GoPro to a polar bear. Anthony Pagano, a research biologist at the U.South. Geological Survey, learned that early, when a first attempt at this experiment went awry.
Pagano works at the bureau's Alaska Scientific discipline Center in Anchorage. He studies polar bears that live in the due south Beaufort Sea, the part of the Arctic Ocean that meets the land'due south northeastern coast. Beaufort Sea polar bears are among the outset of the species' subpopulations to run into population reductions due to climate change.
Every yr, the roughly 900 bears in the region endure a cycle of plenty and desire. Arctic sea ice reaches its maximum expanse by March, stretching all the style downwards to Alaska's north declension. For the next few months, the bears grub down, hunting in the fertile and shallow waters of the continental shelf. They become fat and happy. But as June turns to July, summer rut causes the ice to recede, and the bears follow the ice into the Arctic bowl, where there are fewer seals. They may fast for weeks at a time. At last, in tardily September, the ice begins to recover, and sometime in the adjacent few months—during the long night of Arctic wintertime—the bears return to their feeding grounds.
Scientists believe that the early springtime is of crucial importance to the bears, every bit information technology'south when they build upwards their fat reserve before the hungry summer. In April 2013, Pagano and his colleagues set out to better understand the bears' springtime habits. They located two female bears by helicopter, tranquilized them from the air, and tagged them with both a GPS tracker and a GoPro-mode video camera. About 10 days afterward, they tranquilized the bears once again and recovered the footage.
Except there wasn't whatsoever. The photographic camera's battery had encountered its first Arctic nighttime—during which temperatures tin can regularly achieve -twenty degrees Fahrenheit—and promptly conked out. Information technology wouldn't have been able to see anything, anyway, equally a slab of water ice had encrusted the lens. Regular cameras wouldn't be able to stand up up to the Arctic. Pagano needed a custom chore. He spent the next few months working with Mehdi Bakhtiari, an engineer at the visitor Exeye, who specializes in making custom wild fauna cameras.
By the next jump, he had iv new wild animals cameras that could endure the Arctic weather condition. Pagano and his team began a lengthy experiment. Every Apr, they would wing out, find a female person conduct without cubs, and subdue it. And so they would elevator the animal above the ice surface with a tripod, weigh it, and run some claret tests. They also outfitted it with a GPS tracker, an accelerometer, and one of the new cameras.
Between eight and xi days later, they would find the bears once again, recover the cameras, and run more tests. Afterwards successive runs in Apr of 2014, 2015, and 2016, they had hours of footage from ix bears.
This video lonely represented a major accomplishment in polar-conduct research. "We don't get to detect these animals much at all," Pagano told me. Bears spend about of their lives out on the ice, alone; and they can attack humans who get too close. Then scientists haven't known—and still don't know—what the 24-hour interval-to-day life of a polar bear is like.
So the team'south footage—days of moving-picture show of polar bears but being polar bears—was something special. The cameras showed bears spending hours of their 24-hour interval sitting near gaps in the sea water ice, waiting for a seal to surface to breathe. The footage caught bears trying to sneak up on seals who were sunning themselves on the ice. It displayed, even more than particularly, a acquit trying to catch seals past swimming beneath the ice.
"One bear was throwing chunks of ice in the water," Pagano said. The animate being seemed to lift up a piece of ice to a higher place its caput, stand on its hind legs, and chuck information technology into the water. "She did this repeatedly," he told me. "It's not clear why that private was doing that."
Even more spectacularly, the squad got to glimpse the polar-bear courting and breeding process. Courtship?, I asked Pagano. Do the males bring fish to the females or something?
He paused. "Commonly the males would simply harass the females until they would acquiesce," he said. "It varied depending on the individuals, for sure. But most typically the bears would follow and harass the females—and the females would effort to become them to create some space, would vocalize at the male person and paw at the male—only the male person would harass and canis familiaris the female person until she gave in."
The cameras faced to the front, and then researchers couldn't verify every instance of mating. "But in some instances, I could come across shadows on the water ice, shadows on superlative of the female," Pagano said. "Which was, aye, quite interesting."
Nearly chiefly, these observations allow scientists count how many seals each bear was able to take hold of. They paired this information with other data: the bears' blood examination data, their starting and catastrophe weight, and their movement as recorded past GPS and accelerometer. By comparison all those figures with data from a captive polar bear at the San Diego Zoo, they could measure the bears' metabolism rate—how fast the bears burn through energy.
The bears burn calories fast, and everything comes down to how many seals a bear can catch. The most successful bears were able to snag a seal every day or ii. Over the calendar week and a half they wore the cameras, those bears gained upwards to 44 pounds, or 10 pct of their preexperiment trunk mass. But bears that missed out on seals were every bit punished. Four of the nine bears shed up to twoscore pounds of body mass during the same length of time—and at least one had started called-for abroad its lean muscle.
"This highlights the banquet-or-famine lifestyle of these animals," said Pagano, who estimates that Beaufort bears in the springtime must eat an adult ringed seal every three days to maintain a healthy weight. "They're highly dependent on being able to grab seals to meet free energy demands. And since the ice is breaking up earlier every yr, it'due south reducing their opportunities to take hold of these seals."
Polar bears, the study found, have a higher metabolic rate than apex predators that live on land, similar lions, hyenas, or black bears. They burn energy at the highest stop of the range scientists had previously simulated—especially when "sitting and waiting" for seals to surface at a gap in the water ice.
The research also reinforces the general principle that marine mammals, like polar bears, burn energy faster than their terrestrial brethren. This suggests something nearly how polar bears became marine in the first identify: Their evolutionary predecessors must have institute seals to be so efficient (or delicious) that eating them was worth the high caloric costs of living on the ocean ice.
This new data volition help scientists meliorate runway polar-carry populations. "Yous can build better [population] models knowing what the feeding requirements are for these animals," said Øivind Tøien, a research scientist at the Plant of Chill Biological science who was not involved in the study. "It provides very solid data for the management of the polar bears. That'due south important."
He thought that the number of animals observed—9 bears, over 3 years—allowed for a robust finding. He praised the arduousness and robustness of the study. "Yous can't just walk upwards to a wild polar bear and say, 'Okay, I'd like to inject y'all with deuterium,'" he said. "And so you actually can't come up dorsum a few days later and say, 'Okay, I'd like to accept a blood test now.'"
1 of the few scientists who had last observed polar bears this closely is Stirling, the retired Canadian government ecologist. In the 1970s and 1980s, he found ways to successfully observe polar bears on Hudson Bay. Some of his studies were the offset to warn that climate change could endanger polar bears beyond the Arctic.
"I think the study itself is very interesting," he told me of the new paper. "It doesn't give us anything new on the big motion-picture show, considering we've had good information now for 20 or more years that the loss of body of water ice is causing lots of problems for polar bears. But the understanding they have of some of the physiological mechanisms are very interesting and valuable, particularly to physiologists."
He cautioned that polar bears in the Beaufort Sea may not resemble groups elsewhere in the world. "There are 19 unlike subpopulations of polar bears—and the ecological circumstances that each lives in are its own," he said. "The Beaufort Ocean is different. It's the simply population where—even in practiced times—females didn't breed for the get-go time until they were at least 5 years old. Convenance starts at historic period 4 everywhere else. You accept to be a little careful expanding [this finding] too far."
Just the Beaufort Bounding main bears—and the in one case-thriving bears of Hudson Bay, where Stirling showtime studied—make for skilful example studies because they have already suffered so much due to the loss of sea ice. Long-term studies accept found that the number of polar bears in both regions is decreasing, equally is the amount of trunk fatty on each animal. Mothers have lower birth rates, and the number of cubs who survive infancy is falling besides. "Those areas are giving united states of america a pretty good idea of what we can await in other areas as things continue to warm," said Stirling.
Some bears may already be taking extraordinary steps to survive. A serial of GPS-neckband studies have found that polar bears sometimes swim for days at a time at the terminate of the summer, when ocean ice is at its everyman and bears are in the least productive waters. Ane behave was tracked as it swam more than nine days across the Arctic Ocean without stopping to sleep. Another study, published recently in the journal Polar Biology, constitute that the metabolic costs of those multi-day swims are too extremely loftier.
"Putting the ii studies together does suggest that polar bears are but walking a finer line energetically than we idea, so things like long-distance swims could be even more detrimental than previously supposed," said Blaine Griffen, a biologist at Brigham Young University who led the swimming report, in an electronic mail. "These swims may reflect bears that are searching for food, but it is difficult to know why any detail animal chooses to make a single conclusion."
The body of water ice will keep to cook, and bears will continue to take catastrophic steps to save themselves. If carbon pollution continues unabated, and then models suggest that the Arctic Ocean will lose all of its sea water ice every summer past virtually the year 2050. (It will form again every winter through at least 2100.) The math here is simple and fell, equally Arctic sea ice exists in a linear relationship with the corporeality of greenhouse gas in the atmosphere. The average American emits plenty carbon to cook about 645 feet of summertime sea ice every year.
And as the ice melts, and breaks up earlier every yr—shortening the springtime feeding flavor—more than bears will starve. Polar bears do not have a natural predator in the wild, so virtually bears already die of one-time historic period, disease, or starvation.
"It's very like shooting fish in a barrel for people to understand," said Stirling. "A warmer climate ways less water ice, bears demand the ice to hunt the seals, less ice ways they don't go as much time to chase seals, and that'due south bad." Tøien agreed: "If Chill water ice disappears, and y'all have an animal that is capturing their prey on the water ice, and depends on that water ice—it's obvious what's going to happen."
For all the research, for all the delightful bear cams, for all the effort to save the species, there is only i step that can permanently protect the polar bear. "If climatic change continues unabated, we unfortunately will probable meet many more images of starving polar bears in years to come up," said Griffen, the Brigham Young professor. "The only viable, long-term solution to staving off the effects of climate change for polar bears, and for other species (including u.s.), is to reduce greenhouse-gas emissions."
Source: https://www.theatlantic.com/science/archive/2018/02/what-scientists-learned-from-strapping-a-camera-to-a-polar-bear/552083/
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