This story has been updated to reflect the more specific location of where the photographs were taken.
Our video of a starving polar bear has been seen by millions of people online over the past few days. For some, it's a symbol of what many polar bears may face in a warming climate. For others, it's a red herring.
So what can one gut-punch of a video really tell us? Quite a lot.
Here we answer some of the most asked questions we've seen about the video on Facebook, Twitter, Instagram, and elsewhere:
Why couldn't the film crew help the bear?
Watching the emaciated polar bear struggle to move and desperately dig for food in a trash can is hard to watch on video. For Paul Nicklen and Cristina Mittermeier, two biologists turned photographers turned co-founders of conservation group Sea Legacy, it was even harder to witness in person.
"Some have criticized us for not doing more to help the bear, but we were too far from any village to ask for help," Mittermeier wrote in a follow-up piece about the video," and approaching a starving predator, especially when we didn't have a weapon, would have been madness."
"In the end, I did the only thing I could: I used my camera to make sure we would be able to share this tragedy with the world."
What do we know about this polar bear from the video?
This polar bear is starving. The bear's thin frame and protruding bones are clear indicators of this, and its atrophied muscles suggest it's been starving for an extended period of time.
Without a full necropsy, it's nearly impossible to say whether or not the bear had some kind of disease. Some polar bears have been known to contract parasites, but like other bear species, polar bears are not that prone to diseases.
Nicklen noted that the bear showed no other signs of injury and had no visible scars. When polar bears engage with one another, the encounters can be brutal. It's rare to see a bear advanced in age with few visible scars.
"That bear is clearly severely malnourished," said Steven Amstrup, the chief scientist for Polar Bears International, in an interview Monday. "It clearly has the symptoms of starvation."
Do we know what happened to the bear since it was filmed?
Nicklen and Mittermeier recorded the bear in late August. They filmed it for as long as conditions were favorable. With the sun setting by day and the fall season quickly approaching, Sea Legacy was unable to continue working in the region. They do not know what became of the bear, but Nicklen believes it likely died within a day or two.
How are polar bear populations faring?
As a whole, polar bear populations around the world are not in immediate peril. Nicklen has described seeing polar bears in Russia's Arctic that are so fat they can barely walk. Scientists think that there may be more polar bears in Russia than anywhere else, but extreme remoteness and lack of resources have made formal surveys difficult there, leading to a lot of uncertainty and questions. And the bears aren't faring equally across polar regions.
According to Amstrup, some of the polar bears most at risk of population decline live in regions that have seasonal ice, like that surrounding far northern Baffin Island, near where the starving bear was filmed. The U.S. Geological Survey has published a map of where this ice extends. Seasonal ice melts completely in the summer and comes back in fall. Polar bears survive on stored fat during summer months.
"They use about two pounds a day waiting for sea ice to come back," said Amstrup.
What's happening to Arctic sea ice?
As temperatures warm, seasonal sea ice is melting earlier and coming back later. This extends the time that polar bears must survive on fat alone.
Arctic sea ice covers about a million square fewer miles than it did in 1979. The vast majority of scientists agree that melting sea ice has accelerated beyond the normal rate in the past few decades. The Arctic is one of the regions most impacted by a warming climate.
If warming continues, says noted polar bear scientist Ian Stirling, "the Arctic marine ecosystem as we know it now will no longer exist."
How do warming temperatures impact polar bears?
Polar bears are among the largest bears in the world, and they can weigh as much as 1,600 pounds. This means they need a lot of food to survive. Polar bears feed on seals, walruses, and whales and consume hundreds of pounds of meat in one meal. Unlike other types of bears, which can forage on plants and berries, polar bears are carnivores and need meat to survive.
Polar bears in the Canadian Arctic "feed almost entirely on a small species of seal," says Amstrup. "These seals hardly ever haul out on land."
Seals are adept swimmers and are capable of surviving long periods in the water. This makes it very difficult for polar bears to catch them in open water. Instead, they can use their power to overcome their prey on or through icy terrain.
And while some far north communities have recently reported seeing more polar bears around their homes, that doesn't necessarily mean their populations are growing. When unable to access ice, said Amstrup, polar bears often turn toward food smells coming from local villages or garbage dumps.
Less snowfall in Arctic regions also means polar bears may not be able to make suitable dens in which to have cubs—as has been the case in western Canada.
Canada's western Hudson Bay has been one of the most widely studied polar bear habitats where sea ice is declining. Some research has been inconclusive on whether this regional effect has been caused by human-induced warming temperatures, while other research says the polar bear population here could die out in 30 years.
"No biologist is saying all polar bears are in trouble right now," said Amstrup. "But those that are in trouble right now are giving us a signal for what's to come."