A polar bear 'petted' a dog. Then a polar bear did what polar bears do: Ate a dog.

A video of an enormous polar bear in Canada gingerly patting a chained sled dog hit the Internet last week and quickly went viral. The Huffington Post lauded its "cuteness factor." The man who shot the video praised the bear for showing "that kind of heart toward another animal."

But reality soon intervened. Canada's CBC News reported that officials had removed three polar bears from the same property in Churchill after one killed and ate another dog. The owner of the site, who raises the sled dogs, told the network that the slaughter had occurred on "the only day we didn't feed the f—king bears, the only night we didn't put anything out."

The irony of the two incidents spawned commentary on the perils of the attributing human emotions to animals and imposing a moral code the creatures can't possibly be expected to live up to. They also renewed anger at the owner of the site, Brian Ladoon, who has long been a target of animal rights activists and conservationists who decry his chaining of dogs and luring of polar bears for tourist photo-ops.

Tom Smith views it all from somewhere in between. Smith is a wildlife biologist and advisory scientist with Polar Bears International, and he's spent his career studying bears of all sorts – polar, grizzly and black. He chuckled when he viewed the "petting" video this week, which he didn't exactly see as petting.

Bears have a sky-high "curiosity quotient" and tend to ask questions with their teeth and paws, which is why they sometimes tear up human campsites, he said. But he added that this is also a time of year when polar bears, who depend on sea ice for hunting seals, have essentially been starving for months.

"To me, it's like it's trying to see if the food's ready or not," Smith said, laughing. "It's not surprising that it would try to explore this dog . . . but I guarantee if you left that bear there long enough, it would say, 'I wonder what this dog tastes like?' I'd be sorely disappointed in a bear that didn't ultimately eat that dog."

To be clear, there is no indication that the bear in the video is the one that ate a dog, or that the dog in the video is the dog that was eaten. A Manitoba Sustainable Development spokesperson told CBC that authorities had removed the bear that killed a dog from Ladoon's Mile 5 Dog Sanctuary, as well as a mother and a cub, "because there were allegations the bears were being fed and the females' behavior was becoming a concern."

Which means that, yes, the bear and the dog in the video probably did peacefully coexist for at least a few moments – the kind of interaction that's been captured previously at the same site. And Smith said that doesn't surprise him, either. That's because bears are highly trainable and extremely motivated by food.

A little background: Ladoon is a painter who has taken it upon himself to save the Canadian Eskimo dog, a rare breed. He does this at Mile 5, a windswept and barren point on the Hudson Bay. According to many reports, some of the dogs are allowed to roam and "guard," while most are chained. Polar bears also show up, lured either by the smell of dog food or by food Ladoon puts out for them (Ladoon has previously both denied and acknowledged feeding the bears, which is illegal). Ladoon charges tourists to come see and photograph the polar bears, which have fiercely battled and killed dogs there in the past.

Ladoon has also said he keeps the polar bears in line. He told author Jake MacDonald that he'd "give them a little bird shot in the rear end if they needed it." He told journalist Jon Mooallem, who wrote about Ladoon in his book "Wild Ones," that he has trained them to back up at the sound of him pumping the action on his shotgun.

That's important, said Smith, who has spent lots of time in Churchill and has met Ladoon. We've all seen images of captive bears riding bicycles or walking upright. They typically do this because people are offering a bear food or threatening punishment. Polar bears with grumbling tummies would be similar, Smith said. They'd learn the rules, which in this case would be: Don't hurt the dog if you want to stick around and get food.

"Bears don't get old doing stupid stuff. So when you've got a human standing there with a gun, they learn very fast where the lines are," Smith said. "So it's not exactly a rare glimpse into a bear-dog alliance or something. That's what people would like, but it's just not the way the world works. Again, a very behaviorally plastic animal under great food stress, they can do a lot of tricks."

But that doesn't necessarily mean that polar bears see the world purely through meat-colored lenses. Smith referred to them as animals that aren't social by nature but also aren't anti-social. He said he has seen them "lounge around and play pat-a-cake" – with each other. He's also published a paper on flexible relationships between wolves and brown bears, which he's seen share fish.

"Can they be congenial without humans intervening? They can," he said of bears. "I'm not trying to take away from the joy people find in the wonderful range of behaviors bears can exhibit."

But, he said, the polar bear petting video "is a little different." It and its dog-eating peer are hungry bears. They're visitors to a place where food is present, and so are people who might harm them.

"It doesn't take away from the fact that bears can do that. But you always have to ask: Why would it do that?" he said. In this case, Smith said he believes, "the reason it's acting that way seems to be mediated by human intervention."