Polar bears aren't exactly known for their "sharing is caring" attitude, but when a huge dead whale turned up on Alaska's Barter Island, the carcass quickly turned into a predator party. It seems even these territorial animals can set their differences aside when there's enough meat to go around. 


 

The incredible footage, recently posted by the Alaska Life Facebook page, was shot back in 2013 by Alaskan resident Sandra Chandler. (The details surrounding the encounter are a bit hazy, so we've reached out to Chandler for more information.) 

It's very likely that this whale didn't end up on shore through stranding, but was instead left behind by the local Iñupiat community after a traditional whale hunt. In 2012, a similar hunt lured some 80 polar bears to a beach in the Alaskan city of Kaktovik.

"They know the time of year that the meat starts to show up on the beach," Steven Amstrup, chief scientist at Polar Bear International, told National Geographic at the time. In fact, these interactions have been documented since the 1970s. 

Chandler's video description seems to jibe with this scenario. 

"The bears [are] eating what's left after the whale was cut up," she explains. 

A polar bear's range can span thousands of miles – far more than any other species of bear – so pinning down where these diners came from is a tricky task. Surveys have shown that bears arrive on the island at different times throughout the whaling season, so it's safe to say these individuals didn't all hail from the same place. 

The later arrivals would have had the toughest journey: as sea ice melts away, bears have no choice but to swim for their supper. It's a risky manoeuvre, but without solid ice to hunt from, fat-rich whale on solid ground is an alternative that's far too enticing to to turn down. 

The bone piles that accumulate after these hunts have become an important food source for many lingering bears, too. Since the late 1990s, the ice-free season in the southern Beaufort Sea has lengthened by about a month, prompting the Barter Island bears to extend their stay. 


 

 

Gatherings like these provide a rare opportunity to survey the health of Arctic polar bears, and recent studies have found that bears hitting land may enjoy an interesting advantage: those who swim south through the Beaufort take on less mercury than bears who opt to chase the retreating pack ice north. This could be the result of consuming fewer ring seals and more land-based prey.

But there are concerns, too. Experts fear that bear numbers on the island will increase in the coming years – and that might translate into more frequent interactions (or clashes) between bears and their human neighbours. Churchill, Manitoba, which sits along Canada's Hudson Bay, has seen a troubling spike in conflict since the local pack-ice season was cut short by rising temperatures.

With only a limited number of whale carcasses, it's possible that hungry predators on the island could turn to raiding local homes for scraps. "Every bear wants to maintain its weight, and they'll eat whatever they can," says Amstrup.

These ursine diners are not alone in enjoying the occasional leviathan lunch on Alaskan turf – check out this 2016 brown bear encounter!