Our week just wouldn't be complete without a dubious wildlife tale to dig into, and this one comes in the form of "mysterious mutilated whale corpses" that turned up recently on a Russian beach. While the story certainly sounds interesting, there's probably nothing very mysterious going on here. 

The accompanying images and video, which have been shared on several viral media platformsare being distributed by Central European News (CEN), an agency that has faced criticism in the past for its misleading and sensationalised stories. (Transparent pink-boned "mutant" frogs, anyone?)

The original footage was filmed and posted to YouTube last week by local resident Egor Rybalko – minus the dramatic overtones that now accompany his video. The facts surrounding this event are still hazy, but here's what we do know:

The footage was recorded on the shores of Chayvo Bay on Russia's oil-rich Sakhalin Island. Given that location, and judging by the size of the remains, we'd wager this is a dead grey whale. Media outlets make reference to several whale carcasses, but Rybalko's video appears to show the remains of just a single animal.

A small, locally endangered population of these gentle giants spends its summer months in the nutrient-rich waters off the northeast coast of the island, and a unique grey whale nursery is known from these waters, too. (If any whale experts out there want to weigh in on the ID, we'd love to hear from you.)

The advanced state of decomposition makes determining a cause of death almost impossible in this case, but the whale was likely buried by tide and wind power. 

It's also possible that those same forces actually unearthed the carcass after local officials buried it – we know firsthand just how difficult that task can be – but we suspect this is not what happened here. 

As we've discussed before after other beaching incidents, the stringy-looking "stuff" covering the huge skeleton is actually degraded blubber and connective fibre. As enzymes break these tissues down, they take on a "furry" appearance (and the visual result is perfect for hatching tales of mystery sea monsters).

Many of the bones on the beach reportedly appeared gnawed and mangled – and if you look closely, you'll see evidence of the likely culprits:

That's a bear right there! Images: Egor Rybalko/Screengrab from YouTube

This large Russian island plays home to the Sakhalin brown bear (Ursus arctos lasiotus), also known as the black grizzly or Ussuri brown bear. The animals – which are also found in the Amur and Ussuri River regions of the Russian Far East, northeastern China, the Korean Peninsula and Japan – are among the largest brown bears on earth, and one of the few subspecies that approaches Alaska's Kodiak giants in size. 

They might be impressively enormous, but Sakhalin brown bears are not the man-eaters they've been made out to be. In reality, the animals only rarely come into close contact with humans. As is the case with other ursids, however, they're particularly active at this time of the year.

The bears emerge from winter hibernation around April, and nursing mothers may have three, or even four, mouths to feed. A fat-rich meal like this whale carcass is a caloric treasure trove for the opportunistic animals – so it's no surprise that the beach was covered with paw prints. 

This kind of scavenging is actually common in places where land meets sea – particularly across the Bering Strait. Last year, brown bears demolished a sperm whale after it stranded on Alaskan shores. And whale bone piles that accumulate after traditional hunts have become an important food source for resident polar bears, too!



Top header image: North American brown bear, Eric Gorski/Flickr