Here's why people thought dead polar bears had washed up in Scotland

The first time a story about dead polar bears in the Scottish Isles popped up in the news, it quickly went viral. That was back in 2010, and it turned out to be an April Fools' joke. The farce fooled the media, and now, a similar story is floating around. According to headlines, three furry, white carcasses have turned up in the Inner Hebrides – and there are photos to boot:

Image: Friends of Colonsay/Facebook

According to initial reports, the carcasses had hooves, smelled of blubber and were covered in hair. The islands of the Inner Hebrides lie 1,600 miles south of the nearest polar bear habitat, so it's no surprise that locals were taken aback. "We must assume that a small [polar bear] family was marooned on an ice floe which melted, causing them to drown," one onlooker wrote on Facebook. "How incredibly sad," wrote another.

The real story, however, is a bit less outlandish: these are whale carcasses.

You might assume it should be easy to tell the remains of whales and bears apart, but there's good reason for the confusion. As blubber decomposes, enzymes cause the lipids within to break down. This "autolysis" gives the blubber a stringy (or "furry") appearance. The same can be said for other tissues, like muscle:

The colour of the fatty tissue might also throw you off. We tend to assume blubber is pink, but that rosy hue is thanks to the dermis, blood and connective tissue. Once separated, blubber itself is relatively pale:

Whale skin and blubber ("muktuk") image: Lisa Risager/Wikimedia Commons

"We have had a number of these sort of cases over the years, and are confident that these are highly autolysed cetacean carcasses," says the team at the Scottish Marine Stranding Scheme (SMSS). "We cannot see the carcasses having any limbs, nor fur, or a skull with teeth that would identify them as any species of the Ursus [bear] family."

There's also temperature to consider. The waters around Scotland are currently 11-12 degrees Celsius (about 50°F) – far too warm for stable ice floes. Polar bears are capable swimmers, but the longest jaunt ever reported was just over 400 miles. And that is an extreme case: these animals rarely swim over 30 miles at a time.

Earlier this year, a polar bear did turn up in Iceland (where it was shot and killed ), but while the Nordic island country is just 766 miles from Scotland, the bear was found on the northern coast, nearly 200 additional miles closer to its home range.

"A polar bear either swimming or floating [to Scotland] is logistically impossible," says SMSS. "That makes the possibility that any polar bear reached us in identifiable condition highly questionable ... not to mention three, of a similar size, on one small island off the West coast."

But what about those hooves, you say? Friends of Colonsay, who posted the initial photos of the "bear" remains online, chalk that one up to a misidentification amid all the excitement of the strange discovery. "The smell made close examination difficult so theories and imagination were boundless," they explain. "Suggestions included extra terrestrials, a failed scientific experiment, a blue whale that had been broken in pieces by a submarine etc. So the hooves were a mistake, but quite understandable at the time."
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Top header image: Ray Muzyka/Flickr