Last night I couldn't sleep. I kept replaying in my mind the nine day endurance swim a polar bear and her cub attempted, due at least in part to climate change. I kept imagining the mother swimming on and on, through water as deep as 3400m for 232 hours straight. She never stopped, and was not carried by currents; rather she was continuously pushed away from her path and had to fight the current. No one knows when her cub died, but the scientists who reported the findings concur that the most reasonable explanation was that the cub likely died from exhaustion before the 687km swim was completed. Imagine the scenario. A lone polar bear swimming through an endless dark blue sea with her young cub following her, valiantly trying to keep up. Somewhere out there in that deep sea, where the ice used to be she must turn her head and watch her cub succumb to the depths and there is nothing she can do. To survive she must keep on swimming, hoping that the ice will appear on the horizon soon. Imagine her grief. Her baby is gone, her constant companion, lost to her. Don't believe it didn't hurt her. It did.
I'm getting ahead of myself. Let's get some background. Last night, just before going to bed, while browsing #climatechange on Twitter I discovered the story of a female polar bear who swam for nine days non-stop to find ice; tragically losing her yearling cub along the way. But, no matter what online newspaper I checked, the story was more or less a cut and paste job with the same sketchy details. I went to bed in a state of grief for the animals, my mind churning with questions. This morning I got up determined to get to the bottom of this sad tale, if only to get the story straight in my head. Silencing the smart-asses commenting online about why the polar bear would swim away from land if it had to swim for nine days had its intriguing potential as well. Getting access to the source meant purchasing the article from Polar Biology Journal, but I had to know the facts, so I paid the 42 Euros and settled down to learn what really happened.
The first thing I wanted to know was when this happened. Not one online article reporting about this story gave any dates or time frame at all. Secondly I wanted to know why a polar bear would leave land and head out to sea. Without any expertise on the subject I was going with my gut, something wasn't adding up, it didn't seem right that a polar bear would plunge into deep water for a swim of undetermined length and put their offspring at risk unless there was a very good reason.
So with these two questions at the front of my mind, I dove in to discover what the article Consequences of long-distance swimming and travel over deep-water pack ice for a female polar bear during a year of extreme sea ice retreat had to say...
I read the 10 page article with a feeling of gratitude, because after ploughing through endless media hype it was a relief to read something so completely devoid of emotive, blustering language. Finally, information that was useful; where the facts were plain and easy to see. I am glad that I read this article and didn't let the media influence my perception, because if I had stopped at the fence I wouldn't have found out that this event happened back in 2008. Yes. This is old news.
Here is how it really happened. Our polar bear and her yearling cub were captured by helicopter dart on August 23, 2008 on the Alaska Beaufort Sea coast (69.7188°N, 152.5621°W). The mother was equipped with a GEN-III PTT radio collar which included an on-board GPS unit and an Argos UHF satellite uplink. The collar was also equipped with a temperature sensor. At the same time, during capture the polar bear had a sterile temperature logger implanted into the base of her tail. Nothing was done to the yearling. When the procedures were finished, the bears were recovering normally from immobilisation and there were no other bears in the vicinity.
Three days later the polar bear (named 20741) and her cub began their swim into the sea. Because there is no data on the cub, we only know that the mother swam from 06.00hrs ADST on 26 Aug, 2008 until 22.00hrs ADST on 4 Sept, 2008. This was confirmed when the data was retrieved from the collar after her recapture on Oct 26, 2008. However, even though this is where the media stops telling the story, her journey was not yet over. The ice she did find was so insignificant that it didn't even show up on AMSR-E sensors and she had to move on once again after two days. She went back into the water at 00.00hrs ADST on 7 Sept, 2008 and arrived again on marginal sea ice at 04.00hrs ADST on 8 Sept, 2008 having swum another 80km. She then walked on marginal sea ice towards sea ice for 4 days (8-12 Sept) and then once she reached the sea ice rested for five days (13-18 Sept). Between the 18 of Sept and 26 of Oct, 2008 she walked approximately 1440km and was recaptured near the Canadian border (69.7291°N, 141.0938°W) where the collar and implant were removed. She had lost 22% of her body mass.
Well, the first question has been adequately answered, but what about the second one. Why did she do it? The report doesn't say but with a little digging on Wikipedia I learned that polar bears follow the seal population and in particular, in the Beaufort Sea the polar bears habitually travel to the sea ice north of the land during the summer to where the seals are. So she was looking for food. Simple. Did she expect the sea ice to be so far away? It looks unlikely, because according to the Polar Biology article it states that as recently as the 1980s the sea ice "...remained within the near shore regions of the Alaska Beaufort Sea coast. (Cosimo 2002)" But goes on to point out that in the following decade the sea ice loss was the "greatest in the entire Arctic" They speculated that until recently swimming "between land and pack ice would involve tens of kilometers instead of hundreds of kilometers". They attribute this loss of sea ice in summer to climate change and express concern that a continued trend such as this will certainly affect the stability and health of the remaining endangered polar bear population.
As I close this post, I wish to remind you that this story is over 2 years and 3 months old (if you count from the time of recapture and availability of firm data) with the press publishing it yesterday as though it just happened. To be fair the journal article they sourced their news from was only published online Jan 14 of this year, but why not report responsibly? I'm not going to propose any theories about the motivations of the media, but I will suggest that everyone take this example to heart and question the validity of everything you read from mainstream media. In this case, it's what they purposely left out that caused the greatest reaction. What's even more disturbing is from all the comments I have read from all over the Internet not one person asked when this actually happened.
For the little cub that drowned, even though you are long gone. I will think of you today and of the epic journey you took to survive in a world that was betraying you. Your death will not go unmourned.
Originally published on Paradigms Bend Jan 27 2011