© Andrew Derocher
11/11/2015 6:58:01 PM
What a Difference a Year Makes
The wicked winter that brutalized eastern Canada and U.S. earlier this year was, in some ways, a boost to the polar bears of Hudson Bay. The polar vortex that wreaked havoc in the East resulted in some serious sea ice that lingered longer in some parts of the bay this year compared with the past few years.
Does sea ice matter to polar bears? Without a doubt. Sea ice is the surface over which the bears travel, hunt, mate, and in some areas, den and produce cubs. More ice is good for bears: as long as it is the right type of ice. Thick multiyear ice isn't good habitat, but solid annual ice that persists late into the summer is great.
From our satellite-tracked bears, we could see that many of the bears were able to hang out on the ice for a few weeks longer this year. Did it matter? For sure it did for those bears lucky enough to be in parts of Hudson Bay where the ice lasted longer. Other bears, however, were less fortunate. They were forced to swim to shore earlier and were less able to get an extra seal or two; they also had to suffer through more time on land with less food.
The net result was that bears in 2015 were highly variable in body condition. Mothers with cubs-of-the-year were in short supply and the one we did see had only a single cub that looked far too small for having attained its 11-month birthday. The one mother with a single yearling seemed to be doing OK, but the dearth of new recruits to the population remains an ongoing concern and a key mechanism behind the slow decline in abundance.
The core monitoring area centered on the denning area between the Churchill and Nelson rivers is down by about 30% since I first came here over 30 years ago. Perhaps that's no big deal, but combined with sea ice loss documented by satellites and the predicted future loss from sea ice scientists, I worry about this population.
Seeing polar bears and being out with them on the Tundra Buggies® is magical. Churchill wouldn't be Churchill without them. On the bright side, I saw an adult male that was as fat as any adult male I've ever seen here. Descriptors bandied about included Jello-butt, Jiggle-butt, J-Lo, and Kardashian. Being slightly ignorant of pop-culture, I had to check out the last two potentials and I figured them out quickly enough (we have the Internet on Buggy One where we do our media and outreach).
Within the context of our somewhat more scientific but qualitative fat index (1=skinny, 5=obese), this big guy was a 5. Oddly, within minutes of seeing the big fat guy, a lean and lethargic 2 came walking by. There are always winners and losers in a population.
It was great to see the bears looking a lot better this year. It was a far cry from the conditions a few years ago. Fat is where it's at for polar bears. No polar bear ever looked at its reflection in a pond and thought, "I'm too fat." The big fat guy could easily go for another couple of months without running out of energy. The lean male needs sea ice and the sooner the better.
It's warmer than it should be this week. There's no ice on Hudson Bay of any significance. When will the bears take off and return? Now it's up to the weather conditions-and the sooner it gets cold, the better. Climate patterns suggest we're a couple of weeks away from freeze-up. Would I bet on that? Not a chance.
Most bears would be OK with two weeks but not all. All in all, I'm coming away relieved about 2015. It won't go down in the record books as a bumper crop of cubs and yearlings but at least it won't be etched in my memory as a tragic year.
Now I'm looking forward to the climate talks in Paris. I'm not going to be there personally. but I'll be there in spirit. It's our best chance to finally do the right thing: global targets to reduce emissions. It's time to get serious. The science is clear so now we need action.