12/2/2011 3:14:24 PM
Where's the Ice?
By Dr. Andrew Derocher
It's easy to have the sense that the bears are back home when we're far away and the days are getting shorter and colder. All indications from Churchill were that the bears were heading out onto the ice. It was a "flash freeze." Or was it? Our satellite-collared bears tell a different story.
Many of the females south of Cape Churchill are still stranded on land and those that made it out on the ice didn't get very far. A strong wind from the south this week didn't help: it pushed away the near-shore ice, retarding the iceward movements of the bears and forcing many back to land. And so they wait.
The ice anomaly shows that Hudson Bay and the surrounding area is missing a huge amount of ice again in 2012 (the darker the red, the more ice missing). We've been missing ice all year in the Hudson Bay area. We suspect the bears really want to be much further out in the Bay because they usually follow the advancing ice edge - probably to catch some of last spring's naÌøve seal pups.
In the 1980s, Hudson Bay typically froze by the end of the first week of November. Two decades ago, that stretched to mid-November. For the past three years, freeze-up didn't come until December.
Hudson Bay isn't what it used to be, but we have little sense of what the situation for the bears is like at this time of year. It's -7 F (-21 C) as I write this. It's cold enough to make ice but the Bay holds a lot of heat and that has to be dissipated before the ice becomes thick enough for the bears. Less ice throughout the year means the Bay can heat up a lot more than it can with a nice reflective cover of ice.
Even the bears that headed north aren't doing that well. On November 29, a bear was shot during an encounter with sled dogs in Arviat, Nunavut. One has to wonder if some of the Churchill bears that have been feeding along with the dogs east of town don't learn to seek out dogs. It was encouraging to see Manitoba Conservation finally move to clean up the situation. It can only help the bears. The recent increase in the harvest quota for the Western Hudson Bay population (from eight to 21) appears unsustainable and will increase the rate of population decline.
2012 remains a bit of a mystery for the Western Hudson Bay population. Some bears were in fine shape but some were doing very poorly. Cub production seemed to be low but some mothers had chubby cubs. During tough times differences in hunting abilities really show.Time will tell but with climate talks in Durban, South Africa grinding along, there is hope. Unfortunately, Canada with two-thirds of the world's polar bears under its jurisdiction is dragging its feet once again. It will take leadership to stop global warming, but it isn't clear where that leadership is coming from.