12/13/2011 4:14:20 PM
A Late Return to the Sea Ice
The latest ice map from Environment Canada, on December 9th, shows the western parts of Hudson Bay have frozen, so the bears are finally back on the ice hunting seals. There's still a lot of missing ice in Hudson Bay (the bright red areas), however, meaning it's far from a normal situation for the bears.
The map below shows the satellite-collar locations of Western Hudson Bay bears, as of December 12th. The bears are all doing different things right now: some are going south and some have gone north. There is definitely movement on the ice, which is great.
A map from ten days earlier, on December 2nd, showed that only half the bears had made it back onto the ice. The return to the sea ice—with some bears waiting onshore in areas with no ice—showed the same sort of variation that happened with polar bears coming off the ice this past summer. It appears that variation between individuals is increasing. This means that we'll see some bears doing fine but more bears doing poorly over time. And that was certainly evident in the bears we saw in Churchill this year, with some bears in good health but others in bad shape. We also saw fewer mothers with cubs.
Although it's good news that the bears are finally hunting, we need to keep in mind that this was a very late freeze-up. In the 1980s, freeze-up typically arrived by the end of the first week of November. Two decades later, that had moved to about November 20th. For the past three years, it has been December. These longer and longer ice free periods are straining this population's ability to survive.
Photo copyright Daniel J. Cox/Natural Exposures.