Susan Crockford,
That is the fifth yr out of the final seven that sufficient sea ice has shaped alongside the west coast of Hudson Bay by mid-November for bears to have the ability to head out to the ice, simply because it did within the Nineteen Eighties.
One of many unbiased polar bear guides on the bottom close to Churchill had this to say concerning the bears and freeze-up circumstances this yr:
“Bears began leaving on November 10; conservation emptied the jail on the tenth as effectively.”
‘The jail’ is the Churchill Polar Bear Alert Program’s ‘holding facility’. Whereas the Alert program of us haven’t launched a report for this week (gee, I ponder why?), close by vacationer outfit Nice White Bear Excursions not solely confirmed the bears had been launched from jail however posted an image of a ‘inexperienced dot bear’: the mark placed on downside bears launched from the holding facility to maintain observe of them. Bears should not launched earlier than there may be ample ice alongside shore for them to maneuver out. Nice White Bear Excursions have been monitoring bears transferring offshore.
This data suggests the common date for bears leaving shore will possible become 12-14 November, once more sooner than the common for the Nineteen Eighties (16 Nov +/- 5 days) (Castro de la Guardia et al. 2017). That makes 5 out of the final seven years (2017, 2018, 2019, 2020, 2022) since 2015 that bears have left about the identical time as they did within the Nineteen Eighties.
Whereas there are nonetheless be a couple of bears on the shore of Wapusk Nationwide Park that appear to be in no hurry to depart, a couple of stragglers doesn’t imply there isn’t ice obtainable for searching.
Sea ice circumstances on Hudson Bay
Sea ice protection for week of 12 November, 1971-2022:
This quantity of ice is greater than the long run common for this time of yr (week of 14 November), based on the next CIS comparability chart, the place blue is greater than common and darkish blue is rather more than common:
How that appears on the same old ice chart for Canada, 16 November 2022:
Bears in no hurry to depart shore
Some bears in good situation look like in no hurry to get out onto the ice, as the photographs beneath from 12-17 November on the shore of Wapusk Nationwide Park, courtesy Discover.org. This phenomenon appears to reflect the reluctance of some bears in early summer season to go away the retreating ice even when there may be little or no left.
Solely a few WH bears tagged by Andrew Derocher’s group had left shore by 11 November and he hasn’t but up to date this data. As he’s executed up to now, chances are high he gained’t put up one other monitoring map till the bears are all offshore, so we gained’t be capable of inform when most of them left. However maybe he’ll shock us this yr.
References
Castro de la Guardia, L., Myers, P.G., Derocher, A.E., Lunn, N.J., Terwisscha van Scheltinga, A.D. 2017. Sea ice cycle in western Hudson Bay, Canada, from a polar bear perspective. Marine Ecology Progress Sequence 564: 225–233. http://www.int-res.com/abstracts/meps/v564/p225-233/
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