Dr. Susan Crockford,
Although since 2015 at least the Polar Bear Alert Program in Churchill Manitoba usually issued and published its problem bear reports weekly during the ice-free season, this year has been an odd exception. Two reports in early July, then nothing. Yesterday, there was a dump of reports that had been compiled on 1 September and 7 October, according to their metadata.
There are still a few weeks missing, including the two most recent weeks but at least now we have a more complete picture of what’s been going on with problem bears in The Polar Bear Capital of the World that can be compared to previous years. Such reports in various forms go back to the late 1960s, although only those from recent years have been publicly available (Kearney 1989; Towns et al. 2009).
I will start with the most recent report, for week 13 (20-26 September), compared to previous years. The originals in pdf form are available here.
So far, 91 incidents have been recorded, 7 bears physically handled, and 5 bears ended up in ‘jail’ (the holding facility) at the end of the week.
2021 compared previous years
In 2020, the bears came off the ice so late in the season (mid-August) and the first Churchill Alert report was not issued until 31 August. So we really have to compare two reports: the same calendar date and the same number of weeks off the ice. First, the same calendar date in 2020 (21-27 September) was only week 5 for bears off the ice last year: they were likely not moving around much.
Week 13 for the bears (and for the community of Churchill) in 2020 did not occur until the third week of November when many bears had already left for the ice and this report was the second-last report of the season! That year was weird in another respect, as a huge patch newly-formed ice (undoubtedly with some bears on it) was blown offshore the previous week (13 November), disrupting the movement of bears onto the ice and causing some to stick around a few weeks longer than was actually necessary.
I think that the best comparison to make is between length of time onshore (i.e. comparing week 13 in 2021 to week 13 in 2020) and clearly this year has had fewer problem bear incidents than 2021 (91 vs. 116) but more bears handled (7 vs. 4) and more bears in ‘jail’ at the end of the week (5 vs. 0). There is no doubt that 2020 was a remarkably short onshore season for Western Hudson Bay bears in general, which meant a relatively quiet season for problem bears around Churchill and therefore not likely to be similar to 2021, when the onshore season began with a few bears near Churchill in the last week of June.
In other words, comparing a more ‘normal’ year than 2020 to this year would be more appropriate. See the reports below from 2019 to 2015 for week 13 from my own archive (or the closest date with a report).
It turns out that 2019 is not a great comparison either. Week 13 in 2019 was a full month later than in 2021, as most bears were not off the ice until early August (not quite as late as 2020 but later than has been usual in recent year).
Actually, 2018 is a better match for 2021: week 13 was also the last week in September that year. There were more problem bear incidents that year than 2021 (132 vs. 91) and similar numbers of bears in the holding facility at the end of the week both years (5 vs. 4), with the comment that “few bears were around” in 2018. There were no comments like that on the 2021 report (only a generic warning that appears on almost all reports so far) but it is perhaps safe to suggest that the same situation was true in 2021 as in 2018: few bears around at that time (more on this in an upcoming post). Keep in mind that fewer bears around Churchill in any one year doesn’t indicate a decline in abundance for the Western Hudson Bay subpopulation.
There was not a report published for week 13 in 2017 but as it happens, week 12 was also the last week in September (below), again showing relatively little activity:
In 2014, the Alert program developed a ‘zero-tolerance’ approach to bears in the town of Churchill after a near-fatal attack in 2014, and vigilance ramped up over the next few years leaving 2016 with much higher incident numbers by the end of the season. By week 13 in 2016, problem bear incidents were much higher than 2021 (133 vs. 91). As for 2017 and 2018, this suggests few bears around Churchill this year.
For 2015, I have only week 11 for comparison. However, week 11 fell only one week earlier than 2021 (mid-September) because the first bears were off the ice and causing problems the first full week of July (5-12) that year. There were still more problem bear incidents to that date in 2015 (109) than there were this year (91).
There is still no ice on the shore of western Hudson Bay as of this date (which is entirely normal, see chart below for the week of October 4) but there is still no way to know if this will be an early or late year for ice formation on the bay.
Kearney, S.R., 1989. The Polar Bear Alert Program at Churchill,Manitoba. In: Bromely, M. (Ed.), Bear–People Conflict: Proceedings of a Symposium on Management Strategies, Yellowknife, Northwest Territories Department of Renewable Resources, pp. 83–92. [courtesy M. Dyck, Gov’t of Nunavut] Pdf here.
Towns, L., Derocher, A.E., Stirling, I., Lunn, N.J. and Hedman, D. 2009. Spatial and temporal patterns of problem polar bears in Churchill, Manitoba. Polar Biology 32(10):1529-1537. http://link.springer.com/article/10.1007%2Fs00300-009-0653-y
via Watts Up With That?
October 9, 2021 at 12:29PM