Predictably, polar bear specialist Andrew Derocher has finally posted a tracking map of the Western Hudson Bay bears his team has fitted with collars and eartags–two weeks after bears were released from Churchill’s polar bear jail, which is the local signal that there is enough sea ice for bears to leave shore. As I reported two weeks ago, release of jailed bears happened this year on 10 November. And as I predicted in that post, by waiting so long after that event to post his map, Derocher can make it seem to his naive followers on Twitter that the bears are just starting to leave now (the last map he posted was on 11 November, when none of his bears had moved). He reinforces this by calling WH freeze-up “late”, when by all objective measures (including local informants reporting bears on the ice) it was as early as it had been in the 1980s (Castro de la Guardia et al. 2017).
Recall that fall is the second-most important feeding season for polar bears, due to the fact that seals are strongly attracted to newly-forming sea ice. It’s their chance to regain some or all of the weight lost over the summer, before the long winter fast begins (while bears indeed hunt when they can, they are not often successful during the depths of the Arctic winter: most bears are at their lowest weight by March).Continue reading