Zombie Polar Bears
/ Post by Dr. Andrew Derocher of Polar Bears International
Summer vacation for the Hudson Bay polar bears ended a bit earlier this year. While early termination of a holiday for us is a tad depressing, for the bears the return to the sea ice is likely a happy event (if one cared to put emotions to polar bear movement patterns). Of course, the ringed seals and bearded seals out in the bay may not be quite as happy to see their big white neighbors back.
The bears were back on the ice by early December although they still haven’t moved very far offshore (see map below). The reason for the near shore locations is tied to a somewhat slower freeze-up in the southwestern parts of Hudson Bay (see map). Some of the bears from 2011 are pregnant and have stayed on land and won’t head to the ice until February or March.
While 2012 wasn’t a particularly tough year for the bears with a bit later break-up and a reasonable freeze-up, it still isn’t anywhere near the 1980s for ice conditions, and this year is still well below normal (see bar graph). For the Arctic as whole, November had the 3rd lowest amount of sea ice since satellite records began. With a 4.8% decline per decade in November sea ice, the trend is clear.
The biggest concern for the bears of Churchill is the remarkably low recruitment rate: we’re seeing very few females with cubs and yearlings. Any population that doesn’t produce enough new animals is essentially a zombie population. Over time, the population will age and reproduction will continue to decline. Unlike “real zombies,” a zombie polar bear population will die. This of course assumes that we don’t see a catastrophically early ice melt combined with a greatly delayed freeze-up that could devastate a population in a single year! When we add in the increased harvest of polar bears in Nunavut (which approved a quota increase from 8 to 24 bears in 2012), the pressures on the Western Hudson Bay population are intense.
Is there hope? Without doubt. Time remains to change the future. At this time of year, one might think about the “Ghost of Polar Bears Past,” the “Ghost of Polar Bears Present,” and the “Ghost of Polar Bears Yet to Come.” It’s the last two we’re most concerned about. The Doha 2012 U.N. Climate Change Conference shows that there are still efforts to deal with global warming but a lot more needs to be done. For example, Canada was recently challenged to explain its weak polar bear conservation after a challenge from the Center for Biological Diversity under environmental provisions of the North American Free Trade Agreement. Such efforts keep polar bears on the forefront of the climate change.
However, we really need a grassroots movement to change what governments are doing. Burning coal, exporting coal to be used in developing countries, the tar sands, and other such environmental catastrophes need to be reined in. We have the technology but business leaders need appropriate incentives from government. Governments need to hear from the people.
Polar Bears International is helping in so many ways. Foremost, it has helped make the association between global warming and the threat to polar bears understood by all but the most recalcitrant deniers. Understanding that there is a problem is the first step; action is the second and most important step. Changing things will be a process, not an event, and I remain optimistic.
