Polar Bears Drowning As Globe Warms

An anonymous reader writes "The Times Online is reporting on disturbing findings from the arctic. Polar bears appear to be drowning when they attempt long sea crossings as a result of receding summer ice." From the article: "New evidence from field researchers working for the World Wildlife Fund in Yakutia, on the northeast coast of Russia, has also shown the region's first evidence of cannibalism among bears competing for food supplies ... As the ice pack retreats north in the summer between June and October, the bears must travel between ice floes to continue hunting in areas such as the shallow water of the continental shelf off the Alaskan coast -- one of the most food-rich areas in the Arctic. However, last summer the ice cap receded about 200 miles further north than the average of two decades ago, forcing the bears to undertake far longer voyages between floes. "

Comments

yes . . . if that was the only thing in the world

[Phil Urich]

Not extinction and re-evolution, but swings in population levels can be quite severe even in 'undisturbed' nature.


Like another poster mentioned, unless this gets much, much worse natural selection will simply start choosing bears better at swimming, or that find an alternate method for moving.

Interesting thing about evolution: it's not a perfect upwards slope. Indeed, in many ways biodiversity has been on a downwards slope for long before humans came onto the scene. Furthermore, consider that introducing a new way for animals to die doesn't happen in a vacuum; this is one of many examples of shrinking habitats and increasingly hostile situations that animals in the world (including humans, but we're good at changing our immediate environment to offset the overall environment) are finding themselves in.

To go back to what I was nudging towards initially, though: 'natural selection' is not another name for 'all-powerful god', that is to say, just because a new method is needed doesn't mean that this 'natural selection' thing will magically provide it; natural selection is just trimming combined with chaos, there are severe limits to what it can do, and I can't think of many methods that the bears could use other than swimming (I do realize that you said "unless this gets much, much worse", but really, there aren't that many alternate methods of moving, it's not like they'll suddenly develop wings). And anyways, I would think that after so much time, Polar Bears as a species would be pretty damn good at swimming. I doubt it's merely the few weaker ones that are drowning. The article notes that ALL the bears are being forced to swim further from the shore, and some of the deaths noted were from storms that arose; so whether they're good swimmers or not isn't even going to make that much of a difference, it's an extra bonus to the death rate period.

Hmm, in some ways I'm sortof making a straw man out of your argument. But really now, just think about it for a moment. As you mentioned, population levels can swing quite dramatically in rather 'natural' situations, yes. Now say that one of those swings happens for some random reason, combined with the problems noted in the article. It's not that hard to imagine entire populations of polar bears dipping dangerously low. The article mentions increases in the rate of cannibalism due to the lack of food sources, so for many populations there may be a tipping point that would create a downward spiral. Consider also that this is just one of many examples of the effect of humans on the environment that hurts wild populations, so I might agree with you if this was all that was going on in the world (ie. if the only thing that polar bears had to deal with was having to swim further), but it's the combination of many harmful factors that puts species at risk.

Plus, just from an empathic perspective, I'm not exactly going "hurrah! animals are dieing!". I'd rather they, umm, not die when they shouldn't be.

Re:white bears swim to "find food". Black bears lo

[ShadowBlasko]

I know this was a joke, but you *are* aware that Polar Bears are actually black right?

Black with white (dense) hollow hair, that acts similar to millions of small fiber optic pieces to channel light down to the black skin, where it is more efficiently used.

So, more accurately think of an old black man with white hair. I know a few of those, and they are pretty cool!