With global warming and melting ice, it isn’t easy being a polar bear anymore. Some studies
have predicted that polar bears could very well be extinct by the end
of the century. The good news is not all researchers think the bears are
absolutely doomed. Scientists at the American Museum of Natural History
(AMNH) have published a new paper indicating that things might not be
as bleak for polar bears as their peers expect.
To understand the reason for the researchers’ cautious optimism, we must first understand the factors that are threatening the polar bear’s existence.
Polar bears consume a diet of mainly young seals. In order to hunt
these seals, polar bears need to rest atop sea ice – the same ice that
is increasingly melting for most of the year thanks to climate change.
In another 50 years, experts expect that the Arctic will be too warm for
sea ice to form for half of the year, leaving polar bears without a
reliable food source and in serious danger of starvation.
As it turns out, alternative food sources for the polar bears aren’t completely out of the question.
For as long as biologists have tracked the animals, they’ve recorded
instances of polar bears eating animals found on land like caribou and
snow geese – as well as the snow geese’s eggs. “Polar bears are
opportunists,” stated Robert Rockwell, a researcher with AMNH.
Can
polar bears actually survive off these alternative food sources for
long periods of time? To figure this out, researchers calculated the
nutrients that a caribou and snow geese diet would provide. They found
that even adult male polar bears would be able to obtain more calories
than they would burn in hunting these meals. Moreover, the food would
provide the sustenance necessary to avoid starvation during the summer
months.
Unfortunately, not all polar bears have demonstrated a
tendency to seek prey on land. That said, the researchers expect that
necessity would push more polar bears to hunt on land to avoid
starvation. They also expect that the bears could learn from their
fellow bears how to hunt on land until the practice becomes second
nature.
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