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Wildlife: Global Interference
Add the Arctic fox to the list of species around the world getting… well… outfoxed by global warming. According to a new study by wildlife biologists at the University of Alaska-Fairbanks, early ice melt is making it harder for these cold-loving canids to find food.
Researchers in 2005 tracked 14 foxes collared in northern Alaska during their first winter on their own. All perished, except for three, which spent the winter wandering the sea ice and feeding on seal carcasses left behind by polar bears. The others, which remained on the mainland, didn't make it to spring and likely died of starvation. "Our work pointed to the fact that the sea ice can be important during some years," says Nate Pamperin, a graduate student at the University of Alaska-Fairbanks, "but more work needs to be done over longer time periods to completely understand the importance of the ice from year to year."
The researchers determined that if future generations of Arctic foxes lose access to sea ice, fewer will survive winter, resulting in fewer pups born during some years.
A warming climate is wreaking the same havoc on caribou in Greenland, where fewer calves are being born and more of them are dying, according to a joint study by Pennsylvania State University and the University of Aarhus in Denmark. The problem: Peak food availability no longer corresponds to the timing of caribou births—and it's a predicted consequence of global warming.
For millennia, caribou have survived the long Arctic winter by digging deep in the snow to find lichens. As spring approaches, they migrate to calving grounds where budding willow and herbs are emerging. But when they arrive now, the plants are already past their peak.
"This factor is just one of the many related to climate change—such as thaw-freeze cycles, ice-crust formation and severe storms—that may make it difficult for caribou populations to persist at their former abundance," says Eric Post, an associate professor of biology at Penn State.
Meanwhile, beneath the ocean waves, there's another ecosystem out of whack: Jellyfish numbers are exploding. Their proliferation is raising alarm among ocean scientists, who blame a combination of overfishing, pollution and global warming.
Overfishing leaves more plankton available for jellyfish to eat. Fishing via gill net and long line also takes out many of the creature's main predators—tuna for example, along with those that get caught accidentally but in significant numbers, like sharks and sea turtles. When it comes to polluted waters, where oxygen and visibility are reduced, nothing fares better than jellyfish—passive filter feeders that can dine in the dark.
Add in a big dollop of warming ocean temperatures, which lengthens the creature's reproductive cycle, and it may be that the ocean—along with the Arctic—is reaching its boiling point.
Learn more about climate change and global warming.
