Greenland Lemmings’ Collapse Pushes Predators to Brink
by Virginia Morell
Lemmings don’t commit suicide by running blindly off cliffs—that’s a myth. But lemming populations in their Arctic tundra home can rise and fall dramatically in just a few short years. And the sudden collapse of a lemming population can mean hard times—or even extinction—for their predators, a new study shows.
Populations of collared lemmings—rotund rodents with small ears and short legs—are driven by predators and snow conditions. Their numbers follow a characteristic 4-year cycle, rising and falling with such regularity that the pattern has long fascinated scientists. But at the turn of the millennium, the lemming cycle collapsed in northeastern Greenland and has not recovered, most likely due to the increased warming of the Arctic, scientists report today in the Proceedings of the Royal Society B. And as lemming numbers have dwindled in the region, so have those of their predators; in fact, some populations are likely facing local extinction.
As a result, the authors note, the warming of the Arctic is not only causing some species to shift their ranges northward, but is even adversely affecting those that stay put. The discovery is one of the first to suggest how extensive the ecological effects of global warming are apt to be—with entire communities of animals and plants subject to change as the loss of a keystone species is felt throughout a food web…
(read more: Science NOW) (photo: N. M. Schmidt)