Warmer winter temperatures are altering the snowpack, squelching the rodents’ population booms
Packs of Norway lemmings aren’t necessarily headed off a cliff, but climate change in a part of that country certainly seems to have stifled population spikes of the oft-prolific creature in recent decades.
Lemmings are famed for their population booms: Occasionally, across small regions, their numbers can briefly swell a hundredfold. Dramatic increases of the rodents typically occur every three to five years, says Nils Christian Stenseth, an evolutionary ecologist at the University of Oslo in Norway.
But at one site in south-central Norway, lemming populations haven’t spiked in such a way since 1994, he notes. In the Nov. 6 Nature, Stenseth and