Lemmings as climate-change canaries


photo: E. Leslie, via New Scientist

As Science News reports, drawing on a paper in the Nov 6 Nature (paid subscription required), climate change -- in particular a lack of the fluffy snowpack that lemmings depend on as cover for ground-level foraging -- appears to be putting the hurt on lemming populations in Norway. This crimp in their diet has left some to starve to death and may be the reason that a particular area in south-central Norway has not seen one of the famous lemming population booms since 1994.

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 his colleagues suggest that climate change has interrupted the normal boom-and-bust cycle of lemming populations.

The effect is spreading to the rest of the ecosystem:

With the recent lack of population booms among lemmings, predators such as arctic foxes and snowy owls have turned their attention to other prey, including ground-nesting birds such as ptarmigan and grouse, whose numbers have declined.

Hat tip to Boing Boing.

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