From Reuters:
NORWAY: November 6, 2008OSLO - Lemming numbers are dwindling in Norway because of climate change, ending a historic cycle of population booms and busts that inspired a myth of mass suicides by the rodents, scientists said on Wednesday.
Fewer lemmings -- small brown, black or yellowish mammals -- in the mountains of south Norway meant predators such as the Arctic fox were forced to eat other prey including grouse and ptarmigan birds.
"The lemming population is falling and the peaks are disappearing," said Nils Stenseth of Oslo University, one of the authors of the report published in the journal Nature and written with colleagues in Norway and France.
He told Reuters it was the first study to link lemming numbers and disruptions to snowfall caused by global warming. The study of lemmings since 1970 showed the last population boom was in 1994, ending a pattern of spikes every 3-5 years.
Female lemmings can have litters of up to 12 young three times a year and the population can rocket if they are able to live sheltered from predators in early spring in gaps between powdery snow and the ground where they eat moss and other plants.
But warmer temperatures in recent years meant snow was wetter, often turning hard and icy. That made it more difficult for rodents to hide and reach food. (((Bad news for those who invested in toxic lemming real-estate investments.)))
"A relatively small effect on one particular species is having a broad effect on the system," Stenseth said. In years with a lemming population boom, predators such as Arctic foxes or snowy owls used to get a valuable boost....