Yellow-bellied marmots are taking to global warming just fine—so far. A Nature study of the hibernating Rocky Mountain-dwellers found that over the last 30-plus years, the marmots have grown both in girth and in population, and the researchers think they know why.
Study author Arpat Ozgul says that the marmots have limited time to accomplish the things on their summertime agenda—namely, eating, mating, and giving birth before they crawl back into their seven- to eight-month hibernation.
But as the Colorado summers have grown longer, so too has the time the marmots have to do all of these things—and do them better. This extra preparation (and reproduction) time means that “they are more likely to succeed and survive,” said Ozgul [Scientific American].
Because of the extra time, marmots studied grew in average weight from approximately 6.8 pounds to 7.5. And since 2001 the marmot population has exploded, adding an average of 14 individuals each year; in the previous 25 years the population growth rate was only .56 per year.