In the rigid social universe of Revenge of the Nerds-style 1980s movies, jocks beget jocks beget jocks, and the bespectacled geeks they push around beget generations of the same. But could being a victim of social bullying actually be inherited? A new study of DISCOVER’s favorite rodent, the marmot, shows that at least in the animal kingdom, the answer can be yes.
Daniel Blumstein and colleagues tracked yellow-bellied marmots that make their home in the Colorado Rockies for a five year period, from 2003 to 2008. For their study out in the Proceedings of the National Academy of Sciences, the team tracked the family relationships of the individual marmots, as well as who antagonized whom.
Marmots don’t have Facebook yet, but animals living among clusters of burrows in Colorado do interact enough for observers to plot networks with each marmot as a node. An exchange might be friendly, such as a marmot grooming a neighbor or settling down tranquilly nearby. Or a social interaction might go sour, with one marmot nipping or chasing another. “Marmots are grumpy with each other,” Blumstein says, but rarely cause serious injuries. [Science News]
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.