10:16 AM EST February 04, 2003
The Associated Press
STATE COLLEGE, Pa.
Groundhogs that emerge from their dens in early February are probably looking for sweethearts, not shadows, a researcher says. And what's more, the girl groundhogs invite the boys in for a visit.
The rodent ritual - whimsically marked each Feb. 2 as Groundhog Day - seems to be part of the mating ritual "to see which females are available and where they are," said Stam Zervanos, an associate professor of biology at Pennylvania State University's campus in Reading.
Their scouting done, the groundhogs then return to hibernating until the March mating season, he said.
The appearances are the heart of modern Groundhog Day celebrations, which evolved from a German superstition that if such an animal sees its shadow on the Christian holiday of Candlemas, then a long winter is in store.
"What's happening, I'm pretty confident, is that they're getting together, getting ready for mating that's going to come later," Zervanos said.
During the last four years, Zervanos observed about 30 groundhogs that live on a university-owned farm near Penn State's Berks-Lehigh Valley College.
Most went into hibernation in early November, emerging in early February. Males tended to explore their territory, often visiting the dens of area females, while females tended to stay near their den openings.
Although a male might stay with a female for as long as two days, they don't appear to mate then, Zervanos said. Instead, the visits might be a necessary ritual of courtship for the normally anti-social creatures, he said.
It wasn't clear whether groundhogs later mate with the same partners they visit during February.
Males from similar species are also known to appear at females' dens, but the females usually stay inside, "so there's no interaction," said Theresa M. Lee, a University of Michigan professor who has studied rodent hibernation.
"That's quite unique," she said.
On the Net:
Penn State Berks-Lehigh Valley College: http://www.bk.psu.edu