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story.lead_photo.caption Groundhogs — also known as whistlepigs, woodchucks, thickwood badgers and land-beavers — play an important role in the ecosystem, naturalist Jordanya Raos said. Photo by Associated Press / Fulton Sun.

Groundhogs, woodchucks, whistle-pigs — whatever they're called, seeing one of these roly-poly rodents always puts a smile on naturalist Jordanya Raos' face.

Just days after America's most famous groundhog, Punxsutawney Phil, predicted six more weeks of winter, Raos gave a virtual presentation on the animals. Raos works at the Missouri Department of Conservation's Springfield Conservation Nature Center.

Groundhogs — or Marmota monax, to give them their scientific name — are among the United States' largest rodents. They're also, technically, the U.S.'s largest squirrel — they can even scramble up a tree to escape predators or find food. However, they dig long, multi-branched burrows in which to dwell.

"Pay attention to their body shape," Raos said. "It's short and bulky."

With their powerful shoulders and claws, groundhogs can move hundreds of pounds of dirt while tunneling up to 60 feet long and 3-6 feet deep. Most burrows have a front entrance, a rear spy-hole and a toilet tunnel separate from the sleeping area.

"They are clean animals — no animals want to be around in their own filth," Raos said.

Female groundhogs dig a nursery at the deepest point of their network of tunnels. Groundhogs are solitary creatures and sometimes battle for territory. They mate in spring, and male groundhogs don't typically stick around to raise the young.

However, Raos noted, there's still a lot scientists don't know about the social lives of groundhogs.

"They're very private, they live underground and they don't like being around researchers, so they're hard to study," she said.

An alarmed groundhog gives a piercing whistle to warn other groundhogs in the area of danger — hence the nickname "whistlepig."

Groundhog tunnels are often dug beneath grassy open fields, along the sides of highways, in rock-dotted hillsides or in people's yards. Groundhogs are common throughout the eastern United States, including Missouri. Out west live their cousin, the yellow-bellied marmot. Because they share human's preferences for flat, grassy areas, groundhogs often live in the same places people do, and they're happy to use an abandoned pipe or culvert as part of a burrow.

Like other rodents, groundhogs have long front incisors. As herbivores, they also have molars for chewing.

"They're food-obsessed," Raos said. "They eat over a pound of food a day. Imagine that for an animal that's 4-14 pounds, max."

Groundhogs munch on wild grasses, weeds, berries and other fruit, and human agricultural crops, plus the occasional insect. They particularly enjoy pawpaws, which are dense in calories.

"Food is food to them," Raos said.

Groundhogs gorge all spring, summer and fall to fatten up for the winter, which they spend hibernating in their burrows. They wake up when the weather warms for spring — or, if their name is Punxsutawney Phil, when they're awakened to give a weather forecast on Groundhog Day. Stormfax Almanac, which has tracked Phil's predictions since 1887, found Phil is right only 39 percent of the time.

"Can groundhogs predict the weather? Probably not," Raos said.

Because groundhogs enjoy nibbling on peoples' gardens and living in peoples' yards, the often come into conflict with humans, Raos said. But because groundhogs need time to establish burrows and feed up for winter, evicting them during the wrong time of the year can be a death sentence.

Raos recommends being proactive and making efforts to exclude groundhogs by fencing in gardens — extending the fence underground so it can't be easily burrowed under — and covering gaps in your foundation with hardware cloth. Once a groundhog has established a burrow, there are still a few ways to encourage it to move out without hurting it.

"You can do things like make it uncomfortable," Raos said.

That might include repeatedly filling one end of the burrow with rocks, or playing loud music at the burrow's entrance.

She recommends doing this during between late July and September, after young groundhogs have left the burrow.

Though they can inconvenience humans, groundhogs have an important role to play in the ecosystem, Raos pointed out.

As they dig, groundhogs aerate soil and encourage plant growth. Their abandoned burrows become homes for other animals that aren't as good at digging. And they provide an important food source for Missouri's larger predators, such as bobcats, coyotes and hawks.

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