I was asked recently if I knew the largest rodent in North America. My first thought was my great uncle Wally, who was known for his ability to gnaw his way through a casino-sized buffet and darn near qualified as a full load when he climbed into his half-ton pickup. But then I put my brain in gear and decided the answer instead must be the beaver.

And I was correct. In fact, the North American beaver is the third largest rodent in the world. Most of us know beavers as “nature’s engineers” —the first beaver I ever saw was on my father’s MIT ring, since the toothy fur-bearer is MIT’s mascot in honor of its engineering skills and its habits of industry.

They’re also fun to watch. While they are primarily nocturnal, it’s not uncommon to see them at either edge of the day. Beavers are vegetarians, but instead of finding them down at the local food co-op they favor small-diameter stems of hardwoods such as aspen, birch, and maple, typically within 100 feet or so of the stream or wetland they’ve chosen to dam up. They are remarkably adapted, sporting webbed hind feet and a flat tail that can be used as a rudder and paddle that earns them the description as “semi-aquatic”—think Michael Phelps, minus the illicit recreational activities.

Beavers also provide us with an opportunity to learn a critical lesson for our own survival—a lesson that we are in danger of ignoring. To feed and house themselves, beavers need a young hardwood forest near a stream or wetland. When they’ve felled and eaten the available stems near their lodge—or when humans do it for them—they must move on.

Author Jared Diamond makes a similar point about human beings in his book Collapse: How Societies Choose to Fail or Succeed. Diamond posits that historically, societies fail for at least one of eight reasons. Deforestation and habitat destruction top of a list that includes soil problems, water management problems, overhunting and overfishing, and overpopulation. Whether its trees, water, soil or wildlife, when societies overwhelm them, humans must, like the beaver, move on or collapse.

Presumably, one difference between humans and beavers is the element of choice. Presumably, we have the wherewithal to change our habits to sustain the resources and live on without moving on.

In fact, we are not currently making such a choice, as even in New Hampshire we continue to lose forests and important agricultural soils to development. I don’t know that we’ve yet identified where we might “move on”—Mars seems a tad chlly, even this time of year.

A few weekends ago, Malin Clyde, Coverts Project Coordinator at UNH Cooperative Extension, told the story of the North American beaver as part of a field trip along part of the newly-opened Sweet Trail in Durham and Newmarket. The Sweet Trail, named for Cyrus and Barbara (Bobbie) Sweet—is a four-mile walking trail from Longmarsh Road in Durham through lands conserved by the Great Bay Resource Protection Partnership (GBRPP) to the shore of Great Bay in Newmarket.

The GBRPP is a terrific example of the human community choosing to protect its habitat. Made up of variety of conservation groups, including The Nature Conservancy, Great Bay National Estuarine Research Reserve, NH Audubon and the Forest Society (among others), and working with local communities around Great Bay, the Partnership has permanently protected more than 5,000 acres. The waters of Great Bay are still in danger, but great strides have been made. The beavers are returning.

For more information about the Cy and Bobbie Sweet Trail, go to http://www.greatbaypartnership.org/mapsweet.html

Jack Savage is editor of Forest Notes magazine and vice-president for communications for the Society for the Protection of New Hampshire Forests. He can be reached at jsavage@forestsociety.org.