The beaver holds the title for being the largest rodent in North America with adults measuring 35 to 46 inches long, including their signature wide and flat tail. They can weigh up to 110 pounds, but usually they weigh in at 45 to 60 pounds. Their tail is unique from other rodents because it is nearly round, covered with leathery scales and has sparse, coarse hair. Beavers use it like a boat rudder as they swim and they use it for balance when they're on land gnawing on sticks. You may not know that beavers also slap their tail on the water, echoing throughout the pond, as a warning signal that danger is nearby. They have huge back feet with five webbed toes to help them navigate the waters. Their front feet are tiny compared to the back to help them hold sticks for gnawing, and to help them carry stones and sticks to construct their dams. Their fur is long and coarse and ranges in color from a light pale yellow to black. You probably know that beavers have large, sharp, front teeth but did you know that their ears and nostrils are small so they can be closed when the beaver swims underwater?
It is common to see bark stripped off of tree trunks near the ground in beaver territory. A beaver's favorite meal is twigs from aspens, poplars, alders and for a side dish water grasses, fleshy roots, and water lilies. In the fall, beavers cache (store) branches and logs in the water, near a lodge or bank burrow so it is easy to get at in the winter. Beavers will go ashore in the winter as long as they can break through the ice at the pond's edge.
Beavers are really the only wildlife in Wisconsin that will remodel their environment to suit their needs. They dam up small streams to create a pond where they then build a lodge. Around the pond you'll find canals and runways used to transport building materials and food back to the pond. Beaver dams can get quite big, as big as 15-feet wide and 5 feet high. They are built of sticks and mud. This engineering creates widespread flooding of woodlands and farmland which benefits other wildlife species like otter, mink, muskrats, deer, bear, waterfowl, waterbirds and grouse. On the other hand, beaver dams block trout from migrating upstream and keep them from reproducing and can plug man-made structures like culverts causing flooding on roads, railroad tracks and farm fields.
Beaver populations in Wisconsin haven't always been healthy. They were commonly found in Wisconsin before European settlement, but by 1900 logging and fur trapping almost caused them to become extinct. Beavers were then protected from trapping. Wildlife managers restocked the populations until their numbers recovered.
Today, regulated trapping allows wildlife professionals to manage beaver populations in Wisconsin. Look for beaver sign like gnawed trees, and their signature tracks near the banks of ponds, wetlands, and other wet areas.