By Ro Bury
I thought it was a small bear perched on the ice shelf that jutted into the Little Spokane River. It was dark brown and black in color and moved slowly across the ice and up onto the shore. Since we had never seen beavers (or evidence of beavers) on our property in the 25 years we have lived here, it was a surprise when the view through the binoculars showed a broad, flat tail attached to the back of the animal. Beavers are America’s largest rodent, and the adults are up to 4 feet long and 60 pounds. This guy was at the extreme end!
Further investigation revealed a well concealed lodge just upstream from the sighting. Most lodges are made up of sticks and mud and can be up to 10 feet tall. They usually have 1 large, central chamber and 1 or 2 entrances. The floor of the chamber is a little above the water line and covered with wood chips to absorb moisture. The chamber is vented for fresh air. Some beavers build burrows in the banks of rivers (“bank dens”) and may or may not build lodges over them. “Our” beavers had a “bank den” with a small lodge over the top. One family may have several lodges or dens at any given time.
We had periodic sightings over the next few years; usually the beavers were swimming down the river. There were various sizes, and we assumed we were looking at the male and female and 2 year olds most of the time.
In the spring of about 2010, the river was exceptionally high and running fast. We saw that the lodge was halfway underwater and worried about the beaver family. After the water levels dropped, we noticed a fairly large tree coming down the river. As we got closer, we saw there was an adult beaver on either end of the tree, deftly navigating it around the bend and away from the shoreline where it might get hung up. As they rounded the last bend, we were happy to see they were apparently busy building a new lodge.
In 2012, my husband and I were standing near the shoreline near a large bull pine when we noticed a 12 inch baby beaver come onshore. It sniffed its way toward us, apparently looking for grass shoots. The little guy didn’t notice us until he was directly in front of us. He stood up on his back legs, sniffed the air, looked at us and jumped about 20 feet before running back into the river!
In 2013, a large piece of an old cottonwood tree fell in our back yard. It was very cold and close to the first snowfall so we decided to leave it there for the winter. All winter long, the beavers visited the main trunk and the broken branches. We weren’t sure if they were taking parts back to the lodge or what. This spring, it was obvious they had been nibbling on the bark and the cambium (or soft tissue that grows under the bark). We know they also eat roots, buds, grasses and other water plants. They have ingenious ways of hauling small branches and trees and storing them in or near their dens for use during the winter.
We are so fortunate to live on the river where we can observe the wildlife up close. The beavers are at the very top of our favorite river animals!
OTHER INTERESTING BEAVER FACTS:
• Beavers mate for life (but a replacement will be found if one dies).
• Gestation lasts a mere 3 months. The kits can swim within 24 hours of birth and stay with the parents for 2 years.
• They can live up to 20 years.
• Beavers live in colonies made up of the breeding male, female and kits up to 2 years old.
• They coat their fur with castoreum, an oily secretion from the scent glands.
• There is a thick layer of fat under the skin that keeps the beavers warm underwater.
• The long upper and lower incisor teeth are used to cut into trees and woody vegetation. The teeth grow throughout the beaver’s life.
• Beavers live throughout North America except Florida, the desert Southwest, Mexico and the Northern most parts of Canada.
• Positive impacts on the environment include creation of new wetlands that slow erosion, raise the water table and help purify the water.
• Negative effects include silt build-up behind dams that slow the flow of water and can cause low lying areas to flood.
For further information, see the Washington Department of Fish & Wildlife website. “Living with Wildlife” offers some ideas on how to install barriers on trees, beaver-resistant plants and repellents.