Beavers

Leave it to Beaver(s)

by

Kathy Webster

Who remembers the TV show, “Leave it to Beaver?”" It was a 50’s show about the perfect youngest son. Like the Cleavers, beavers make the perfect neighbor in so many ways.

Beavers are a keystone species, which is “a species that has a disproportionately large influence on the species around it relative to its abundance”. In other words, one beaver family creates habitat for a multitude of other species that rely on this habitat for their survival. Beaver ponds and the surrounding wetlands are so important that they are afforded some legal protections under the Clean Water Act. “Wetlands are protected from filling and development under section 404 of the Clean Water Act (CWA). The primary goal of the CWA is to “regulate waters of the United States including wetlands from discharge of dredge or fill materials”.

Beavers and beaver ponds increase biodiversity. Beavers are known as “nature’s best ecosystem engineers”. Beavers build dams which in turn create wetlands which attract insects, fish, birds, amphibians, reptiles, and even some mammals. Beavers build homes or “lodges”, which provide homes for other animals such as muskrats, mink, raccoons, and otters. Some birds choose to nest on top of the lodges. The bases of the lodges provide refuge for small fish, frogs, reptiles, and amphibians. The beaver ponds also provide refuge for some migrating animals and birds. Another way beavers are “engineers” is by felling trees. Beavers only cut trees in order to build their lodge. Once the lodge is built, they only eat shrubs and the surrounding vegetation, such as willows or young cottonwood. In winter, the beavers store and eat cambium to survive.

Beaver ponds help improve water quality. Beaver ponds filter out and store nutrients and pollutants. Beaver ponds also store sediment and if left in place, the sediment will eventually turn the pond into a marshy meadow. Beavers use the mud and sediment on the bottom of their ponds to build and restore their dams and lodges.

Beavers are our allies and neighbors in climate change adaptation. Do you want to mitigate floods? There’s a beaver for that! Want to capture more water for agriculture? There’s a beaver for that! Worried about dry stream beds or erosion? There’s a beaver for that! Do you need wetter soils to provide a fire break to protect against wildfires. There’s a beaver for that! Ben Goldfarb writes in his book, Eager: The Surprising Secret Life of Beavers and Why They Matter: “Beavers, the animal that doubles as an ecosystem, are ecological and hydrological Swiss Army knives, capable of tackling any landscape-scale problem you might confront”.

There are other ways beavers help reduce the impacts of climate change. A recent study showed that water temperatures downstream of beaver ponds were 4.5 degrees F. lower than upstream. As air and water temperatures rise, this recharging of ground water downstream could make a difference for some species. Beaver ponds store carbon, but the greatest way that beavers help humans adapt to climate change is by storing water and improving hydrologic conditions. By increasing water storage on the surface, the water filters down into the water table and recharges groundwater, helping to keep some streams running that might otherwise go dry in the summer.

Beavers and beaver ponds are biodiversity “hotspots”. If you are fortunate enough to have a beaver family for a neighbor, please welcome them to the neighborhood, respect their unique and specialized place in the ecosystem, and practice coexistence. According to Aaron Hall, Senior Aquatic Ecologist with the non-profit organization, Defenders of Wildlife, “Beavers are dam important!”.