As a classic “keystone speciesc,” American beavers are among the most important native species found on our continent. These enormous animals comprise the second-largest rodent species on Earth, sometimes weighing in at 100 pounds or more, and an impact to match their size! Here are five ways beavers are good for an ecosystem.
1. Beavers improve water quality. A colony of beavers creates a dam that dramatically slows water current and allows water-purifying plants to thrive. They help protect freshwater ecosystems during droughts and increase the amount of water purified as it percolates into underground wells. Studies have found that in areas where livestock are raised, the presence of beavers can help to remove wastes like E. coli, nitrogen, phosphates, and strep.
2. Beavers help waterfowl raise their young. A beaver’s dam increases the amount of surface water in a wetland, multiplying the number of usable nest sites on a given piece of land. Beaver lodges are also among the safest and most viable places for trumpeter swans, Canada geese, and native ducks to raise their families. In Wyoming, one study concluded that the presence of beavers increases the number of water-birds by 7500%!
3. Beavers build natural nest boxes for birds and mammals. As humans have eliminated most of America’s old-growth forests, animals that depend on hollow trees are facing serious problems. Beavers help to address that! When their dams “drown” waterside trees, these trees quickly attract woodpeckers, which, in turn, create cavities where swallows, owls, flying squirrels, wood ducks, and kestrels can safely raise their young.
4. Beavers help trout and salmon. Trout and salmon in the United States are in big trouble, and ecologists suspect that their population declines could be a result of historic over-trapping of beavers. Beaver dams all over the continent provide winter habitats and safe spawning sites for cutthroat trout, bull trout, steelhead trout, Dolly Varden trout, brook trout, rainbow trout, and brown trout, coho salmon, Chinook salmon, and sockeye salmon. In some areas, the presence of beavers has been shown to increase these fishes’ populations tenfold. This impact helps feed humans, bears, and dozens of species of bird.
5. Beavers promote tree health and diversity. In the short-term, it may look like beavers harm forests, but long-term observations have shown the opposite. Many tree species regrow after being cut by beavers, and others depend on the rise, retreat, and flow of water from dams to spread and germinate their seeds. Beavers also increase the amount of surface water in a forest, which reduces the likelihood of catastrophic forest fires.
Beavers are one of the greatest treasures of the North American ecosystem. Without them, our entire continent’s ecology could collapse. Appreciate, and learn to coexist with, these incredible animals!