Beavers as a Keystone Species_02

Beavers are probably best known for their dam-building abilities, using their long chisel-like incisors to chew down trees for dam-building material. Along with other vegetation, rocks, and mud, they construct dams to block off waterways to create wetlands. It is these wetlands that become important to other organisms that rely on them for survival.

So what does the beaver do for the ecosystem and what would happen if it were removed? One obvious factor is they create wetlands that attract and become home to many organisms, such as species of plants, frogs, and birds. Bird eggs become food for reptiles and rodents. Amphibians become food for a host of creatures, such as owls, opossum, shrews, and bass. The newly created wetland provides a home to aquatic plants that feed just about every herbivore native to wetlands.

Even waterfowl benefit from these new wetlands as they are able to use the cut-down trees for nesting material. In the case of the waterfowl and beaver relationship, one species benefits, while the other species neither benefits nor is harmed. This symbiotic relationship is called commensalism.

Even grizzly bears rely on the work of beavers because the dams regulate water flow and filter sediment, making the waterways more conducive for some species of fish, such as trout and salmon. It is thought the population of trout and salmon would suffer a massive decrease if not for the work of the beaver.

While it is sad to see any species struggle to maintain its foothold in a region, it is the keystone species that scientists watch the closest. If an ecosystem loses one species, its niche can be filled by another species, but this is not true of the keystones. Like the game of Jenga, when a keystone is removed, the whole tower may collapse leading to a catastrophic loss. While man may take issue with beavers turning their otherwise dry land into a wetland, it may be a small price to pay considering the advantages provided to the overall ecosystem on Earth.