Beavers, The Ecosystem Engineers and Keystone Species

Beavers

Beavers are semiaquatic amphibious rodents of the Northern Hemisphere.
They are the largest rodents in North America and Eurasia.
They are the second largest rodents worldwide.
Distribution: They are native to North America, Europe, and Asia.
Habitat: Streams, rivers, marshes, and ponds and on the shorelines of large lakes.
Conservation Status:
- American Beaver (Castor canadensis): IUCN: Least Concern
- Eurasian Beaver (Castor fiber): IUCN: Least Concern

Beavers build dams and lodges using tree branches, vegetation, rocks and mud.
Dams restrict water flow, and lodges serve as shelters.
Their infrastructure creates wetlands used by many other species, and because of their effect on other organisms in the ecosystem, beavers are considered keystone species.

Ecologists often refer to beavers as “ecosystem engineers” because of their ability to alter the landscapes in which they live.

Keystone Species: It is a species whose addition to or loss from an ecosystem leads to significant changes in the occurrence of at least one other species.
- If keystone species are lost, it will result in the degradation of the whole ecosystem.
- Considered important in determining the presence of many other species in that ecosystem.
- Eg: Top level predators