Prelims: Current events of national and international importance | Species
Why in News?
Recent research from Canada, US, and UK shows beaver‑made wetlands retain water, keep vegetation green in droughts, and help curb wildfire spread.
- Beavers are large, stout, semiaquatic rodents.
- Two species – Eurasian and North American beavers.
- The North American beaver is native to the United States, Canada, and northern Mexico, and inhabits rivers and wetlands.
- Known for – Building dams, which makes them important ecosystem engineers and keystone species.

- Historical Decline – In the 19th century, beavers were extensively trapped for the European fur trade.
- Their population declined from tens of millions to approximately 100,000 by the early 1900s.
- Conservation & Recovery – Reintroduction, ecological recognition, and human‑beaver coexistence efforts have enabled population recovery, making beavers no longer at risk of extinction.

- Ecological Role
- Beaver dams expand available habitat, store food, and provide protection from predators.
- By slowing water flow, beaver dams help prevent erosion and flooding, and create wetlands.
- Wetlands created by beavers accumulate nutrient-rich sediment, which supports plant growth, provides wildlife habitat, and improves water quality.
- Beaver activity sequesters approximately 470,000 tons of carbon annually, contributing to climate mitigation.
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Research Findings
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Canada – Elk Island National Park
- A 54-year aerial photo study conducted in 2008.
- Beaver lodges accounted for over 80% of the variation in open-water area.
- During the 2002 drought, beaver wetlands contained nine times more open water than areas without beavers.
Britain – Devon
- Within a beaver enclosure, thirteen dams stored approximately one million litres of additional water.
- The dams slowed stormwater flows and gradually released water during dry periods.
- In wild territories, wetlands retained over twenty-four million litres of water.
Western United States
- A 2020 study examined five wildfires.
- Streamside vegetation in beaver-dammed areas was three times less affected than in areas without beavers.
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Reference
Down to Earth | How Beavers Can Help Create Firebreaks