North American Beaver

Castor canadensis

North America's largest rodent, a busy builder whose dams make ponds that many other animals use.

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About the North American Beaver

North American beavers weigh 35 to 65 pounds and are 3 to 4 feet long, making them the largest rodents in North America. Their orange front teeth never stop growing, and iron in the enamel makes them strong. Beavers build dams of sticks, reeds and mud, which make slow-moving ponds. They eat leaves, woody stems and water plants, and they store branches underwater for winter. They can swim up to 6 miles per hour.^[1]

Quick facts

Scientific name: Castor canadensis^[1]
Size: 3 to 4 feet long and 1 to 1.5 feet tall.^[1]
Weight: 35 to 65 pounds.^[1]
Lifespan: Usually 10 to 12 years.^[1]
Diet: Herbivore. Leaves, woody stems and water plants, especially poplar, aspen, willow, birch and maple.^[1]
Habitat: Ponds, lakes, rivers, marshes, streams and nearby wetlands.^[1]
Where it lives: Most of North America.^[1]
Group life: Family groups. Mostly active at night.^[1]
Babies: Kits born in spring, weighing about 1 pound, with fur and open eyes.^[1]
Conservation status: Least Concern (IUCN Red List, assessed 2016).^[2]

Fun facts

A beaver's teeth can cut through a tree the size of a person's finger in one bite.^[1]
Beavers can stay underwater for up to 15 minutes.^[1]
Beavers comb their fur with a special split toenail on their back feet.^[1]

Vocabulary

dam: A wall built across moving water to hold it back.
lodge: A beaver's home, built of sticks and mud.
incisor: A sharp front tooth used for biting and cutting.
kit: A baby beaver.
least concern: A conservation label meaning a species is widespread and not at risk of dying out soon.

See it in person

Smithsonian's National ZooWashington, D.C. · American TrailSee this animal on the zoo's website ↗

These zoos had this animal when we gathered our information, but animals sometimes move. Check the zoo's website or contact the zoo before you visit.

Sources

[1] Smithsonian's National Zoo & Conservation Biology Institute. “Beaver.” https://nationalzoo.si.edu/animals/beaver (accessed 2026-10-08)
[2] IUCN Red List of Threatened Species. “Castor canadensis (North American Beaver).” https://www.iucnredlist.org/species/4003/22187946 (accessed 2026-10-08)