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Global Animal Guide
North American beaver swimming with stick in mouth near a dam

North American Beaver

Castor canadensis

Photo: Steve from Washington, DC, USA · CC BY-SA 2.0 · source · credits

Quick answer

The North American beaver is a large rodent that fells trees and builds dams and lodges, creating wetlands that benefit fish, birds, and other wildlife. Adults weigh 16–32 kg (35–70 lb), have webbed feet and a flat tail, and can stay underwater for up to 15 minutes.

Top questions about the North American Beaver

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Also available in Español (Castor norteamericano)

North American Beaver facts at a glance

  • Weight 25 kg
  • Length 1 m
  • Top speed 55 km/h
  • Lifespan 20 years
Key facts about the North American Beaver
Scientific name Castor canadensis
Diet Herbivore — bark, twigs, aquatic plants, and roots
Habitat Rivers, lakes, and ponds across North America
Lifespan 10–20 years in the wild
Weight 16–32 kg (35–70 lb)
Top speed Up to 55 km/h (34 mph) swimming; clumsy on land
Conservation status Least Concern (IUCN)
Scientific classification
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Rodentia
Family Castoridae
Genus Castor

Where it lives

The north american beaver (Castor canadensis) is native to Rivers, lakes, and ponds across Canada, the United States, and northern Mexico; reintroduced to parts of Europe where the Eurasian beaver also occurs. — recorded across North America in this guide’s range summary.

Native range (approximate)

For occurrence records, see GBIF species search and sources below.

How big is a north american beaver?

An adult north american beaver measures 1 m long — about 58% of the height of an average adult person (1.73 m) — and weighs around 25 kg, about 36% of an average adult’s body weight (70 kg).

Length vs an average adult’s height (to scale)

Average adult (height)1.73 m
North American Beaver (length)1 m

What is a group of north american beavers called?

Group name (collective noun)

A group of North American Beavers is called a colony.

Baby name

A baby North American Beaver is called a kit.

Explore more animal collective nouns and baby animal names .

Dam building

Beavers cut trees with powerful incisors and weave branches into dams that raise water levels, protecting lodge entrances and creating ponds. These wetlands filter water, reduce flooding downstream, and provide habitat for hundreds of species — beavers are considered ecosystem engineers.

Lodges and family life

Beaver families live in dome-shaped lodges with underwater entrances. Kits are born in spring and stay with parents for up to two years, helping maintain dams and learn construction skills. Castoreum from scent glands marks territory.

Recovery from trapping

Beavers were trapped nearly to extinction for fur hats in the 1800s but rebounded after protection and reintroduction. Today they are Least Concern, though conflicts with landowners over flooded roads and timber prompt relocation or flow-device management in many states.

Keystone role

By slowing water and creating ponds, beavers increase biodiversity, store carbon in sediments, and improve drought resilience. Reintroduction projects in the UK and Europe aim to restore these benefits after centuries of local extinction.

Dig deeper into the North American Beaver

Explore the North American Beaver

Did you know? North American Beaver facts

  • The North American beaver is a large rodent that fells trees and builds dams and lodges, creating wetlands that benefit fish, birds, and other wildlife.
  • Dams raise water around lodge entrances, making predators harder to reach and giving beavers safe access to food stores in winter.
  • Up to about 15 minutes underwater, aided by transparent eyelids and valves that close ears and nostrils.
  • Yes — beavers are the second-largest rodents after capybaras, in the family Castoridae.
  • No. Beavers are herbivores that eat bark, twigs, and aquatic plants. They do not hunt fish.
  • Conservation: Least Concern (IUCN).

Diet & feeding

North American Beaver feeds primarily as a herbivore — bark, twigs, aquatic plants, and roots. Beavers cut trees with powerful incisors and weave branches into dams that raise water levels, protecting lodge entrances and creating ponds. These wetlands filter water, reduce flooding downstream, and provide habitat for hu

Adaptations

  • Beavers cut trees with powerful incisors and weave branches into dams that raise water levels, protecting lodge entrances and creating ponds. These wetlands filter water, reduce flooding downstream, and provide habitat for hundreds of species — beavers are considered ecosystem engineers.
  • Beaver families live in dome-shaped lodges with underwater entrances. Kits are born in spring and stay with parents for up to two years, helping maintain dams and learn construction skills. Castoreum from scent glands marks territory.

Behaviour & ecology

  • Beavers cut trees with powerful incisors and weave branches into dams that raise water levels, protecting lodge entrances and creating ponds. These wetlands filter water, reduce flooding downstream, and provide habitat for hundreds of species — beavers are considered ecosystem engineers.
  • Beaver families live in dome-shaped lodges with underwater entrances. Kits are born in spring and stay with parents for up to two years, helping maintain dams and learn construction skills. Castoreum from scent glands marks territory.
  • Beavers were trapped nearly to extinction for fur hats in the 1800s but rebounded after protection and reintroduction. Today they are Least Concern, though conflicts with landowners over flooded roads and timber prompt relocation or flow-device management in many states.

Communication

  • North American Beaver uses scent, posture, and vocal signals to mark territory and coordinate social behaviour.
  • Communication intensity often peaks during breeding seasons and territorial disputes.

Habitat & range

Rivers, lakes, and ponds across North America

Ecological role

North American Beaver shapes vegetation through grazing or browsing and serves as prey for larger predators where ranges overlap.

Conservation status of the North American Beaver

Least Concern IUCN Red List category

The north american beaver (Castor canadensis) is listed as Least Concern on the IUCN Red List. Least Concern (LC) is the IUCN's lowest-risk category, assigned to widespread, abundant species that have been evaluated and found not to be threatened. It does not mean a species faces no pressures — only that it is not currently at risk of extinction.

The north american beaver (Castor canadensis) is assessed on the IUCN Red List. Look up on the IUCN Red List .

Frequently asked questions about the North American Beaver

Why do beavers build dams?

Dams raise water around lodge entrances, making predators harder to reach and giving beavers safe access to food stores in winter.

How long can beavers hold their breath?

Up to about 15 minutes underwater, aided by transparent eyelids and valves that close ears and nostrils.

Are beavers rodents?

Yes — beavers are the second-largest rodents after capybaras, in the family Castoridae.

Do beavers eat fish?

No. Beavers are herbivores that eat bark, twigs, and aquatic plants. They do not hunt fish.

Are beavers good for the environment?

Yes. Beaver wetlands increase biodiversity, improve water quality, and can reduce downstream flooding — reasons for active reintroduction in Europe.

What is a group of north american beavers called?

A group of North American Beavers is called a colony.

What is a baby north american beaver called?

A baby North American Beaver is called a kit.

Sources & references

This guide is compiled and reviewed against established zoological and conservation references. Key sources for the North American Beaver:

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