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American Beaver

Castor canadensis

Mammal · family Castoridae · order Rodentia

  1. G1
    Critically imperiled
  2. G2
    Imperiled
  3. G3
    Vulnerable
  4. G4
    Apparently secure
  5. G5
    Secure

NatureServe global rank G5: secure[2].

Updated October 30, 2026. Published by Humblebee.

American Beaver
Photo: Vlad Podvorny, CC BY 2.0, via Wikimedia Commons.
Endangered Species Act
Not listed[1]
NatureServe global rank
G5 Secure[2]
Native in
50 states[3]
Longest recorded life
23.4 years[4]

The American Beaver is a mammal in the rodent order, in the family Castoridae[5]. NatureServe ranks it G5, which means Secure, and lists it as native in 50 US states and territories[2][3].

Conservation status

NatureServe gives the American Beaver a global rank of G5 and a US national rank of N5, and both mean Secure[2][6]. The IUCN Red List category recorded by NatureServe is Least concern[7]. The species is not listed as endangered or threatened under the US Endangered Species Act in USFWS data[1]. NatureServe also estimates the adult population at 10,000 to more than 1,000,000 animals, a wide range[8].

Status Value
Endangered Species Act[1] Not listed
NatureServe global rank[2] G5 (Secure)
NatureServe US rank[6] N5 (Secure)
IUCN Red List (via NatureServe)[7] Least concern
Total population (NatureServe estimate)[8] 10,000 to >1,000,000 individuals

Where American Beaver lives

NatureServe lists the American Beaver as native in 50 US states and territories, including Alaska, Texas, Maine, California and the District of Columbia[3]. NatureServe also gives each state its own conservation rank, shown in the table on this page[9]. These lists show where NatureServe records the species, so they are not a promise that you will see one.

Alaska: native, state rank S5AKMaine: native, state rank S5MEWisconsin: native, state rank S5WIVermont: native, state rank S5VTNew Hampshire: native, state rank S5NHWashington: native, state rank S5WAIdaho: native, state rank S4IDMontana: native, state rank S5MTNorth Dakota: native, state rank S5NDMinnesota: native, state rank SNRMNIllinois: native, state rank S5ILMichigan: native, state rank S5MINew York: native, state rank S5NYMassachusetts: native, state rank S5MAOregon: native, state rank S5ORNevada: native, state rank S4NVWyoming: native, state rank S4WYSouth Dakota: native, state rank S5SDIowa: native, state rank S5IAIndiana: native, state rank S5INOhio: native, state rank SNROHPennsylvania: native, state rank S5PANew Jersey: native, state rank S5NJConnecticut: native, state rank S5CTRhode Island: native, state rank S3RICalifornia: native, state rank SNRCAUtah: native, state rank S4UTColorado: native, state rank S4CONebraska: native, state rank S5NEMissouri: native, state rank S5MOKentucky: native, state rank S5KYWest Virginia: native, state rank S5WVVirginia: native, state rank S5VAMaryland: native, state rank S5MDDelaware: native, state rank S3DEArizona: native, state rank S4AZNew Mexico: native, state rank S3NMKansas: native, state rank S5KSArkansas: native, state rank S5ARTennessee: native, state rank S5TNNorth Carolina: native, state rank S5NCSouth Carolina: native, state rank S5SCDistrict of Columbia: native, state rank S3DCOklahoma: native, state rank SNROKLouisiana: native, state rank S5LAMississippi: native, state rank S5MSAlabama: native, state rank S5ALGeorgia: native, state rank S5GAHawaii: not recordedHITexas: native, state rank S5TXFlorida: native, state rank SNRFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[9].
Show state ranks (50 states)
StateRankMeaning
AlabamaS5Secure
AlaskaS5Secure
ArizonaS4Apparently Secure
ArkansasS5Secure
CaliforniaSNRNot Ranked
ColoradoS4Apparently Secure
ConnecticutS5Secure
DelawareS3Vulnerable
District of ColumbiaS3Vulnerable
FloridaSNRNot Ranked
GeorgiaS5Secure
IdahoS4Apparently Secure
IllinoisS5Secure
IndianaS5Secure
IowaS5Secure
KansasS5Secure
KentuckyS5Secure
LouisianaS5Secure
MaineS5Secure
MarylandS5Secure
MassachusettsS5Secure
MichiganS5Secure
MinnesotaSNRNot Ranked
MississippiS5Secure
MissouriS5Secure
MontanaS5Secure
NebraskaS5Secure
NevadaS4Apparently Secure
New HampshireS5Secure
New JerseyS5Secure
New MexicoS3Vulnerable
New YorkS5Secure
North CarolinaS5Secure
North DakotaS5Secure
OhioSNRNot Ranked
OklahomaSNRNot Ranked
OregonS5Secure
PennsylvaniaS5Secure
Rhode IslandS3Vulnerable
South CarolinaS5Secure
South DakotaS5Secure
TennesseeS5Secure
TexasS5Secure
UtahS4Apparently Secure
VermontS5Secure
VirginiaS5Secure
WashingtonS5Secure
West VirginiaS5Secure
WisconsinS5Secure
WyomingS4Apparently Secure

Habitat

NatureServe records habitat types such as riparian areas, rivers, creeks, pools and shallow or deep water[10]. Beavers live near permanent water of almost any type, from sea level up to more than 3400 m in the mountains[11]. They like slow streams, ponds and small muddy lakes where an outlet can be dammed, and they also use reservoirs and canals when food is there[11]. Fast streams and waters that rise and fall a lot make poor homes[11].

Habitat types recorded by NatureServe[10]

Size, diet and lifespan

The American Beaver is a herbivore, meaning it eats only plants[12][13]. Woody plants such as aspen, willow and cottonwood are favorites, and beavers eat the leaves, bark and twigs[14]. Woody food use is highest in winter and lowest in summer[14]. NatureServe records a typical length of 117 cm (46 in) and a typical adult weight of 27 kg (60 lb)[15][16]. Females reach sexual maturity at about 639 days[17]. Gestation lasts about 128 days[18]. The longest recorded lifespan comes from a beaver in captivity[4].

Trait Value
Typical length[15] 117 cm (46 in)
Typical adult weight[16] 27 kg (60 lb)
Longest recorded lifespan (AnAge)[4] 23.4 years (captivity)
Litter or clutch size[19] 3.5
Gestation or incubation[18] 128 days
Female maturity[17] 639 days (about 1.7 years)
Food habits[12] Herbivore
Active[20] nocturnal, crepuscular
Migration[21] non-migrant

Estimated diet composition (EltonTraits 1.0)[13]

  • 100% other plant material

When to look for it

Beavers are mostly active at dusk, dawn and night, and they are sometimes active by day too[22][23]. They slow down in winter, a state called torpor, but they do not hibernate[22]. NatureServe calls the species a non-migrant, although populations can differ[21]. On GBIF, most US records fall in March, April and May[24]. Those records show when people look and report, not how many animals there are[24].

January: 3,408 recordsJanFebruary: 3,677 recordsFebMarch: 5,340 recordsMarApril: 7,203 recordsAprMay: 5,634 recordsMayJune: 3,824 recordsJunJuly: 3,485 recordsJulAugust: 3,072 recordsAugSeptember: 3,222 recordsSepOctober: 3,088 recordsOctNovember: 2,773 recordsNovDecember: 3,118 recordsDec
US observation records on GBIF by month, all years. The three months with the most records are highlighted. Records show when people look and report, not how many animals there are[24].
Show records by month
MonthRecords
January3,408
February3,677
March5,340
April7,203
May5,634
June3,824
July3,485
August3,072
September3,222
October3,088
November2,773
December3,118

Where to see it

National Park Service species lists record American Beaver as present in 149 park units[25]. Present means the park has a confirmed record, not that sightings are common.

And 125 more park units.

States with the most GBIF observation records: Oregon, Texas, Washington, Massachusetts, California[26]. These counts follow where people look and report, not population size.

Questions people ask

Is the American Beaver endangered?
No. NatureServe ranks it G5, which means Secure, and it is not listed under the US Endangered Species Act in USFWS data[2][1].
Where does the American Beaver live?
NatureServe lists it as native in 50 US states and territories[3]. It lives near permanent water such as rivers, creeks, ponds and reservoirs[10][11].
What does the American Beaver eat?
It is a herbivore. It eats the leaves, bark and twigs of woody plants such as aspen, willow and cottonwood[14][12].
How big is an American Beaver?
NatureServe records a typical length of 117 cm (46 in) and a typical adult weight of 27 kg (60 lb)[15][16].
How long does an American Beaver live?
The longest recorded lifespan comes from a beaver in captivity[4]. That is a record, not a typical lifespan.

Facts and sources

  1. American Beaver is not listed as endangered or threatened under the US Endangered Species Act in USFWS ECOS data (checked 2026-10-30). USFWS ECOS
  2. NatureServe global conservation status rank for American Beaver: G5 (Secure). NatureServe Explorer
  3. NatureServe lists American Beaver as native in 50 US states and territories: Alaska, Alabama, Arkansas, Arizona, California, Colorado, Connecticut, the District of Columbia, Delaware, Florida, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Kentucky,... NatureServe Explorer
  4. Maximum recorded lifespan in AnAge: 23.4 years in captivity. This is a record, not a typical lifespan. AnAge
  5. American Beaver (Castor canadensis) is a mammal in the family Castoridae, order Rodentia. NatureServe Explorer
  6. NatureServe national rank in the United States: N5 (Secure). NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Least concern. NatureServe Explorer
  8. NatureServe estimate of total adult population (global, as a range): 10,000 to >1,000,000 individuals. NatureServe Explorer
  9. NatureServe state ranks for American Beaver (map and table on this page). NatureServe Explorer
  10. Habitat types NatureServe records for American Beaver: Riparian, Big river, Medium river, Creek, Pool, Deep water, Shallow water. NatureServe Explorer
  11. NatureServe notes on habitat for American Beaver. NatureServe Explorer
  12. Adult food habits recorded by NatureServe: Herbivore. NatureServe Explorer
  13. Estimated diet composition in EltonTraits 1.0: 100% other plant material. EltonTraits 1.0
  14. NatureServe notes on food for American Beaver. NatureServe Explorer
  15. Typical length recorded by NatureServe: 117 cm (46 in). NatureServe Explorer
  16. Typical adult weight recorded by NatureServe: 27 kg (60 lb). NatureServe Explorer
  17. Age at female sexual maturity in AnAge: 639 days (about 1.7 years). AnAge
  18. Gestation or incubation period in AnAge: 128 days. AnAge
  19. Typical litter or clutch size in AnAge: 3.5. AnAge
  20. Activity time in EltonTraits 1.0: nocturnal, crepuscular. EltonTraits 1.0
  21. NatureServe migration category for American Beaver: non-migrant (populations can differ). NatureServe Explorer
  22. NatureServe notes on phenology for American Beaver. NatureServe Explorer
  23. Adult activity patterns recorded by NatureServe: Nocturnal, Crepuscular. NatureServe Explorer
  24. GBIF observation records of American Beaver in the US by month (chart on this page). GBIF
  25. NPSpecies park lists recording American Beaver as present (list on this page). NPS NPSpecies
  26. US states with the most GBIF observation records of American Beaver: Oregon, Texas, Washington, Massachusetts, California. Record counts follow observer effort, not population size. GBIF

Status, range and habitat come from NatureServe Explorer (CC BY 4.0) and USFWS ECOS at the snapshot date. Listings change by federal rule. State lists are where NatureServe records the species, not a promise that you will see it there. Never name a place smaller than a state. GBIF and park records count observations and checklists. They show where and when people report the species, not how many animals live there.

NatureServe. 2026. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org. (Accessed: October 30, 2026). Licensed under CC BY 4.0; SpeciesFacts selected and summarized it.

Photo: Vlad Podvorny, CC BY 2.0, via Wikimedia Commons.