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North American River Otter

Lontra canadensis

Mammal · family Mustelidae · order Carnivora

  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.

North American River Otter
Photo: Jeremy T. Hetzel from Boston, USA, CC BY 2.0, via Wikimedia Commons.
Endangered Species Act
Not listed[1]
NatureServe global rank
G5 Secure[2]
Native in
48 states[3]
Longest recorded life
27 years[4]

The North American river otter is a water-loving mammal in the weasel family, Mustelidae[5]. NatureServe ranks it Secure worldwide[2]. It is native to 48 US states and territories[3].

Conservation status

NatureServe gives the river otter a global rank of G5 and a US rank of N5, and both mean Secure[2][6]. The IUCN Red List category recorded by NatureServe is Least concern[7]. It is not listed as Endangered or Threatened under the US Endangered Species Act[1]. International trade in it is controlled under CITES Appendix II[8]. NatureServe notes that the population trend is probably fairly stable overall[9].

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
CITES (international trade)[8] Appendix II
Total population (NatureServe estimate)[10] 10,000 to >1,000,000 individuals

Where North American River Otter lives

NatureServe lists the river otter as native in 48 US states and territories, including Alaska, California, Florida, Maine and Texas[3]. It is ranked as extirpated or possibly extirpated, which means gone or maybe gone, in Arizona and New Mexico[11]. State ranks vary, so it is more secure in some states than in others[12]. Reports on GBIF come most often from California, Florida, Washington, Oregon and Texas, but that mostly reflects where people look and report[13].

Alaska: native, state rank S5AKMaine: native, state rank S5MEWisconsin: native, state rank S4WIVermont: native, state rank S5VTNew Hampshire: native, state rank S5NHWashington: native, state rank S4WAIdaho: native, state rank S4IDMontana: native, state rank S5MTNorth Dakota: native, state rank S3NDMinnesota: native, state rank SNRMNIllinois: native, state rank S2ILMichigan: native, state rank S4MINew York: native, state rank S5NYMassachusetts: native, state rank S4MAOregon: native, state rank S4ORNevada: native, state rank S2NVWyoming: native, state rank S3WYSouth Dakota: native, state rank S3SDIowa: native, state rank S3IAIndiana: native, state rank S5INOhio: native, state rank S3OHPennsylvania: native, state rank S4PANew Jersey: native, state rank S4NJConnecticut: native, state rank S5CTRhode Island: native, state rank S4RICalifornia: native, state rank SNRCAUtah: native, state rank S3UTColorado: native, state rank S3CONebraska: native, state rank S4NEMissouri: native, state rank S5MOKentucky: native, state rank S3KYWest Virginia: native, state rank S4WVVirginia: native, state rank S4VAMaryland: native, state rank S5MDDelaware: native, state rank S4DEArizona: extirpated or possibly extirpated, state rank SH,SNAAZNew Mexico: extirpated or possibly extirpated, state rank SHNMKansas: native, state rank S3KSArkansas: native, state rank S5ARTennessee: native, state rank S3TNNorth Carolina: native, state rank S4NCSouth Carolina: native, state rank S4SCDistrict of Columbia: native, state rank S1DCOklahoma: native, state rank S3OKLouisiana: native, state rank S4LAMississippi: native, state rank S4MSAlabama: native, state rank S4ALGeorgia: native, state rank S5GAHawaii: not recordedHITexas: native, state rank S3TXFlorida: native, state rank SNRFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[12].
Show state ranks (50 states)
StateRankMeaning
AlabamaS4Apparently Secure
AlaskaS5Secure
ArizonaSH,SNAPossibly Extirpated, Not Applicable
ArkansasS5Secure
CaliforniaSNRNot Ranked
ColoradoS3Vulnerable
ConnecticutS5Secure
DelawareS4Apparently Secure
District of ColumbiaS1Critically Imperiled
FloridaSNRNot Ranked
GeorgiaS5Secure
IdahoS4Apparently Secure
IllinoisS2Imperiled
IndianaS5Secure
IowaS3Vulnerable
KansasS3Vulnerable
KentuckyS3Vulnerable
LouisianaS4Apparently Secure
MaineS5Secure
MarylandS5Secure
MassachusettsS4Apparently Secure
MichiganS4Apparently Secure
MinnesotaSNRNot Ranked
MississippiS4Apparently Secure
MissouriS5Secure
MontanaS5Secure
NebraskaS4Apparently Secure
NevadaS2Imperiled
New HampshireS5Secure
New JerseyS4Apparently Secure
New MexicoSHPossibly Extirpated
New YorkS5Secure
North CarolinaS4Apparently Secure
North DakotaS3Vulnerable
OhioS3Vulnerable
OklahomaS3Vulnerable
OregonS4Apparently Secure
PennsylvaniaS4Apparently Secure
Rhode IslandS4Apparently Secure
South CarolinaS4Apparently Secure
South DakotaS3Vulnerable
TennesseeS3Vulnerable
TexasS3Vulnerable
UtahS3Vulnerable
VermontS5Secure
VirginiaS4Apparently Secure
WashingtonS4Apparently Secure
West VirginiaS4Apparently Secure
WisconsinS4Apparently Secure
WyomingS3Vulnerable

Habitat

NatureServe records many wet habitats for the river otter, such as creeks, rivers, wetlands, lagoons, tidal flats and near-shore waters[14]. In some places it also lives along the outer coast in Alaska and the Pacific Northwest[15]. When resting, it uses spots like hollow logs, root hollows, old beaver lodges, thickets near water or burrows made by other animals[15]. It returns to the same haul-out sites on the banks, and it can travel a long way over land, especially in snow[15].

Habitat types recorded by NatureServe[14]

Size, diet and lifespan

Adults are about 131 cm (52 in) long[16]. Their typical weight is 30 lb[17]. NatureServe records the river otter as a carnivore that eats fish and invertebrates[18]. One estimate puts its diet at 90% fish and 10% reptiles and amphibians[19]. It also eats frogs, crayfish, turtles and insects, and sometimes birds and small mammals[20]. Litters hold 1 to 6 young, averaging 2 to 3, and there is 1 litter per year[21]. Young are weaned at about 3 months and stay with their mother for about a year[21]. The longest recorded lifespan is 27 years, in captivity[4].

Trait Value
Typical length[16] 131 cm (52 in)
Typical adult weight[17] 13.6 kg (30 lb)
Longest recorded lifespan (AnAge)[4] 27 years (captivity)
Litter or clutch size[22] 2.5
Gestation or incubation[23] 62 days
Female maturity[24] 730 days (about 2.0 years)
Food habits[18] Carnivore, Piscivore, Invertivore
Active[25] nocturnal, crepuscular
Migration[26] non-migrant

Estimated diet composition (EltonTraits 1.0)[19]

  • 90% fish
  • 10% reptiles and amphibians

When to look for it

The river otter does not migrate, though populations can differ[26]. It stays active in winter, even in deep fresh snow[27]. Activity can fall at any hour[27]. One source calls it nocturnal and crepuscular, which means active at night and around dawn and dusk[25]. GBIF records are highest in January, February and December, but that shows when people report otters, not how many there are[28].

January: 2,673 recordsJanFebruary: 2,174 recordsFebMarch: 2,002 recordsMarApril: 2,099 recordsAprMay: 1,384 recordsMayJune: 1,268 recordsJunJuly: 1,398 recordsJulAugust: 1,473 recordsAugSeptember: 1,506 recordsSepOctober: 1,475 recordsOctNovember: 1,795 recordsNovDecember: 2,496 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[28].
Show records by month
MonthRecords
January2,673
February2,174
March2,002
April2,099
May1,384
June1,268
July1,398
August1,473
September1,506
October1,475
November1,795
December2,496

Where to see it

National Park Service species lists record North American River Otter as present in 81 park units[29]. Present means the park has a confirmed record, not that sightings are common.

And 57 more park units.

States with the most GBIF observation records: California, Florida, Washington, Oregon, Texas[13]. These counts follow where people look and report, not population size.

Questions people ask

Is the North American river otter endangered?
No. NatureServe ranks it Secure worldwide and in the US, and it is not listed as Endangered or Threatened under the Endangered Species Act[2][6][1].
Where do river otters live in the US?
NatureServe lists them as native in 48 US states and territories[3]. They are ranked as extirpated or possibly extirpated in Arizona and New Mexico[11].
What do river otters eat?
One estimate says 90% fish and 10% reptiles and amphibians[19]. NatureServe also lists frogs, crayfish, turtles and insects[20].
How big is a river otter?
NatureServe records a typical length of 131 cm (52 in)[16]. Typical adult weight is 30 lb[17].
How long do river otters live?
The longest recorded lifespan is 27 years, in captivity[4]. This is a record, not a typical lifespan[4].

Facts and sources

  1. North American River Otter 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 North American River Otter: G5 (Secure). NatureServe Explorer
  3. NatureServe lists North American River Otter as native in 48 US states and territories: Alaska, Alabama, Arkansas, California, Colorado, Connecticut, the District of Columbia, Delaware, Florida, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Kentucky,... NatureServe Explorer
  4. Maximum recorded lifespan in AnAge: 27 years in captivity. This is a record, not a typical lifespan. AnAge
  5. North American River Otter (Lontra canadensis) is a mammal in the family Mustelidae, order Carnivora. 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. CITES listing recorded by NatureServe: Appendix II (controls on international trade). NatureServe Explorer
  9. NatureServe notes on trend for North American River Otter. NatureServe Explorer
  10. NatureServe estimate of total adult population (global, as a range): 10,000 to >1,000,000 individuals. NatureServe Explorer
  11. NatureServe ranks North American River Otter as extirpated or possibly extirpated (SX or SH) in: Arizona, New Mexico. NatureServe Explorer
  12. NatureServe state ranks for North American River Otter (map and table on this page). NatureServe Explorer
  13. US states with the most GBIF observation records of North American River Otter: California, Florida, Washington, Oregon, Texas. Record counts follow observer effort, not population size. GBIF
  14. Habitat types NatureServe records for North American River Otter: Herbaceous wetland, Scrub-shrub wetland, Forested wetland, Riparian, Big river, Medium river, Creek, Moderate gradient, Low gradient, Pool, Deep water, Shallow water, River mouth/tidal... NatureServe Explorer
  15. NatureServe notes on habitat for North American River Otter. NatureServe Explorer
  16. Typical length recorded by NatureServe: 131 cm (52 in). NatureServe Explorer
  17. Typical adult weight recorded by NatureServe: 13.6 kg (30 lb). NatureServe Explorer
  18. Adult food habits recorded by NatureServe: Carnivore, Piscivore, Invertivore. NatureServe Explorer
  19. Estimated diet composition in EltonTraits 1.0: 90% fish, 10% reptiles and amphibians. EltonTraits 1.0
  20. NatureServe notes on food for North American River Otter. NatureServe Explorer
  21. NatureServe notes on reproduction for North American River Otter. NatureServe Explorer
  22. Typical litter or clutch size in AnAge: 2.5. AnAge
  23. Gestation or incubation period in AnAge: 62 days. AnAge
  24. Age at female sexual maturity in AnAge: 730 days (about 2.0 years). AnAge
  25. Activity time in EltonTraits 1.0: nocturnal, crepuscular. EltonTraits 1.0
  26. NatureServe migration category for North American River Otter: non-migrant (populations can differ). NatureServe Explorer
  27. NatureServe notes on phenology for North American River Otter. NatureServe Explorer
  28. GBIF observation records of North American River Otter in the US by month (chart on this page). GBIF
  29. NPSpecies park lists recording North American River Otter as present (list on this page). NPS NPSpecies

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: Jeremy T. Hetzel from Boston, USA, CC BY 2.0, via Wikimedia Commons.