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Great Gray Owl

Strix nebulosa

Bird · family Strigidae · order Strigiformes

  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.

Endangered Species Act
Not listed[1]
NatureServe global rank
G5 Secure[2]
Native in
12 states[3]
Oldest known wild bird
18 years[4]

The Great Gray Owl (Strix nebulosa) is a bird in the owl family Strigidae[5]. It is not listed under the US Endangered Species Act, and NatureServe lists it as native in 12 US states and territories[1][3].

Conservation status

NatureServe gives the Great Gray Owl a global rank of G5 (Secure) and a United States rank of N4 (Apparently Secure)[2][6]. The IUCN Red List category recorded by NatureServe is Least concern[7]. The bird is not listed as endangered or threatened under the US Endangered Species Act[1]. It is on the federal list of birds protected under the Migratory Bird Treaty Act, and CITES records it in Appendix II, which sets controls on international trade[8][9].

Status Value
Endangered Species Act[1] Not listed
NatureServe global rank[2] G5 (Secure)
NatureServe US rank[6] N4 (Apparently Secure)
IUCN Red List (via NatureServe)[7] Least concern
Migratory Bird Treaty Act[8] Protected
CITES (international trade)[9] Appendix II
Total population (NatureServe estimate)[10] 10,000 to >1,000,000 individuals

Where Great Gray Owl lives

NatureServe lists the Great Gray Owl as native in Alaska, California, Idaho, Maine, Michigan, Minnesota, Montana, New York, Oregon, Utah, Washington and Wyoming[3]. NatureServe gives it a separate conservation rank in each of those states[11]. Observation records on GBIF are most numerous for Minnesota, Montana, Oregon, California and Alaska, but that follows where people look and report, not how many owls live there[12].

Alaska: native, state rank S4AKMaine: native, state rank S1NMEWisconsin: not recordedWIVermont: not recordedVTNew Hampshire: not recordedNHWashington: native, state rank S2BWAIdaho: native, state rank S3IDMontana: native, state rank S3MTNorth Dakota: not recordedNDMinnesota: native, state rank SNRMNIllinois: not recordedILMichigan: native, state rank SNRNMINew York: native, state rank SNRNNYMassachusetts: not recordedMAOregon: native, state rank S3ORNevada: not recordedNVWyoming: native, state rank S2WYSouth Dakota: not recordedSDIowa: not recordedIAIndiana: not recordedINOhio: not recordedOHPennsylvania: not recordedPANew Jersey: not recordedNJConnecticut: not recordedCTRhode Island: not recordedRICalifornia: native, state rank S1CAUtah: native, state rank S1NUTColorado: not recordedCONebraska: not recordedNEMissouri: not recordedMOKentucky: not recordedKYWest Virginia: not recordedWVVirginia: not recordedVAMaryland: not recordedMDDelaware: not recordedDEArizona: not recordedAZNew Mexico: not recordedNMKansas: not recordedKSArkansas: not recordedARTennessee: not recordedTNNorth Carolina: not recordedNCSouth Carolina: not recordedSCDistrict of Columbia: not recordedDCOklahoma: not recordedOKLouisiana: not recordedLAMississippi: not recordedMSAlabama: not recordedALGeorgia: not recordedGAHawaii: not recordedHITexas: not recordedTXFlorida: not recordedFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[11].
Show state ranks (12 states)
StateRankMeaning
AlaskaS4Apparently Secure
CaliforniaS1Critically Imperiled
IdahoS3Vulnerable
MaineS1NCritically Imperiled (nonbreeding)
MichiganSNRNNot Ranked (nonbreeding)
MinnesotaSNRNot Ranked
MontanaS3Vulnerable
New YorkSNRNNot Ranked (nonbreeding)
OregonS3Vulnerable
UtahS1NCritically Imperiled (nonbreeding)
WashingtonS2BImperiled (breeding)
WyomingS2Imperiled

Habitat

NatureServe records forests of hardwood, conifer and mixed trees, plus woodlands, grassland, bogs and fens, and streamside areas[13]. The owl is described in dense conifer and hardwood forest, often near water, where it hunts in wet meadows[14]. In the far north it uses boreal forest and bogs, and in mountains it uses conifer forest and meadows[14]. It nests on broken tree trunks, in old nests of other large birds, or on debris platforms, often near bogs or clearings[14].

Habitat types recorded by NatureServe[13]

Size, diet and lifespan

NatureServe lists the Great Gray Owl as a carnivore, and its diet in North America is mostly pocket gophers and voles[15][16]. One diet estimate is 70% warm-blooded vertebrates, 20% reptiles and amphibians, and 10% invertebrates[17]. It usually hunts in open areas with scattered trees or forest edges, and it can use sound to find prey under snow[16]. A typical adult is 69 cm (27 in) long[18]. It weighs about 3 lb[19]. A clutch is 2 to 5 eggs, and the female incubates them for 28 to 29 days while the male brings food[20]. The oldest known banded wild owl was at least 18 years 9 months old[4].

Trait Value
Typical length[18] 69 cm (27 in)
Typical adult weight[19] 1.3 kg (3 lb)
Longest recorded lifespan (AnAge)[21] 16.1 years (wild)
Oldest known wild bird (banding)[4] 18 years 9 months
Litter or clutch size[22] 2
Gestation or incubation[23] 30 days
Female maturity[24] 365 days (about 1.0 years)
Food habits[15] Carnivore
Migration[25] non-migrant

Estimated diet composition (EltonTraits 1.0)[17]

  • 70% warm-blooded vertebrates
  • 20% reptiles and amphibians
  • 10% invertebrates

When to look for it

NatureServe records the Great Gray Owl as non-migrant, though populations can differ[25]. In winter it hunts mostly around dawn and in the hours before dusk, and when nesting it may hunt by day or night[26]. Some owls may move several hundred km south for winter, and they move more in years when food is scarce[27]. GBIF records are highest in January, February and March, which reflects when people look and report[28].

January: 545 recordsJanFebruary: 634 recordsFebMarch: 381 recordsMarApril: 177 recordsAprMay: 154 recordsMayJune: 181 recordsJunJuly: 56 recordsJulAugust: 86 recordsAugSeptember: 88 recordsSepOctober: 93 recordsOctNovember: 96 recordsNovDecember: 254 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
January545
February634
March381
April177
May154
June181
July56
August86
September88
October93
November96
December254

Where to see it

National Park Service species lists record Great Gray Owl as present in 20 park units[29]. Present means the park has a confirmed record, not that sightings are common.

States with the most GBIF observation records: Minnesota, Montana, Oregon, California, Alaska[12]. These counts follow where people look and report, not population size.

Questions people ask

Is the Great Gray Owl endangered?
It is not listed as endangered or threatened under the US Endangered Species Act[1]. NatureServe ranks it G5 (Secure) globally and N4 (Apparently Secure) in the United States[2][6].
Where does the Great Gray Owl live?
NatureServe lists it as native in 12 US states and territories, including Alaska, Minnesota, Montana, Oregon and Wyoming[3]. It lives in forests, woodlands, grassland and bogs[13].
What does the Great Gray Owl eat?
Its diet in North America is mostly pocket gophers and voles[16]. It can use sound to find prey under snow[16].
How big is a Great Gray Owl?
A typical adult is 69 cm (27 in) long[18]. It weighs about 3 lb[19].
How long does a Great Gray Owl live?
The oldest known banded wild owl was at least 18 years 9 months old[4]. That is a record, not a typical lifespan.

Facts and sources

  1. Great Gray Owl 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 Great Gray Owl: G5 (Secure). NatureServe Explorer
  3. NatureServe lists Great Gray Owl as native in 12 US states and territories: Alaska, California, Idaho, Maine, Michigan, Minnesota, Montana, New York, Oregon, Utah, Washington, Wyoming. NatureServe Explorer
  4. Oldest known wild Great Gray Owl from US and Canadian bird banding records: at least 18 years 9 months old (USGS Bird Banding Laboratory). USGS Bird Banding Lab
  5. Great Gray Owl (Strix nebulosa) is a bird in the family Strigidae, order Strigiformes. NatureServe Explorer
  6. NatureServe national rank in the United States: N4 (Apparently Secure). NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Least concern. NatureServe Explorer
  8. Great Gray Owl is on the federal list of migratory birds protected under the Migratory Bird Treaty Act (50 CFR 10.13). eCFR, 50 CFR 10.13
  9. CITES listing recorded by NatureServe: Appendix II (controls on international trade). NatureServe Explorer
  10. NatureServe estimate of total adult population (global, as a range): 10,000 to >1,000,000 individuals. NatureServe Explorer
  11. NatureServe state ranks for Great Gray Owl (map and table on this page). NatureServe Explorer
  12. US states with the most GBIF observation records of Great Gray Owl: Minnesota, Montana, Oregon, California, Alaska. Record counts follow observer effort, not population size. GBIF
  13. Habitat types NatureServe records for Great Gray Owl: Forest - hardwood, Forest - conifer, Forest - mixed, Woodland - hardwood, Woodland - conifer, Woodland - mixed, Grassland/herbaceous, Bog/fen, Riparian. NatureServe Explorer
  14. NatureServe notes on habitat for Great Gray Owl. NatureServe Explorer
  15. Adult food habits recorded by NatureServe: Carnivore. NatureServe Explorer
  16. NatureServe notes on food for Great Gray Owl. NatureServe Explorer
  17. Estimated diet composition in EltonTraits 1.0: 70% warm-blooded vertebrates, 20% reptiles and amphibians, 10% invertebrates. EltonTraits 1.0
  18. Typical length recorded by NatureServe: 69 cm (27 in). NatureServe Explorer
  19. Typical adult weight recorded by NatureServe: 1.3 kg (3 lb). NatureServe Explorer
  20. NatureServe notes on reproduction for Great Gray Owl. NatureServe Explorer
  21. Maximum recorded lifespan in AnAge: 16.1 years in the wild. This is a record, not a typical lifespan. AnAge
  22. Typical litter or clutch size in AnAge: 2. AnAge
  23. Gestation or incubation period in AnAge: 30 days. AnAge
  24. Age at female sexual maturity in AnAge: 365 days (about 1.0 years). AnAge
  25. NatureServe migration category for Great Gray Owl: non-migrant (populations can differ). NatureServe Explorer
  26. NatureServe notes on phenology for Great Gray Owl. NatureServe Explorer
  27. NatureServe notes on migration for Great Gray Owl. NatureServe Explorer
  28. GBIF observation records of Great Gray Owl in the US by month (chart on this page). GBIF
  29. NPSpecies park lists recording Great Gray Owl 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.