Aegolius funereus - (Linnaeus, 1758)
Boreal Owl
Taxonomic Status: Accepted
Related ITIS Name(s): Aegolius funereus (Linnaeus, 1758) (TSN 177938)
French Common Names: nyctale de Tengmalm
Unique Identifier: ELEMENT_GLOBAL.2.105053
Element Code: ABNSB15010
Informal Taxonomy: Animals, Vertebrates - Birds - Other Birds
 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Strigiformes Strigidae Aegolius
Genus Size: B - Very small genus (2-5 species)
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Concept Reference Code: B98AOU01NAUS
Name Used in Concept Reference: Aegolius funereus
Taxonomic Comments: Known as Tengmalm's Owl in European literature (AOU 1998).
Conservation Status
Help

NatureServe Status

Global Status: G5
Global Status Last Reviewed: 06Apr2016
Global Status Last Changed: 27Nov1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Reasons: Wide range, apparently large numbers and occurrences seem to make this species secure.
Nation: United States
National Status: N4 (05Jan1997)
Nation: Canada
National Status: N5 (17Aug2015)

U.S. & Canada State/Province Status
United States Alaska (S4), Colorado (S2), Idaho (S2), Maine (SNA), Michigan (SNRN), Minnesota (SNRB,SNRN), Montana (S4), New Mexico (S2B,S2N), New York (SNRN), Oregon (S3?), Washington (S3), Wisconsin (SNA), Wyoming (S2)
Canada Alberta (S4), British Columbia (S4), Labrador (S3S4), Manitoba (S3S4B), New Brunswick (S1S2B), Newfoundland Island (S4), Northwest Territories (S4S5), Nova Scotia (S1B), Nunavut (SNR), Ontario (S4), Prince Edward Island (SU), Quebec (S4), Saskatchewan (S3B,S3N), Yukon Territory (S4)

Other Statuses

Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Not at Risk (01Apr1995)
IUCN Red List Category: LC - Least concern
Convention on International Trade in Endangered Species Protection Status (CITES): Appendix II

NatureServe Global Conservation Status Factors

Range Extent: 20,000 to >2,500,000 square km (about 8000 to >1,000,000 square miles)
Range Extent Comments: Breeds in North America from treeline in central Alaska east to Newfoundland; south central Oregon in the Cascade and Blue Mountains, and in the Rocky Mountains south through Washington, Idaho, Montana, Wyoming, and Colorado to northern New Mexico; then east through central Saskatchewan, southern Manitoba, northern Minnesota, southern Quebec and Ontario. Breeds in Eurasia from treeline in northern Scandanavia, Russia, and Siberia, south in the mountians to southern Europe, the western Himalayas, and western China (AOU 1983, Hayward and Hayward 1993). Winters mainly in hte breeding range, however it may move south in the eastern U.S. and Europe during eruption years (A.O.U. 1983, Hayward and Hayward 1993).

Number of Occurrences: 81 to >300

Population Size: 10,000 to >1,000,000 individuals
Population Size Comments: Population "large" in Canada (1995 COEWIC unpubl. report).

Overall Threat Impact Comments: Major threat may be indirect effects of forest harvesting practices. These may reduce primary prey populaitons, remove forest structure used for foraging, and eliminates nesting cavities (Hayward and Hayward 1993).

Short-term Trend: Unknown
Short-term Trend Comments: Unknown. Reliable populations number unavailable and nomadism caused by fluctuating prey density complicates this further (Hayward and Hayward 1993). Population "stable" in Canada (COSEWIC 1995 unpubl. report). Although recently discovered breeding far to the south of previously known locations, this is probably due the season and location of breeding (high elevation in February-April) rather than range expansion (Stahlecker and Duncan 1996).

Other NatureServe Conservation Status Information

Inventory Needs: May be breeding in northern Wisconsin, Michigan, and Maine, and the mountians of Utah, California, and New England (Hayward and Hayward 1993).

Distribution
Help
Global Range: (20,000 to >2,500,000 square km (about 8000 to >1,000,000 square miles)) Breeds in North America from treeline in central Alaska east to Newfoundland; south central Oregon in the Cascade and Blue Mountains, and in the Rocky Mountains south through Washington, Idaho, Montana, Wyoming, and Colorado to northern New Mexico; then east through central Saskatchewan, southern Manitoba, northern Minnesota, southern Quebec and Ontario. Breeds in Eurasia from treeline in northern Scandanavia, Russia, and Siberia, south in the mountians to southern Europe, the western Himalayas, and western China (AOU 1983, Hayward and Hayward 1993). Winters mainly in hte breeding range, however it may move south in the eastern U.S. and Europe during eruption years (A.O.U. 1983, Hayward and Hayward 1993).

U.S. States and Canadian Provinces
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, CO, ID, ME, MI, MN, MT, NM, NY, OR, WA, WI, WY
Canada AB, BC, LB, MB, NB, NF, NS, NT, NU, ON, PE, QC, SK, YT

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: WILDSPACETM 2002


U.S. Distribution by County Help
State County Name (FIPS Code)
CO Chaffee (08015), Clear Creek (08019), Conejos (08021)*, Delta (08029), Dolores (08033), Eagle (08037), Garfield (08045), Grand (08049), Gunnison (08051), Hinsdale (08053), Jackson (08057), Larimer (08069), Mesa (08077), Mineral (08079), Moffat (08081), Montezuma (08083), Ouray (08091)*, Park (08093), Pitkin (08097), Rio Blanco (08103), Rio Grande (08105), Routt (08107), San Juan (08111), San Miguel (08113), Summit (08117)
ID Adams (16003), Bear Lake (16007), Blaine (16013), Bonner (16017), Boundary (16021), Caribou (16029), Clark (16033), Clearwater (16035), Fremont (16043), Idaho (16049), Lemhi (16059), Shoshone (16079), Teton (16081), Valley (16085)
MN Cook (27031), Lake (27075), St. Louis (27137)
NM Mora (35033)*, Rio Arriba (35039), Santa Fe (35049), Taos (35055)*
OR Baker (41001)*, Deschutes (41017), Grant (41023)*, Jefferson (41031), Umatilla (41059)*, Union (41061)*, Wallowa (41063)*
WA Pend Oreille (53051)+
WY Albany (56001), Fremont (56013), Lincoln (56023), Sublette (56035), Uinta (56041)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
04 Baptism-Brule (04010101)+, St. Louis (04010201)+
09 Rainy Headwaters (09030001)+
10 Upper Wind (10080001)+, North Platte Headwaters (10180001)+, Upper Laramie (10180010)+, Upper South Platte (10190002)+, Clear (10190004)+, Big Thompson (10190006)+*, Cache La Poudre (10190007)+
11 Arkansas Headwaters (11020001)+
13 Rio Grande headwaters (13010001)+, Conejos (13010005)+, Upper Rio Grande (13020101)+, Rio Chama (13020102)+, Rio Grande-Santa Fe (13020201)+, Pecos headwaters (13060001)+
14 Colorado headwaters (14010001)+, Blue (14010002)+, Eagle (14010003)+, Roaring Fork (14010004)+, Colorado headwaters-Plateau (14010005)+, East-Taylor (14020001)+, Upper Gunnison (14020002)+, Tomichi (14020003)+*, Lower Gunnison (14020005)+, Uncompahange (14020006)+*, Upper Dolores (14030002)+, San Miguel (14030003)+, Upper Green (14040101)+, Upper Yampa (14050001)+, Little Snake (14050003)+, Upper White (14050005)+, Piedra (14080102)+, Animas (14080104)+, Mancos (14080107)+
16 Upper Bear (16010101)+, Bear Lake (16010201)+, Middle Bear (16010202)+
17 Lower Kootenai (17010104)+, Moyie (17010105)+, Pend Oreille Lake (17010214)+, Priest (17010215)+, Pend Oreille (17010216)+, St. Joe (17010304)+, Greys-Hobock (17040103)+, Upper Henrys (17040202)+, Teton (17040204)+, Blackfoot (17040207)+, Portneuf (17040208)+, Beaver-Camas (17040214)+, North Fork Payette (17050123)+, Powder (17050203)+*, Upper Grande Ronde (17060104)+*, Wallowa (17060105)+*, Lower Grande Ronde (17060106)+*, Upper Salmon (17060201)+, Middle Salmon-Panther (17060203)+, Upper Middle Fork Salmon (17060205)+, Middle Salmon-Chamberlain (17060207)+, South Fork Salmon (17060208)+, Little Salmon (17060210)+, Lower Selway (17060302)+, Lochsa (17060303)+, South Fork Clearwater (17060305)+, Upper North Fork Clearwater (17060307)+, Lower North Fork Clearwater (17060308)+, Walla Walla (17070102)+*, North Fork John Day (17070202)+*, Upper Deschutes (17070301)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Help
Basic Description: A small owl
Reproduction Comments: Female may occupy the nest cavity 1-3 weeks prior to egg laying (Hayward 1989). In Colorado, nests were initiated from mid-April to early June; mid-April to late May in Idaho (Hayward 1989). Clutch size usually is 4-6. Incubation reported as 25-36 days, by female. Young fledge at about 4-5 weeks, independent at 5-6 weeks, sexually mature by 1 year. Mating system variable. See Johnsgard (1988).
Ecology Comments: In Idaho, annual home range averaged 1528 ha (522-4119 ha); home ranges overlapped extensively; range was larger in winter than in summer; center of winter and summer ranges were separated by average of 2333 m (Hayward et al. 1987). Defends nest site only.
Non-Migrant: Y
Locally Migrant: Y
Long Distance Migrant: N
Mobility and Migration Comments: Periodic large-scale southward irruptions in North America, frequently in synchrony with similar movements of great gray and hawk-owl. Tends to occur at higher elevations in summer; may move to lower elevation for winter. In Colorado, some males remain at high elevations all year; others wander extensively (Johnsgard 1988).
Terrestrial Habitat(s): Forest - Conifer, Forest - Hardwood, Forest - Mixed
Special Habitat Factors: Standing snag/hollow tree
Habitat Comments: Dense coniferous forest, mixed forest, thickets of alder, aspen, or stunted spruce, most commonly in proximity to open grassy situations (AOU 1983); muskeg bogs. In the Rockies, occurs generally in mature, multilayered spruce-fir forest. Roosts in dense cover by day, in cool microsites in summer; frequently changes roosting site.

Nests in tree hole, natural cavity or old woodpecker hole; sometimes in artificial nest boxes (Harrison 1978). Nest site may be used in consecutive years. Three nest holes in Colorado were 78-100 mm in diameter (see Johnsgard 1988). A nest in Montana was in a dead broken-topped subalpine fir; the cavity opening measured 73 mm X 64 mm (Holt and Ermatinger 1989).

Adult Food Habits: Carnivore
Immature Food Habits: Carnivore
Food Comments: Eats mainly small mammals (often MICROTUS and CLETHRIONOMYS, also SOREX and PEROMYSCUS); also sometimes birds and insects (Bent 1938, Ryder et al. 1987, Hayward 1989).
Adult Phenology: Circadian
Immature Phenology: Circadian
Phenology Comments: May forage day or night; most hunting occurs at night (Hayward 1989).
Length: 25 centimeters
Weight: 167 grams
Economic Attributes Not yet assessed
Help
Management Summary
Help
Preserve Selection & Design Considerations: Because of large home ranges and low population densities, planning (management) areas should exceed 1000 sq km of suitable habitat (Hayward 1989).
Management Requirements: Snag management guidelines for pileated woodpeckers should be followed (Rodrick and Milner 1991). Aspen groves with large diameter trees should be maintained. Uneven-age timber management may be compatible, but clearcuts are not considered suitable habitat for foraging (Hayward 1989).
Monitoring Requirements: To detect owls in Rocky Mountains: biweekly surveys in March-April; minimum of 3 years of censusing may be needed because of low vocal activity in some years; census on clear calm nights (Palmer 1987). Singing males generally are within 200 m of the nest cavity during the courtship period (Hayward 1989). Also, nest boxes may be used to monitor populations (Hayward et al. 1992). See Bull (1987) for capture techniques.

Duncan and Duncan (1995) described a standardized method used for general owl surveys in Manitoba. Surveys are conducted during the first two weeks of April. They must begin at least 30 minutes after sunset, must end at least 30 minutes before sunrise. Routes average 25 km in length and are travelled by car with stops every 0.8 km. At each stop, volunteers listen for an initial 1-minute period and note all owls heard or seen, including direction from the stop and loudness (to prevent double-counting). Other vertebrates seen also are counted. After the initial 1-minute listening period, the tape-recorded call of a male boreal owl is played for 20 seconds, followed by another minute of listening. Next the tape-recorded call of a male great gray owl is played for 20 seconds, and again all owls seen or heard during the next 1-minute period are noted.

Population/Occurrence Delineation
Help
Group Name: Small and Medium Owls

Use Class: Breeding
Subtype(s): Nest site
Minimum Criteria for an Occurrence: Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance is not intended to delineate demographically independent populations or metapopulations (such units would be quite large) but rather serves to circumscribe breeding occurrences that are of practical size for conservation/management use.

Separation distance is larger than three times the diameter of an average home range for these volant species; based the diameter of larger home ranges of males, e.g. those of Northern Pygmy-Owls given below.

Ferruginous Pygmy-Owl: post-fledging families used 9.3 to about 60 hectares until the young dispersed (Proudfoot and Johnson 2000).

Northern Pygmy-Owl: territory in Colorado estimated to be about 75 hectares (Rashid 1999, cited in Holt and Petersen 2000); home ranges of breeding males in Washington 170-230 hectares (A. Giese, pers. comm., cited in Holt and Petersen 2000); home ranges of males in Sweden averaged 231 hectares (Kullberg 1995).

Northern Saw-whet Owl: Two breeding males had home ranges of 142 and 159 hectares (Cannings 1987). Most breeding habitat probably supports a maximum of about 1 pair/square kilometer, often much less (Cannings 1993); singing males can be as close as about 250 meters apart (Swengel 1990).

Elf Owl: home ranges smaller, range 0.2-2.6, mean 1.0 hectares (Gamel 1997).

Flammulated Owl males had mean home ranges of about 14 hectares in Colorado (Linkhart 1984) and about 16 hectares in Oregon (during the incubation period; Goggans 1986). DNA data indicate very low differentiation among populations in different mountain ranges in New Mexico and Utah; evidently the species exhibits long-distance natal dispersal and frequent intermountain dispersal (Arsenault et al. 2005).

Whiskered Screech-Owls had home ranges about 1550 meters long, along permanent creek (Gehlbach and Gehlbach 2000).

Burrowing Owl: In Saskatchewan, the average home range was about 1.2 kilometers in diameter (Haug and Oliphant 1990).

Long-eared Owl: In Wyoming, breeding home range in riparian habitat varied from 34-106 hectares and averaged 51 hectares (Craighead and Craighead 1956).

Short-eared Owl: Breeding territories average 64 -74 hectares (Holt 1992, Clark 1975).

Inferred Minimum Extent of Habitat Use (when actual extent is unknown): .6 km
Inferred Minimum Extent Justification: Conservatively based on an average home range of 27 hectares for a Ferruginous Pygmy-Owl family (Proudfoot and Johnson 2000). A breeding male Northern Saw-whet Owl spent most of its active time in a core area of only 27 hectares (Cannings 1987).

Long-eared Owl: May use an IE of 0.8 km, which is the diameter of an average home range (Craighead and Craighead 1956).

Short-eared Owl: May use an IE of 0.9 km, which is based on an average breeding home range of 65 hectares.

Date: 26Feb2005
Author: Cannings, S., and G. Hammerson
Notes: Contains owls in the genera Otus, Glaucidium, Aegolius, Asio and Athene.

Use Class: Nonbreeding
Minimum Criteria for an Occurrence: Evidence of recurring presence of wintering individuals (including historical); and potential recurring presence at a given location. Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 20 days annually. Be cautious about creating EOs for observations that may represent single events.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance larger than three times the diameter of an average home range for these volant species; based the diameter of larger home ranges of males, e.g. those of Northern Pygmy-Owls: in Washington 170-230 hectares (A. Giese, pers. comm., cited in Holt and Petersen 2000); in Sweden, averaged 231 hectares (Kullberg 1995).
Whiskered Screech-Owls had home ranges about 1550 meters long, along permanent creek (Gehlbach and Gehlbach 2000).

Inferred Minimum Extent of Habitat Use (when actual extent is unknown): .6 km
Inferred Minimum Extent Justification: Conservatively based on a home range of 27 hectares; for example, a breeding male Northern Saw-whet Owl spent most of its active time in a 27-hectare core area (Cannings 1987).
Date: 16Apr2002
Author: Cannings, S.

Use Class: Roost
Minimum Criteria for an Occurrence: Evidence of recurring, nonbreeding, communal roosting at a given location; reliable observation of multiple individuals roosting in a distinct habitat patch in multiple years. To avoid creating EOs for ephemeral situations, there should be evidence of communal roosting over at least two different (though not necessarily consecutive) nonbreeding seasons.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance is arbitrary. Pertinent biologically based separation criteria do not exist.
Date: 25Oct2012
Author: Hammerson, G.
Population/Occurrence Viability
Help
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Help
Authors/Contributors
Help
NatureServe Conservation Status Factors Edition Date: 01Jan1996
NatureServe Conservation Status Factors Author: Reichel, J.D.
Element Ecology & Life History Edition Date: 31Mar1995
Element Ecology & Life History Author(s): HAMMERSON, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
Help
  • Alaska Department of Fish and Game. http://www.adfg.state.ak.us/pubs/notebook/bird/borealow.php. Alaska, USA. 2006.

  • American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.

  • American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.

  • Andersen, M.D. 2011. Maxent-based species distribution models. Prepared by Wyoming Natural Diversity Database for use in the pilot WISDOM application operational from inception to yet-to-be-determined date of update of tool.

  • Andersen, M.D. and B. Heidel. 2011. HUC-based species range maps. Prepared by Wyoming Natural Diversity Database for use in the pilot WISDOM application operational from inception to yet-to-be-determined date of update of tool.

  • Aquin, P. 1999. Évaluation de la situation des groupes taxonomiques des oiseaux du Québec. Ministère de l'Environnement et de la Faune. 13 pages.

  • Arsenault, D. P., P. B. Stacey, and G. A. Hoelzer. 2005. Mark-recapture and DNA fingerprinting data reveal high breeding-site fidelity, low natal philopatry, and low levels of population genetic differentiation in flammulated owls (Otus flammeolus). Auk 122:329-337.

  • B83COM01NAUS - Added from 2005 data exchange with Alberta, Canada.

  • BEAUVAIS, G.P. 1999. VERTEBRATES OF CONSERVATION CONCERN ON THE PITCHFORK RANCH. Unpublished report for the Pitchfork Ranch by WYNDD-University of Wyoming, Laramie, WY.

  • Bent, A. C. 1938. Life histories of North American birds of prey. Part 2. U.S. Nat. Mus. Bull. 170. 482 pp., 92 pls.

  • Bighorn National Forest. 1996. Endangered and Sensitive animal species of the Bighorn National Forest. Unpublished draft report on file at Bighorn NF Supervisor's Office, Sheridan, Wyoming.

  • Bull, E.L. 1987. Capture techniques for owls. Pages 291-293 in R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, editors. Biology and conservation of northern forest owls. USDA Forest Service, Gen. Tech. Rep. RM-142.

  • Cadman, M. D., P. F. J. Eagles, and F. M. Helleiner. 1987. The Atlas of Breeding Birds of Ontario. University of Waterloo Press, Waterloo, Canada. 617pp.

  • Campbell, R. W., N. K. Dawe, I. McTaggart-Cowan, J. M. Cooper, G. W. Kaiser, and M. C. McNall. 1990b. The birds of British Columbia. Volume 2. Nonpasserines: diurnal birds of prey through woodpeckers. University of British Columbia Press, Vancouver, B.C. 636 pp.

  • Cannings, R. J. 1987. The breeding biology of Northern Saw-whet Owls in southern British Columbia. Pages 193-198 IN Nero, R.W., R. J. Clark, R. J. Knapton, and H. Hamre, editors. Biology and conservation of northern forest owls. USDA For. Serv. Gen. Tech. Rep. RM-142, USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO.

  • Cannings, R. J. 1993. Northern Saw-whet Owl (Aegolius acadicus). No. 42 IN A. Poole and F. Gill, editors. The birds of North America. The Academy of Natural Sciences, Philadelphia; The American Ornithologists' Union, Washington, DC. 20pp.

  • Catling, P. M. 1972. A study of the Boreal owl in southern Ontario with particular reference to the irruption of 1968- 69. The Canadian Field-Naturalist 86:223-232.

  • Clark, Kathleen A. 1994. Habitat use and factors affecting vocalizations of owls in Western Wyoming, M.S. Thesis. Department of Zoology and Physiology, University of Wyoming.

  • Clark, R. J., D. G. Smith, and L. H. Kelso. 1978. Working bibliography of owls of the world. National Wildlife Federation, Sci. & Tech. Ser. No. 1. 336 pp.

  • Clark, T.W., A.H. Harvey, R.D. Dorn, D.L. Genter, and C. Groves, eds. 1989. Rare, sensitive and threatened species of the Greater Yellowstone Ecosystem. Northern Rockies Conservation Cooperative, Montana Natural Heritage Program, The Nature Conservancy, and Mountian West Environmental Services.

  • Desrosiers A., F. Caron et R. Ouellet. 1995. Liste de la faune vertébrée du Québec. Les publications du Québec. 122

  • Dionne C. 1906. Les oiseaux de la province de Québec. Dussault et Proulx.

  • Dorn, Jane L. and R.D. Dorn. 1990. Wyoming Birds. Mountain West Publishing, Cheyenne.

  • Duncan, J., and P. Duncan. 1994/95. Nocturnal owl surveys. Bird Trends (Canadian Wildlife Service) (4):24-25.

  • Eckert, Allan W. 1978. The Owls of North America. Weather-vane Books, New York. 278 pp.

  • Erskine, A. J. 1992. Atlas of breeding birds of the Maritime Provinces. Nimbus Publishing and the Nova Scotia Museum, Halifax, Nova Scotia.

  • Finch, D.M. 1992. Threatened, endangered, and vulnerable species of terrestrial vertebrates in the Rocky Mountain Region. General Technical Report RM-215. USDA, Forest Service, Rocky Mountain Forest and Range Experiment Station, Ft. Collins CO. 38 p.

  • Fisher, A.K. 1893. The hawks and owls of the United States in their relation to agriculture. Washington U.S. Dept. of Agriculture Bull. no. 6. 210 pp.

  • Gamel, C. M. 1997. Habitat selection, population density, and home range of the elf owl, Micrathene whitneyi, at Santa Ana National Wildlife Refuge, Texas. M.S. thesis, University of Texas-Pan American, Edinburg, Texas.

  • Garber, C.S., R.L. Wallen and K. Duffy. 1991. Distribution of boreal owl observation records in Wyoming. Journal of Raptor Research 25(4):120-122.

  • Gehlbach, F. R., and N. Y. Gehlbach. 2000. Whiskered Screech-Owl (Otus trichopsis). No. 507 IN A. Poole and F. Gill, editors. The birds of North America. The Birds of North America, Inc., Philadelphia. 24pp.

  • Godfrey, W. E. 1986. The birds of Canada. Revised edition. National Museum of Natural Sciences, Ottawa. 596 pp. + plates.

  • Goggans, R. 1986. Habitat use by flammulated owls in northeastern Oregon. Master's thesis, Oregon State University, Corvallis, OR.

  • Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.

  • Hayward, G. D., P. H. Hayward, and E. O. Garton. 1987a. Revised breeding distribution of the boreal owl in the northern Rocky Mountains. Condor 89:431-432.

  • Hayward, G. D., R. K. Steinhosrt and P. H. Hayward. 1992. Monitoring boreal owl populations with nest boxes: Sample size and cost. J. Wildl. Manage. 56:777-785.

  • Hayward, G. D., R. K. Steinhosrt and P. H. Hayward. 1992. Monitoring boreal owl populations with nest boxes: Sample size and cost. J. Wildl. Manage. 56:777-785.

  • Hayward, G. D., and J. Verner, editors. 1994. Flammulated, boreal, and great gray owls in the United States: a technical conservation assessment. USDA Forest Service, General Technical Report RM-253. Fort Collins, Colorado.

  • Hayward, G. D., and P. H. Hayward. 1993. Boreal Owl (AEGOLIUS FUNEREUS). In The Birds of North America, No. 63. A. Poole and F. Gill, (eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.

  • Hayward, G. D., and P. H. Hayward. 1993. Boreal Owl (AEGOLIUS FUNEREUS). In The Birds of North America, No. 63. A. Poole and F. Gill, (eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.

  • Hayward, G. D., et al. 1987b. Movements and home range use by boreal owls in central Idaho. Pages 175-184 in Nero, R. W., et al., eds. Biology and conservation of northern forest owls. USDA For. Serv., Gen. Tech. Rep. RM-142.

  • Hayward, G.D. and P.H. Hayward. 1993. Boreal Owl (AEGOLIUS FUNEREUS). IN: Poole, A. and F. Gill, eds. The Birds of North America. The Academy of Natural Sciences and the American Ornithologists' Union, Philadelphia and Washington, D.C.

  • Hayward, G.D., P.H Hayward, and E.O. Garton. 1993. Ecology of boreal owls in the northern Rocky Mountains, U.S.A. IN: Kirkpatrick, R.L., ed. Wildlife Monographs, No. 124. The Wildlife Society.

  • Herren, Vicki A. 1994. Boreal Owl mating habitat in Wyoming's Sierra Madres. M.S. Thesis. Department of Zoology and Physiology.

  • Holt, D. W., and D. Ermatinger. 1989. First confirmed nest site of boreal owls in Montana. Northwest. Nat. 70:27-31.

  • Holt, D. W., and J. L. Petersen. 2000. Northern Pygmy-Owl (Glaucidium gnoma). No. 494 IN A. Poole and F. Gill, eds. The birds of North America. The Birds of North America, Inc., Philadelphia, PA. 24pp.

  • Jankovsky-Jones, M., G. Jones, and W. Fertig. 1995. Ecological evaluation for the potential East Fork Encampment River Research Natural Area within the Medicine Bow National Forest, Carbon County, Wyoming. Unpublished report prepared for the Medicine Bow National Forest by the Wyoming Natural Diversity Database, Laramie, WY.

  • Jankovsky-Jones, M., G. Jones, and W. Fertig. 1995. Ecological evaluation for the potential Ground Moraine Research Natural Area within the Medicine Bow National Forest, Albany County, Wyoming. Unpublished report prepared for the Medicine Bow National Forest by the Wyoming Natural Diversity Database, Laramie, WY.

  • Johnsgard, P. 1988. North American owls: biology and natural history. Smithsonian Inst. Press. 336 pp.

  • Kirk, D. A., D. Hussell, and E. Dunn. 1995. Raptor population status and trends in Canada. Bird Trends (Canadian Wildlife Service) 4:2-9.

  • Kirk, D.A. 1995. Status report on the Boreal Owl, Aegolius funereus, in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 24 pp.

  • Kullberg, C. 1995. Strategy of the Pygmy Owl while hunting avian and mammalian prey. Ornis Fenn. 72:72-78.

  • Lagacé M., L. Blais et D. Banville. 1983. Liste de la faune vertébrée du Québec. Première édition. Ministère du Loisir, de la Chasse et de la Pêche. 100

  • Linkhart, B. D. 1984. Range, activity, and habitat use by nesting flammulated owls in a Colorado ponderosa pine forest. Masters thesis, Colorado State University, Fort Collins, CO.

  • McAtee W.L. 1959. Folk - names of candian birds. National Museum of Canada. Folk - names of candian birds. National Museum of Canada. 74 pages.

  • Merrill, E.H., T.W. Kohley, and M.E. Herdendorf. 1996. Wyoming Gap Analysis terrestrial vertebrate species map atlas. Wyoming Cooperative Fish and Wildlife Unit, University of Wyoming, Laramie WY. 982 pp. in 2 volumes.

  • Mills, S. and M. Neighbours. 1995. Intensive data gathering project (fine-filter analysis) for occurrences of rare, threatened, endangered and sensitive species in sections M331H and M331I, north central highlands and northern parks and ranges, in Wyoming. Unpublished report prepared for Medicine Bow National Forest by the Wyoming Natural Diversity Database, Laramie, WY. 294 pp.

  • Nicholls, T. H., and M. R. Fuller. 1987. Owl telemetry techniques. Pages 294-301 IN R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, editors. Biology and conservation of northern forest owls. USDA Forest Service, Gen. Tech. Rep. RM-142.

  • O'Connell, M. W. 1987. Occurrence of the boreal owl in northeastern Washington. Pages 185-188 in Nero, R. W., et al., eds. Biology and conservation of northern forest owls. USDA For. Serv., Gen. Tech. Rep. RM-142.

  • Oakleaf B., A. Cerovski, and B. Luce. 1997. Interim Completion Report -Sensitive Species Inventory. Wyoming Game & Fish Department, Lander, WY. 31pp.

  • Oakleaf, B, B. Luce, S. Ritter and A. Cerovski, eds. 1992. Wyoming bird and mammal atlas. Wyoming Game and Fish Department, Game Division, Biological Services; Cheyenne, WY. 170 p. + 1994 addendum.

  • Ouellet H., M. Gosselin et J.P. Artigau. 1990. Nomenclature française des oiseaux d'Amérique du Nord. Secrétariat d'État du Canada. 457 p.

  • Palmer, D. A. 1987. Annual, seasonal, and nightly variation in calling activity of boreal and northern saw-whet owls. Pp. 162-168 in Nero, R.W., et al., eds. Biol. & Cons. of n. forest owls. U.S. For. Serv., Gen. Tech Rep. RM-142.

  • Palmer, D. A., and R. A. Ryder. 1984. The first documented breeding of the boreal owl in Colorado. Condor 86:215-217.

  • Parks Canada. 2000. Vertebrate Species Database. Ecosystems Branch, 25 Eddy St., Hull, PQ, K1A 0M5.

  • Pendleton, B. A. G., B. A. Millsap, K. W. Cline, and D. M. Bird. 1987. Raptor management techniques manual. National Wildlife Federation, Sci. and Tech. Ser. No. 10. 420 pp.

  • Proudfoot, G. A., and R. R. Johnson. 2000. Ferruginous Pygmy-Owl (Glaucidium brasilianum). No. 498 IN A. Poole and F. Gill (eds.), The birds of North America. The Birds of North America, Inc. Philadelphia, PA. 20pp.

  • Rashid, S. 1999. Northern Pygmy Owls in Rocky Mountain National Park. Colorado Field Ornithol. 33:94-101.

  • Rodrick, E. and R. Milner (eds). 1991. Management recommendations for Washington's priority habitats and species. Wash. Dept. Wildl., Olympia. [Unpubl. Rep.]

  • Rodrick, E. and R. Milner (eds). 1991. Management recommendations for Washington's priority habitats and species. Wash. Dept. Wildl., Olympia. [Unpubl. Rep.]

  • Ryder, R. A., et al. 1987. Distribution and status of the boreal owl in Colorado. Pages 169-174 in Nero, R. W., et al., eds. Biology and conservation of northern forest owls. USDA For. Serv., Gen. Tech. Rep. RM-142.

  • Semenchuk, G.P. 1992. The atlas of breeding birds of Alberta. Federation of Alberta Naturalists. 391 pp.

  • Smith, D.G. 1987b. Owl census techniques. Pages 304-307 in R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, editors. Biology and conservation of northern forest owls. USDA Forest Service, Gen. Tech. Rep. RM-142.

  • Stahlecker, D. W., and J. J. Rawinski. 1990. First records for the boreal owl in New Mexico. Condor 92:517-519.

  • Stahlecker, D. W., and R. B. Duncan. 1996. The boreal owl at the southern terminus of the Rocky Mountains: undocumented longtime resident or recent arrival? Condor 98:153-161.

  • Stahlecker, D. W., and R. B. Duncan. 1996. The boreal owl at the southern terminus of the Rocky Mountains: undocumented longtime resident or recent arrival? Condor 98:153-161.

  • Swengel, S. R. 1990. How to find Saw-whet Owls. Bird Watcher's Digest 12:68-75.

  • Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.

  • Voous, K. H., and A. Cameron. 1989. Owls of the Northern Hemisphere. MIT Press, Cambridge, Massachusetts. 320 pp.

  • Whelton, B. D. 1989. Distribution of the boreal owl in eastern Washington and Oregon. Condor 91:712-716.

  • Wiens, T. P. 1989. Spring migrant boreal owls at Whitefish Point, Michigan. Jack-Pine Warbler 67:88-93.

  • Wyoming Game and Fish Department. 1998. Threatened, endangered, and nongame bird and mammal investigations: Annual completion report. Wyoming Game and Fish Department - Nongame Program, Biological Services Section. 299 p.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of November 2016.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2017 NatureServe, 4600 N. Fairfax Dr., 7th Floor, Arlington Virginia 22203, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.