Boreal Owl (Richardson's Owl)

Aegolius funereus

General Status Rank: 
Secure
ELCODE: 
ABNSB15010
Common Name: 
Boreal Owl (Richardson's Owl)
Scientific Name: 
Aegolius funereus
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Taxonomy
Group: 
Bird
Kingdom: 
Animalia
Phylum: 
Chordata
Class: 
Aves
Order: 
Strigiformes
Family: 
Strigidae
References: 
B004
General Biology
Canada Known Subspecies Count: 
0

Female Age at Maturity

1 year)R060); Except in years of reduced food availability, both sexes can breed the year after hatching, but a larger proportion of females than males breed their first year (Korpimaki 1988c).(B145)
References: 
R060
B145
Reproduction Frequency Per Year: 
0
Habitat
nest in tree cavity made by pileated woodpeckers, and/or northern flickers; forests dominated by black spruce, white spruce, balsam fir, balsam poplar, white birch, and especially trembling aspen
References: 
B004
H126
R060
Distribution

Ecozones

Taiga Cordillera, Taiga Plains, Taiga Shield, Boreal Cordillera, Boreal Plains
References: 
B004

Distribution

0.609; Fairly common permanent resident in forested regions of the Territory. Ranging northwards, at least occasionally, to Inuvik, Aklavik and Colville Lake. Some likely disperse southwards during winter.(NWT Bird checklist project)
Score: 
G
References: 
R060
Winter Distribution Description: 
withdraws from northernmost range

Number of Occurrences

Probably more than 100 as widespread species in NWT
Score: 
DE
References: 
H126

Area of Occupancy

irruptive movements on a 3 - 4 year cyclic basis (probably coinciding with vole popn crashes);App. Changing distribution due to movement after microtine popn cycles - dist. assumed stable in general
Score: 
-
References: 
R060
B145
Population

Population Size

likely abundant in breeding range; prob. Less than 10 00 and more than 1000 (unkown)
Score: 
DE
References: 
H126
R060

Density

2 to 15 calling males per 100 square kilometers
Trends

Trends

Fluctuations on a 3 - 4 year cyclic basis (probably coinciding with vole popn crashes) (R060); Reliable indication of long-term trends unavailable because of difficulty in surveying and censusing; further complicated by nomadism and fluctuating prey populations. (B145)
References: 
R060
B145
Threats

Threats

low food supply, few nest cavities, forest management resulting in less snags; threats are limited in NWT
Score: 
C
References: 
H126
R060

Intrinsic Vulnerability

Forest management resulting in less snags, forestry; threats limited in NWT
Score: 
-
References: 
H126
R060
General Status Rank
Rank: 
Secure
Status Rank Description: 
But need data on numbers and trends
S Rank: 
S4?
Decision Process Description: 
Drafted by Suzanne Carriere based on printed references. Reviewed in 2005 by S Carriere, no change in status; Reviewed in 2010;no change; Reviewed in 2015, no change; Reviewed in 2020, no change
Last Updated: 
June 30, 2020
Status Designations

Canada – Assessment by Committee on the Status of Endangered Wildlife in Canada

COSEWIC Status: 
Not At Risk

References

Age Of Maturity

  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return
  • Hayward, G. D. and P. H. Hayward. 1993. (1993) Boreal Owl (Aegolius funereus).. Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union. In The Birds of North America, No. 63 (A. Poole and F. Gill, Eds.). - B145 Return

Area of Occupancy

  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return
  • Hayward, G. D. and P. H. Hayward. 1993. (1993) Boreal Owl (Aegolius funereus).. Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union. In The Birds of North America, No. 63 (A. Poole and F. Gill, Eds.). - B145 Return

Ecozones

  • Godfrey WE (1986) The Birds of Canada. National Museums of Canada Revised Edition RWED Library Call #QL685.G6 - B004 Return

Habitat

  • Godfrey WE (1986) The Birds of Canada. National Museums of Canada Revised Edition RWED Library Call #QL685.G6 - B004 Return
  • Carrière, S. (2000) Pers. communication. Ecosystem Management Biologist; RWED - H126 Return
  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return

Intrinsic Vulnerability

  • Carrière, S. (2000) Pers. communication. Ecosystem Management Biologist; RWED - H126 Return
  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return

NWT Known Subspecies

Godfrey WE (1986) The Birds of Canada. National Museums of Canada Revised Edition RWED Library Call #QL685.G6 - B004 Return

Number of Occurrences

  • Carrière, S. (2000) Pers. communication. Ecosystem Management Biologist; RWED - H126 Return

Population Size

Carrière, S. (2000) Pers. communication. Ecosystem Management Biologist; RWED - H126 Return
,
Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return

Range Extent

  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return

Short Term Trends

  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return
  • Hayward, G. D. and P. H. Hayward. 1993. (1993) Boreal Owl (Aegolius funereus).. Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union. In The Birds of North America, No. 63 (A. Poole and F. Gill, Eds.). - B145 Return

Taxonomy

  • Godfrey WE (1986) The Birds of Canada. National Museums of Canada Revised Edition RWED Library Call #QL685.G6 - B004 Return

Threats

  • Carrière, S. (2000) Pers. communication. Ecosystem Management Biologist; RWED - H126 Return
  • Kirk DA (1995) Status report on the boreal owl Aegolius funereus in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC) RWED Library Folder - R060 Return