• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2020	Near Threatened	A2abce+3bce+4abce
2017	Near Threatened	A2abce+3bce+4abce; C2a(i)
2016	Near Threatened	C2a(i)
2013	Near Threatened	C2a(i)
2012	Near Threatened	C2a(i)
2008	Near Threatened	C2a(i)
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Lower Risk/Near Threatened
1988	Threatened

Migratory status	altitudinal migrant	Forest dependency	high
Land-mass type	continent	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,920,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	15000 mature individuals	medium	estimated	2003
Population trend	decreasing	good	inferred	2003-2025
Rate of change over the past 10 years/3 generations (longer of the two periods)	20-29%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	20-29%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	20-29%	-	-	-
Generation length	7.09 years	-	-	-

Population justification: Its population size was estimated at c.15,000 mature individuals (Rich et al. 2004). However, this has likely declined in recent years and population surveys are urgently required to accurately quantify the population size of this species.

Trend justification: There has been no direct estimation of the overall population trend for this species but it is suspected to have undergone considerable declines. Subspecies caurina is estimated to be in significant decline, at 3.8% per year range-wide and 8.4% per year in Washington State (1985-2013; Dugger et al. 2016). The New Mexico population of subspecies lucida is estimated to be declining at 6% per year (B. Bird in litt. 2011), while the species may have declined by c.50% between 1990 and 2012 in the Sierra Nevada (Tempel et al. 2014b). Whilst declines are rapid in a number of locations however, the species appears stable in some areas, such as Arizona (B. Bird in litt. 2011) and for subspecies huachucae, Mexico, where forestry activities typically modify rather than destroy habitat (Lammertink et al. 1996, J. M. Lammertink in litt. 1998); subspecies huachucae may actually be exhibiting localised increases in some subpopulations throughout New Mexico (Ganey et al. 2014b). Despite this however, the overall population is still suspected to be in considerable decline owing primarily to on-going habitat disturbance by inappropriate silvicultural management including clear-felling and degradation (del Hoyo et al. 1999). There has been no direct estimation of the overall rate of decline, but the species is conservatively assessed as declining at a rate at least approaching the threshold for Vulnerable, a conclusion supported by Partners in Flight (2019) (7-26.9% across three generations), and as such is placed in the range 20-29% over 3 generations (c.21.3 years).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Canada	extant	native	yes
Mexico	extant	native	yes
USA	extant	native	yes

Country/Territory	IBA Name
Mexico	Mesa de Guacamayas
Mexico	San Antonio Peña Nevada
Mexico	Sierra de San Carlos
Mexico	Sierra de Valparaíso
Mexico	Sierra Fría
Mexico	Sierra Maderas del Carmen
Mexico	Sistema de Sierras de la Sierra Madre Occidental
Mexico	Tancítaro
USA	Canyonlands Area
USA	Chiricahua Mountains, Coronado National Forest
USA	Grand Canyon National Park- Raptor Migration Points
USA	Zion National Park UT20

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Boreal	suitable	resident
Forest	Subtropical/Tropical Dry	marginal	resident
Forest	Temperate	major	resident
Altitude	0 - 2700 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Droughts	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion, Reduced reproductive success
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Negligible declines		Low Impact: 3
		Stresses Reduced reproductive success
Energy production & mining	Oil & gas drilling	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance	Recreational activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Phytophthora ramorum	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Plasmodium relictum	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Strix varia	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Hybridisation, Competition
Invasive and other problematic species, genes & diseases	Viral/prion-induced diseases - West Nile Virus (WNV)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species mortality
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Utility & service lines	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion, Species mortality

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Spotted Owl Strix occidentalis. Downloaded from https://datazone.birdlife.org/species/factsheet/spotted-owl-strix-occidentalis on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/11/2024.