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

Taxonomic note

Troglodytes troglodytes, T. pacificus and T. hiemalis (del Hoyo and Collar 2016) were previously lumped as T. troglodytes following AERC TAC (2003), AOU (1998 & supplements), Cramp et al. (1977-1994), Sibley & Monroe (1990, 1993) and Stotz et al. (1996).

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2021	Least Concern
2016	Least Concern
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	full migrant	Forest dependency	medium
Land-mass type		Average mass	9 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	9,680,000 km2	medium
Extent of Occurrence (non-breeding)	9,920,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	7500000 mature individuals	poor	inferred	2019
Population trend	decreasing	-	inferred	-
Rate of change over the past 10 years/3 generations (longer of the two periods)	6%	-	-	-
Generation length	2.07 years	-	-	-

Population justification: The global population is inferred to number 7,500,000 mature individuals (Partners in Flight 2019).

Trend justification:

The species has been undergoing a moderate decline at an average rate of 0.6% per year between 1970 and 2017 (Partners in Flight 2019). Short-term trends from the North American Breeding Bird Survey (BBS) suggest increasingly negative population trajectories and a half-life of 15 years (Pardieck et al. 2018). BBS data are however not considered representative for this species and moreover, the population is known to fluctuate considerably depending on climatic conditions in winter (Toews and Irwin 2020; see also trends from Pardieck et al. 2018). Therefore, it is here assumed that the overall population declines are closer to the long-term trend reported by Partners in Flight (2019), amounting to 6% over ten years.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Rural Gardens	suitable	breeding
Artificial/Terrestrial	Rural Gardens	suitable	non-breeding
Artificial/Terrestrial	Urban Areas	suitable	breeding
Artificial/Terrestrial	Urban Areas	suitable	non-breeding
Forest	Boreal	major	breeding
Forest	Subtropical/Tropical Moist Lowland	suitable	breeding
Forest	Subtropical/Tropical Moist Lowland	suitable	non-breeding
Forest	Temperate	major	breeding
Forest	Temperate	major	non-breeding
Shrubland	Boreal	suitable	breeding
Shrubland	Boreal	suitable	non-breeding
Shrubland	Temperate	suitable	breeding
Shrubland	Temperate	suitable	non-breeding
Altitude		Occasional altitudinal limits

Purpose	Scale
Food - human	subsistence, national
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Pacific Wren Troglodytes pacificus. Downloaded from https://datazone.birdlife.org/species/factsheet/pacific-wren-troglodytes-pacificus on 22/12/2024.
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 22/12/2024.