LC
Alström's Warbler Phylloscopus soror



Taxonomy

Taxonomic note
Phylloscopus soror (del Hoyo and Collar 2016) was previously listed as Seicercus soror.

Taxonomic source(s)
Alström, P.; Olsson, U. 1999. The golden-spectacled warbler: a complex of sibling species, including a previously undescribed species. Ibis 141: 545-568.
Alström, P.; Olsson, U. 1999. The golden-spectacled warbler: a complex of sibling species, including a previously undescribed species. Ibis 141: 545-568.
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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2006 Least Concern
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status full migrant Forest dependency High
Land mass type Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,290,000
Extent of Occurrence non-breeding (km2) 627,000
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals unknown not applicable not applicable 0
Population trend Stable suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Percentage in largest subpopulation - - -

Population justification: The global population size has not been quantified, but the species is described as locally common to abundant (del Hoyo et al. 2006), while the population in China has been estimated at c.100-10,000 breeding pairs and c.50-1,000 individuals on migration (Brazil 2009).

Trend justification: The population is suspected to be stable in the absence of evidence for any declines or substantial threats.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Cambodia N Extant Yes
China (mainland) N Extant
Laos N Extant Yes
Malaysia V Extant Yes
Myanmar N Extant Yes
Thailand N Extant Yes
Vietnam N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major non-breeding
Forest Temperate major breeding
Altitude 600 - 1500 m Occasional altitudinal limits  

Recommended citation
BirdLife International (2022) Species factsheet: Phylloscopus soror. Downloaded from http://www.birdlife.org on 06/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/12/2022.