Data Zone
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.
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.
| Critically Endangered | Endangered | Vulnerable |
|---|---|---|
| - | - | - |
| Year | Category | Criteria |
|---|---|---|
| 2024 | Least Concern | |
| 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 |
| Migratory status | full migrant | Forest dependency | high |
| Land-mass type | Average mass | - |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence (breeding/resident) | 1,290,000 km2 | |
| Extent of Occurrence (non-breeding) | 627,000 km2 | |
| Severely fragmented? | no | - |
| Estimate | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| Population size | unknown | - | - | - |
| Population trend | decreasing | - | suspected | - |
| Generation length | 1.98 years | - | - | - |
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). This species is considered to have a high dependency on forest habitat, and tree cover is estimated to have declined by 2.5% within its mapped range over the past 10 years (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). It is therefore tentatively suspected that this rate of cover loss may have led to a decline of between 1-19% in the species' population size over the same time frame, with a best estimate of reduction being less than 5%.
Trend justification: .
| Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
|---|---|---|---|---|---|---|
| Cambodia | extant | native | yes | |||
| China (mainland) | extant | native | ||||
| Laos | extant | native | yes | |||
| Malaysia | extant | vagrant | yes | |||
| Myanmar | extant | native | yes | |||
| Thailand | extant | native | yes | |||
| Vietnam | extant | native | yes |
| Country/Territory | IBA Name |
|---|
| 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 (2024) Species factsheet: Alström's Warbler Phylloscopus soror. Downloaded from
https://datazone.birdlife.org/species/factsheet/alstroms-warbler-phylloscopus-soror on 04/12/2024.
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 04/12/2024.