Justification of Red List category
This species has a large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence under 20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (under 10,000 mature individuals with a continuing decline estimated to be over 10% in ten years or three generations, or with a specified population structure). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (over 30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern.
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 (Brazil 2009). This species is considered to have a high dependency on forest habitat, and tree cover is estimated to have declined by 5.9% 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 5-9%.
Trend justification
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This species has a large range in eastern China and northern Myanmar, Laos and Vietnam.
The species inhabits broadleaved evergreen forest and secondary growth, typically breeding from 1,750 up to at least 1,900 m, and wintering down to 450 m (Robson 2000).
Text account compilers
Rutherford, C.A.
Recommended citation
BirdLife International (2024) Species factsheet: Bianchi's Warbler Phylloscopus valentini. Downloaded from
https://datazone.birdlife.org/species/factsheet/bianchis-warbler-phylloscopus-valentini on 22/11/2024.
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 22/11/2024.