VU
Pleske's Grasshopper-warbler Helopsaltes pleskei



Taxonomy

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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - C2a(i)

Red List history
Year Category Criteria
2016 Vulnerable C2a(i)
2012 Vulnerable C2a(i)
2008 Vulnerable C2a(i)
2004 Vulnerable
2000 Vulnerable
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Land-mass type - shelf island
Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,080,000 medium
Extent of Occurrence non-breeding (km2) 29,100 medium
Number of locations 11-100 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 2500-9999 poor estimated 2000
Population trend Decreasing poor 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) 10-19 - - -
Decline (10 years/3 generation past and future) 10-19 - - -
Number of subpopulations 2-100 - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 3.7 - - -

Population justification: The global population size is 'unlikely to be much more than a few thousand individuals' (BirdLife International 2001), while national population estimates include: < c.100 breeding pairs and < c.1,000 individuals on migration in China; < c.50 individuals on migration and < c.50 wintering individuals in Taiwan; c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Korea; c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Japan and c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Russia (Brazil 2009). The total population is placed in the band 2,500-9,999 mature individuals, equating to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.

Trend justification: Various human activities are negatively affecting both breeding and wintering habitats for this species, suggesting that moderate population declines are likely to be continuing.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
China (mainland) N Extant Yes Yes
Hong Kong (China) N Extant Yes
Japan N Extant Yes
North Korea V Extant
Russia N Extant Yes
Russia (Asian) N Extant Yes
South Korea N Extant Yes
Vietnam N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Hong Kong (China) Inner Deep Bay and Shenzhen River catchment area
Japan Oshima island
Japan Toshima island
Japan Niijima and Shikinejima Islands
Japan Kozushima island
Japan Miyakejima island
Japan Mikurajima island
Japan Hachijojima island
Japan Aogashima island
Japan Okinoshima and Koyajima islets
Japan Kii Nagashima islets
Japan Hakata bay
Japan Tsukuejima islets
Japan Danjo islands
Japan Tsushima islands
Japan Birojima islet
Japan Okikojima islet
Japan Koshikijima islands
Russia (Asian) Islands in Peter the Great bay
South Korea Chilbal-do island
South Korea Kukul-do island

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Shrubland Subtropical/Tropical Dry major breeding
Shrubland Temperate major breeding
Wetlands (inland) Bogs, Marshes, Swamps, Fens, Peatlands major non-breeding
Altitude 0 - 350 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Geological events Volcanoes Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Very Rapid Declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion
Pollution Domestic & urban waste water - Type Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Reduced reproductive success, Species mortality
Residential & commercial development Tourism & recreation areas Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species disturbance, Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2022) Species factsheet: Helopsaltes pleskei. Downloaded from http://www.birdlife.org on 26/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/06/2022.