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

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
-	-	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

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,080,000 km2	medium
Extent of Occurrence (non-breeding)	29,100 km2	medium
Number of locations	11-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2500-9999 mature individuals	poor	estimated	2000
Population trend	decreasing	poor	suspected	2011-2022
Rate of change over the past 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	3.7 years	-	-	-
Number of subpopulations	2-100	-	-	-

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	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
China (mainland)	extant	native		yes		yes
Hong Kong (China)	extant	native			yes
Japan	extant	native		yes
North Korea	extant	vagrant
Russia	extant	native		yes
Russia (Asian)	extant	native		yes
South Korea	extant	native		yes
Vietnam	extant	native			yes

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

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

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

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Recommended citation
BirdLife International (2024) Species factsheet: Pleske's Grasshopper-warbler Helopsaltes pleskei. Downloaded from https://datazone.birdlife.org/species/factsheet/pleskes-grasshopper-warbler-helopsaltes-pleskei 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.