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

Taxonomic note
Hypotaenidia okinawae (del Hoyo and Collar 2014) was previously placed in the genus Gallirallus.

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	B1ab(ii,iii,v); C2a(ii)	A2bce+3bce+4bce; B1ab(ii,iii,v); C1+2a(i,ii); D1+2

Red List history

Year	Category	Criteria
2021	Endangered	B1ab(ii,iii,v); C2a(ii)
2016	Endangered	B1ab(i,ii,iii,v);C2a(ii)
2013	Endangered	B1ab(i,ii,iii,v);C2a(ii)
2012	Endangered	B1ab(i,ii,iii,v);C2a(ii)
2008	Endangered	B1a+b(i,ii,iii,v); C2a(ii)
2006	Endangered
2004	Endangered
2000	Endangered
1996	Endangered
1994	Endangered
1988	Threatened

Migratory status	not a migrant	Forest dependency	medium
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	990 km2	medium
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	480 mature individuals	good	estimated	2006
Population trend	decreasing	good	estimated	2011-2026
Rate of change over the past 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Generation length	4.7 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Surveys conducted between 1996 and 2004 estimated 717 individuals at the end of the period. Repeat surveys in 2006 found no further decrease (K. Ozaki in litt. 2006). On this basis the population is estimated at c.720 individuals, equivalent to c.480 mature individuals.

Trend justification: Hanawa and Morishita (1986) estimated the population to be c.900 pairs or 1,500-2,100 birds. Ozaki et al. (2006) reported a reduction to 717 individuals by 2004 (with no further decline by 2006). Hence, a decline of 37% occurred over ten years and the negative population trend is therefore best placed in the band 30-49%, and considered on-going.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Japan	extant	native	yes

Country/Territory	IBA Name
Japan	Yambaru, northern Okinawa forest

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Arable Land	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	major	resident
Wetlands (inland)	Permanent Freshwater Marshes/Pools (under 8ha)	major	resident
Altitude	0 - 500 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	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Boiga irregularis	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Causing/Could cause fluctuations		Low Impact: 3
		Stresses Species disturbance, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Canis familiaris	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Corvus macrorhynchos	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Herpestes javanicus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Mustela itatsi	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species disturbance, Reduced reproductive success, Species mortality
Natural system modifications	Dams & water management/use - Dams (size unknown)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Tourism & recreation areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Okinawa Rail Hypotaenidia okinawae. Downloaded from https://datazone.birdlife.org/species/factsheet/okinawa-rail-hypotaenidia-okinawae on 22/12/2024.
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 22/12/2024.