EN
Okinawa Rail Hypotaenidia okinawae



Taxonomy

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. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- B1ab(i,ii,iii,v);C2a(ii) A2bce+3bce+4bce;B1ab(i,ii,iii,v);C2a(i,ii);D1+2

Red List history
Year Category Criteria
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
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 990 medium
Number of locations 1 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 480 good estimated 2006
Population trend Decreasing good estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 1 - - -
Largest subpopulations 100 - - -
Generation length (yrs) 3.4 - - -

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 (Ozaki in litt. 2006). On this basis the population is estimated at c.720 individuals, equivalent to c.480 mature individuals. Brazil (2009) estimates the population of Japan to number c.100-10,000 breeding pairs.

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 distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Japan N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Japan Yambaru, northern Okinawa forest

Habitats & altitude
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  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting 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 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 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 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 Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Reduced reproductive success
Natural system modifications Dams & water management/use 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

Recommended citation
BirdLife International (2019) Species factsheet: Hypotaenidia okinawae. Downloaded from http://www.birdlife.org on 15/09/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/09/2019.