EN
Japanese Night-heron Gorsachius goisagi



Taxonomy

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
- C2a(i) A2cde+3cde+4cde; C2a(i); D1

Red List history
Year Category Criteria
2016 Endangered C2a(i)
2012 Endangered C2a(i)
2008 Endangered C2a(i)
2004 Endangered
2000 Endangered
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status full migrant Forest dependency High
Land mass type Land-mass type - continent
Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 631,000 medium
Extent of Occurrence non-breeding (km2) 888,000 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 600-1700 poor estimated 2007
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) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2-100 - - -
Largest subpopulations - - -
Generation length (yrs) 6.7 - - -

Population justification: Recent work in Japan suggests the previous assertion that the global population comprises fewer than 1,000 individuals may have been overly pessimistic (although Brazil 2009 estimated fewer than 100 breeding pairs, fewer than 50 individuals on migration and fewer than 50 wintering individuals in Japan). Hence, the true figure probably lies within the band 1,000-2,499 individuals. This equates to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification: Rapid declines in the past are suspected to be on-going, mainly owing to forest loss and changing agricultural practices.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Indonesia Tangkoko Dua Sudara
Indonesia Mahawu - Masarang
Philippines University of the Philippines Land Grants (Pakil and Real)
Philippines Quezon National Park
Philippines Victoria and Anepahan Ranges
Philippines Central Panay mountains
Philippines Cuernos de Negros
Philippines Mount Bandila-an
Philippines Mount Hilong-hilong
Philippines Mount Kampalili-Puting Bato
Philippines Mount Hamiguitan (Tumadgo peak)
Philippines Liguasan marsh
Philippines Mount Busa-Kiamba
Philippines Mount Latian complex
Philippines Pasonanca watershed
Russia (Asian) Lower Tumen river
Philippines Mount Malindang
Japan Hachirogata
Japan Mount Hyonosen
Indonesia Morowali

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Arable Land suitable non-breeding
Forest Subtropical/Tropical Dry suitable non-breeding
Forest Subtropical/Tropical Dry suitable breeding
Forest Subtropical/Tropical Moist Lowland major breeding
Forest Subtropical/Tropical Moist Lowland major non-breeding
Forest Subtropical/Tropical Moist Montane major non-breeding
Forest Subtropical/Tropical Moist Montane major breeding
Forest Temperate major breeding
Wetlands (inland) Bogs, Marshes, Swamps, Fens, Peatlands suitable non-breeding
Altitude 0 - 2400 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Shifting agriculture Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
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
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation
Geological events Volcanoes Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Rapid Declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mustela sibirica 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 - Unspecified species Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success
Residential & commercial development Commercial & industrial areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Housing & urban areas 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 (2020) Species factsheet: Gorsachius goisagi. Downloaded from http://www.birdlife.org on 02/12/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 02/12/2020.