Kozushima island

IBA Criteria

Year of most recent IBA criteria assessment: 2004

Populations of IBA trigger species
Species Current IUCN Red List Category Season Year(s) of estimate Population estimate IBA Criteria Triggered
Japanese Woodpigeon Columba janthina NT resident 2004 present A2
Tristram's Storm-petrel Hydrobates tristrami LC passage 2004 present A4ii
Japanese Murrelet Synthliboramphus wumizusume VU breeding 2004 present A1, A4ii
Pleske's Grasshopper-warbler Locustella pleskei VU breeding 2004 present A1
Ijima's Leaf-warbler Phylloscopus ijimae VU breeding 2004 present A1, A2
Izu Thrush Turdus celaenops VU resident 2004 present A1, A2

Note: This table presents the IBA criteria triggered and the species that triggered then at the time of assessment, the current IUCN Red List category may vary from that which was in place at that time.

For more information about the IBA assessment process and criteria please click here

IBA Monitoring

Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2015 low not assessed medium
Was the whole site covered? Yes State assessed by unset
Accuracy of information -

Threats to the site (pressure)
Threat Level 1 Threat Level 2 Timing Scope Severity Result
No known threats no known threats happening now whole area/population (>90%) no or imperceptible deterioration low

Conservation actions taken at site (response)
Conservation Designation Management Planning Conservation Action Result
Whole area of site (>90%) covered by appropriate conservation designation A comprehensive and appropriate management plan exists that aims to maintain or improve the populations of qualifying bird species Some limited conservation initiatives are in place medium
For more information about IBA monitoring please click here

IBA Protection

Protection status:

Protected Area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)
Tadanaejima 国指定鳥獣保護区 593 protected area overlaps with site 0
Onoharajima 国指定鳥獣保護区 546 protected area is adjacent to site 0
Fuji hakone izu 国立公園 166,767 protected area overlaps with site 1,848
Common fishery right area(Tokyo) 共同漁業権区域 102,714 protected area is adjacent to site 0


IUCN Habitat Habitat detail Extent (% of site)
Forest -
Coastline Rock stacks and islands -
For further information about the habitat classification please click here.

Recommended citation
BirdLife International (2021) Important Bird Areas factsheet: Kozushima island. Downloaded from on 20/01/2021.