JP088
Kazan-retto islands


IBA Justification

The site was identified as internationally important for bird conservation in 2004 because it was regularly supporting significant populations of the species listed below, meeting IBA criteria.

Populations meeting IBA criteria ('key species') at the site:
Species Red List Season (year/s of estimate) Size IBA criteria
Red-tailed Tropicbird Phaethon rubricauda LC breeding (2003) present A4ii
Japanese Woodpigeon Columba janthina LC resident (2003) present A2
Matsudaira's Storm-petrel Hydrobates matsudairae VU breeding (2003) present A4ii

IBA Conservation

Ideally the conservation status of the IBA will have been checked regularly since the site was first identified in 2004. The most recent assessment (2015) is shown below.

IBA conservation status
Year of assessment State Pressure Response
2015 very unfavourable high low
Whole site assessed? State assessed by Accuracy of information
no habitat -

State (condition of the key species' habitats)
Habitat Quantity (% remaining) Quality (% carrying capacity) Result
Forest good (>90%) very poor (<40%) very unfavourable

Pressure (threats to the key species and/or their habitats)
Threat Timing Scope Severity Result
Geological events likely in short term (within 4 years) whole popul­ation/area (>90%) moderate deteri­oration (10–30% in 3 gener­ations) high
Invasive and other problematic species and genes likely in short term (within 4 years) most of popul­ation/area (50–90%) moderate deteri­oration (10–30% in 3 gener­ations) high
Biological resource use happen­ing now some of popul­ation/area (10–49%) slow deteri­oration (1–10% over 3 gener­ations) medium
Human intrusions and disturbance happen­ing now few individ­uals/small area (<10%) no deteri­oration (<1% over 3 gener­ations) low

Response (conservation actions taken for the key species and/or their habitats)
Designation Planning Action Result
Most of site (50–90%) covered (including the most critical parts for important bird species) No manage­ment planning has taken place Some limited conservation initiatives are in place low

IBA Protection

Year Protected Area Designation (management category) % coverage of IBA
1972 Ogasawara 国立公園 (II) 17
1975 Minami io jima 原生自然環境保全地域 (Ia) 11
2002 Common fishery right area(Tokyo) 共同漁業権区域 (VI) 3
2007 Ogasawara Islands 森林生態系保護地域 (Ib) 25
2009 Kitaiojima 国指定鳥獣保護区 (IV) 17
2011 Ogasawara Islands World Heritage Site (natural or mixed) (UA) 28

Habitats

Habitat % of IBA Habitat detail
Forest -
Grassland -
Marine Coastal/Supratidal -


Recommended citation
BirdLife International (2025) Important Bird Area factsheet: Kazan-retto islands (Japan). Downloaded from https://datazone.birdlife.org/site/factsheet/kazan-retto-islands-iba-japan on 13/01/2025.