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 |
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 |
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 |
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.