Data Zone
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 ('triggering') IBA criteria.
Populations meeting IBA criteria ('trigger species') at the site:| Species | Red List | Season (year/s of estimate) | Size | IBA criteria |
|---|---|---|---|---|
| Black-tailed Gull Larus crassirostris | LC | resident (2003) | present | A4i |
| A4iii Species group - seabirds | n/a | breeding (2003) | min 10,000 pairs | A4iii |
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 assessment | |||
|---|---|---|---|
| Year of assessment | State | Pressure | Response |
| 2015 | very poor | high | low |
| Whole site assessed? | State assessed by | Accuracy of information | |
| yes | habitat | - | |
| State (condition of the trigger species' habitats) | |||
|---|---|---|---|
| Habitat | Quantity (% remaining) | Quality (% carrying capacity) | Result |
| Marine Coastal/Supratidal | good (>90%) | very poor (<40%) | very poor |
| Pressure (threats to the trigger species and/or their habitats) | ||||
|---|---|---|---|---|
| Threat | Timing | Scope | Severity | Result |
| Natural system modifications | happening now | most of population/area (50–90%) | moderate decline (10–30% over 3 generations) | high |
| Climate change and severe weather | happening now | most of population/area (50–90%) | slow decline (1–10% over 3 generations) | high |
| Pollution | happening now | most of population/area (50–90%) | slow decline (1–10% over 3 generations) | high |
| Invasive and other problematic species and genes | happening now | some of population/area (10–49%) | rapid decline (>30% over 3 generations) | high |
| Human intrusions and disturbance | happening now | some of population/area (10–49%) | slow decline (1–10% over 3 generations) | medium |
| Energy production and mining | likely in short term (<4 years) | some of population/area (10–49%) | moderate decline (10–30% over 3 generations) | medium |
| Geological events | likely in long term (>4 years) | some of population/area (10–49%) | slow decline (1–10% over 3 generations) | medium |
| Response (conservation actions taken for the trigger species and/or their habitats) | |||
|---|---|---|---|
| Designation | Planning | Action | Result |
| Whole area (>90%) covered by appropriate conservation designation | No management plan exists, but the management planning process has begun | Very little or no conservation action taking place | low |
| Year | Protected Area | Designation (management category) | % coverage of IBA |
|---|---|---|---|
| 1963 | Chokai | 国定公園 (V) | 100 |
| 1972 | Tobishima | 都道府県指定鳥獣保護区 (IV) | 93 |
| 2003 | Common fishery right area(Yamagata) | 共同漁業権区域 (VI) | 7 |
| Habitat | % of IBA | Habitat detail |
|---|---|---|
| Marine Coastal/Supratidal | - |
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Tobishima and Oshakujima islands (Japan). Downloaded from
https://datazone.birdlife.org/site/factsheet/tobishima-and-oshakujima-islands-iba-japan on 27/12/2024.