Red List Category
for more information about the Red List categories and criteria
Justification of Red List category
This species is listed as Vulnerable because, although conservation efforts have resulted in a steady population increase, it still has a very small breeding range, limited to Torishima and Minami-kojima (Senkaku Islands), rendering it susceptible to stochastic events and human impacts.
1500-1700 mature individuals
Distribution size (breeding/resident):
Land-mass type - oceanic island - Oceanic islands are islands or island groups that are <200,000 sq km in size and separated from other land masses by >200 m sea depth. Generally Oceanic islands are islands or island groups that are <200,000 sq km in size and separated from other land masses by >200 m sea depth. Generally they have never been connected to a continental area by a land-ridge, and are volcanic in origin.
Realm - Indomalayan - realm
Realm - Nearctic - realm
Realm - Oceanic - realm
Realm - Palearctic - realm
IUCN Ecosystem -- Marine biome