Red List Category
for more information about the Red List categories and criteria
Justification of Red List category
This species is listed as Vulnerable owing to a rapid population reduction in the last three generations (44 years). Trends in the main population appear to have stabilised and, unless declines recommence the species may warrant downlisting to Near Threatened in future.
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.
Land-mass type - shelf island - Continental islands include all other islands or island groups. Generally they were once part of continents and lie on a continental shelf of < 200 m sea depth.
Realm - Nearctic - realm
Realm - Palearctic - realm
USFWS - Bird of Conservation Concern - Species listed by US Fish and Wildlife Service
IUCN Ecosystem -- Marine biome