Red List Category
for more information about the Red List categories and criteria
Justification of Red List category
This species has been listed as Endangered because it has an extremely small occupied breeding range, and there is now evidence that that chick predation by introduced mice is causing very low breeding success and is likely to be causing the population to decline. It has not been recorded from Tristan de Cunha for 35 years, and, were it to be confirmed as extinct there, it may qualify for uplisting to Critically Endangered.
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 - Afrotropical - realm
Realm - Neotropical - realm
IUCN Ecosystem -- Terrestrial biome
IUCN Ecosystem -- Marine biome