Red List Category
for more information about the Red List categories and criteria
Justification of Red List category
This species qualifies as Critically Endangered because the very rapid rate of decline in its very small global population observed over the past three generations is expected to increase owing to habitat loss and degradation combined with the impact of introduced predators including the possible arrival of Brown Tree Snake (Boiga irregularis
) on Saipan. This snake is a likely factor in the reed-warbler's extirpation from Guam.
2000-2499 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 - Oceanic - realm
IUCN Ecosystem -- Freshwater biome
IUCN Ecosystem -- Terrestrial biome