Millerbird Acrocephalus familiaris

Family: Acrocephalidae (Reed-warblers)

Authority: (Rothschild, 1892)

Red List Category

Criteria: B1ac(iv)

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Justification of Red List category
This species qualifies as Critically Endangered because it occurs on one extremely small island and undergoes marked population fluctuations, owing to climatic events, reducing it to tiny numbers. Such fluctuations have led to extensive and strikingly low levels of genetic diversity, making it extremely vulnerable to extinction through exposure to stochastic factors including the accidental introduction of mammalian predators, non-native pest plants or insect species, as well as severe climatic events and disease.

Population size: 250-999

Population trend: Stable

Extent of occurrence (breeding/resident): 2 km2

Country endemic: Yes

Land-mass type - oceanic island
Realm - Oceanic
IUCN Ecosystem -- Terrestrial biome

Recommended citation
BirdLife International (2022) Species factsheet: Acrocephalus familiaris. Downloaded from on 26/09/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 26/09/2022.