Rück's Blue-flycatcher Cyornis ruckii

Family: Muscicapidae (Old World Flycatchers and Chats)

Authority: (Oustalet, 1881)

Red List Category

Criteria: D

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Justification of Red List category
This species has not been recorded since 1918, and no forest remains in the vicinity of its two known collecting localities, so it may have declined severely as a result of habitat destruction. However, it cannot be assumed to have gone Extinct, because lowland forest in Sumatra has been relatively poorly surveyed, and the specimens were collected in "exploited forest", hinting at a tolerance to some degree of habitat degradation. Any remaining population is likely to be tiny, and for these reasons it is treated as Critically Endangered.

Population size: 1-49 mature individuals

Population trend: unknown

Extent of occurrence (breeding/resident): 6,600 km2

Country endemic: yes

Land-mass type - shelf island
Realm - Indomalayan
IUCN Ecosystem -- Terrestrial biome

Recommended citation
BirdLife International (2024) Species factsheet: Cyornis ruckii. Downloaded from on 01/03/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from on 01/03/2024.