Globally threatened Sunda Blue Flycatcher Cyornis caerulatus: synthesis of global records and recent records from Sumatra

The Sunda Blue Flycatcher (or Large-billed Blue Flycatcher) Cyornis caerulatus is endemic to Borneo and Sumatra and classified as globally Vulnerable (BirdLife International 2011). Its ecology remains poorly known, although it is characterised as an insectivorous lowland rainforest specialist occupying the mid-strata, usually recorded up to 500 m asl (BirdLife International 2001, Myers 2009). There are also suggestions that it is generally uncommon, rather patchily distributed, with a strong preference for primary forest habitat and highly sensitive to forest disturbance such as logging and fragmentation (Lambert 1992, BirdLife International 2001, Slik & van Balen 2005). Current records are heavily clustered in Borneo (particularly north Borneo), with only six published records from Sumatra, of which only two are post-1930 (BirdLife International 2001). Here we synthesise records of the Sumatran subspecies C. c. albiventer, including field reports from conservation/forestry organisations and birdwatchers, as well as records from museum collections. We also report on six recent records of this species from fieldwork in southern Sumatra.