Family Swifts (Apodidae)

Least Concern

Asian Palm-swift (Cypsiurus balasiensis)


French: Martinet batassia German: Bengalensegler Spanish: Vencejo palmero asiático

Cypselus Balasiensis

J. E. Gray

, 1829,



Species name often erroneously listed as batasiensis. Considered closely related to C. parvus, with which previously considered conspecific. Race infumatus distinctive#R, being considerably darker than nominate and with blue-glossed blackish wings and tail, tail-streamers broader and shorter, tail fork less deep, juvenile with far less distinct pale edgings on wing and tail; taxonomic status may repay investigation. Four subspecies recognized.

Subspecies and Distribution
  • C. b. balasiensis (J. E. Gray, 1829) – most of Indian Subcontinent S of Himalayas, from NE India (S Gujarat and Delhi area) E to area W of Assam hills, Bangladesh and S to Sri Lanka.
  • C. b. infumatus (P. L. Sclater, 1866) – NE India (Assam hills) E to Hainan, and S through SE Asia to Malay Peninsula, Sumatra and Borneo.
  • C. b. bartelsorum Brooke, 1972 – Java and Bali.
  • C. b. pallidior (McGregor, 1905) – Philippines.
  • Sulawesi recently colonized (from S), subspecies not yet determined.

    Descriptive notes

    11–13 cm; 8·3–10 g. Very small swift with long thin wings and long, deeply forked tail shorter than that of adult C. parvus and lacking streamer-... read more


    Most common call is a pleasant twittering, typically several fast notes interspersed by a longer... read more


    Primary dependence on fan palms (Livistona, Borassus, Corypha, Areca... read more

    Food and feeding

    Hemiptera, Coleoptera and Hymenoptera recorded. Detailed Malaysian study of nestling diet (both faeces and bolus) found Coleoptera,... read more


    Virtually year-round with local variation of peak, mainly Mar–Aug in lowlands and Apr–Jun in hills, India; Dec to early Jul,... read more



    Status and conservation

    Not globally threatened (Least Concern). Common to locally abundant. Least common where fan palms at lowest density. May be absent where palm crowns vigorously cut back,... read more

    Recommended citation

    Chantler, P. & Boesman, P. (2020). Asian Palm-swift (Cypsiurus balasiensis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 23 February 2020).