Asian palm swift (Yến cọ, Cypsiurus balasiensis) 

The Asian palm swift (Cypsiurus balasiensis) is a small swift of the Apodidae family.
It is a common resident breeder in tropical Asia from India to the Philippines.

As the name apodiforme—meaning "footless" in Greek—suggests, the legs of hummingbirds, swifts and treeswifts (or 'crested' swifts) are rather small and offer limited functional uses.
The family name, Apodidae, is derived from the Greek ἄπους (ápous), meaning "footless", a reference to the small, weak legs of these most aerial of birds.
The genus name Cypsiurus comes from the Greek words kupselos (swallow) and ouros (tailed).
balasiensis from “Balasian Swift”, the name given to the Asian Palm, probably after the town and district of Balasore in the Bengal region.