Hydrochrous gigas (Hartert, EJO & Butler, AL, 1901) [orthographic error] The giant swiftlet (Hydrochous gigas), also known as the waterfall swift, is a species of bird in the swift family, Apodidae.

[2] It is found in Malaysia, Sumatra and Java, where its natural habitats are subtropical or tropical moist montane forests and rivers.

[3] It is a fairly large swift that can grow to 16 cm in length.

[4] Unlike other swiftlets, it builds its nest on a flat horizontal surface instead of molding it against a vertical surface with saliva.

[5] It is not totally nocturnal but able to orientate visually in dim light.