The Sunda owlet (Taenioptynx sylvaticus) is a small owl from Borneo and Sumatra.
This species was formerly treated as a subspecies of the collared owlet (Taenioptynx brodiei). It was promoted to a separate species based largely on the basis of a difference in vocalisation.
There are two subspecies:
T. s. sylvaticus (Bonaparte, 1850) - montane Sumatra T. s. borneensis (Sharpe, 1893) - montane Borneo
References
Further reading
Duncan, James R. (2003) Owls of the World: Their Lives, Behavior and Survival. Firefly Books