Voice
Song is a melodious ringing mournful series of irregular notes, first rising then descending in pitch, 'phwee-wit, pwee-pee-pee-pee-peerrt', but variable.
Brown-cheeked Bulbul (Alophoixus bres) [XC182629]
by David Edwards from , Indonesia (call)
Brown-cheeked Bulbul (Alophoixus bres) [XC40452]
by Mike Nelson from , Indonesia (call)
Subspecies
Proposed subspecies bartelsi (from Java) is a synonym of nominate. Putative subspecies balicus (eastern Java, Bali) said to have browner ear-coverts than western Javan birds, but this feature also present on many specimens from latter region and therefore better considered a synonym of nominate.
The following 5 subspecies are recognised:
tephrogenys (Jardine & Selby, 1833) - Southern Myanmar (Tenasserim south of c. 14° north), southern Thailand, Peninsular Malaysia (not Singapore) and eastern Sumatra. Considered by some authors to be a distinct species, Grey-cheeked Bulbul (Alophoixus tephrogenys).
bres (Lesson, 1832) - Java and Bali.
gutturalis (Bonaparte, 1850) - Borneo.
frater (Sharpe, 1877) - Western Philippines (Calamians, Palawan, Balabac). Considered by some authors to be a distinct species, Palawan Bulbul (Alophoixus frater).
balicus Stresemann, 1913 - Eastern Java and Bali.
Similar Species
Ochraceous Bulbul (Alophoixus ochraceus) which has a more prominent crest and darker underparts.
References
See References.