Taxonomy and Systematics
The taxonomy is complex with this and several other currently recognized species earlier treated as subspecies of Hypsipetes madagascariensis. Within Asia, H. ganeesa has often been listed as a subspecies of H. leucocephalus, but is increasingly treated as a separate species restricted to the Western Ghats (south of somewhere near Bombay ) and Sri Lanka, the Square-tailed Black Bulbul. The subspecies from Sri Lanka humii is then placed under this species.
The nominate race leucocephalus (J. F. Gmelin, 1789) is found north and east of the Himalayas in south eastern China, Myanmar and Indochina. The race psaroides Vigors, 1831 is found along the Himalayas from Afghanistan (Kunar Valley), through, Pakistan and India (Arunachal Pradesh) into northwestern Myanmar. Race sinensis (La Touche, 1922) is found in China, Thailand, Laos and Vietnam. Race nigrescens Stuart Baker, 1917 is described from Assam, Manipur, Myanmar (Chin Hills). Several other subspecies have been proposed including stresemanni, ambiens, concolor (may include impar), leucothorax, nigerrimus and perniger. Of all the races of this bulbul, stresemanni, leucothorax and leucocephalus have white heads, while all the others are black-headed. One of the white-headed races of this bulbul has been reported from Namdapha National Park in Arunachal Pradesh in Northeast India in 2009. The reproductive isolation mechanisms such as vocalization and geographic distributions of these populations still remain to be studied.
Read more about this topic: Black Bulbul