Subspecies
Spizaetus cirrhatus (Sibley and Monroe 1990, 1993) has been split into Crested Hawk-Eagle (Nisaetus cirrhatus) and Flores Hawk-Eagle (Nisaetus floris) following Gjershaug et al. (2004).
Spizaetus nanus, Spizaetus lanceolatus, Spizaetus philippensis, Spizaetus pinskeri, Spizaetus nipalensis, Spizaetus alboniger and Spizaetus bartelsi (Sibley and Monroe 1990, 1993) and Spizaetus cirrhatus and Spizaetus floris (Gjershaug et al. 2004) have been transferred into the genus Nisaetus following Haring et al. (2006). Spizaetus africanus and Hieraaetus fasciatus (Sibley and Monroe 1990, 1993) have both been transferred into Aquila, also following Haring et al. (2006); and Hieraaetus kienerii (Sibley and Monroe 1990, 1993) has been transferred into the resurrected genus Lophotriorchis.
Subspecies limnaeetus (incorporating andamanensis and vanheurni) and floris sometimes considered two separate species on grounds of plumage and lack of crest, but behaviour appears to be identical.
The following 6 subspecies are recognised:
cirrhatus (Gmelin, 1788) - India south of Rajasthan and Gangetic Plain.
ceylanensis (Gmelin, JF, 1788) - Sri Lanka.
andamanensis (Tytler, 1865) - Andaman Is.
limnaeetus (Horsfield, 1821) - Northern India and Nepal through Burma, western and southern Indochina and Malay Peninsula to Greater Sundas and western and south-eastern Philippines (Palawan, Mindoro, Mindanao).
vanheurni (Junge, 1936) - Simeulue I (off western Sumatra).
BirdLife International Species Factsheet