Monotypic species endemic to Luzon in the Philippines.
Note that the form pinskeri, formerly considered conspecific, is now treated as a separate species
Visayan Hawk Eagle Nisaetus pinskeri.
Gamauf, A., J.O. Gjershaug, N. Rov, K. Kvaloy & E. Haring, (2005) Species or subspecies? The dilemma of taxonomic
ranking of some South-East Asian hawk-eagles (genus Spizaetus). – Bird Conservation International 15: 99-117.
Haring, E., K. Kvaløy, J.O. Gjershaug, N. Røv & A. Gamauf, (2007) Convergent evolution and paraphyly of the hawkeagles
of the genus Spizaetus (Aves, Accipitridae) - phylogenetic analyses based on mitochondrial markers. – Journal
of Zoological Systematics and Evolutionary Research 45: 353-365.