rendered permanently invalid (as junior homonyms usually are) if "the substitute name is not in use" – which has been the case after Amadon's 1963 revision. Hence, in this case the scientific name Buteo melanoleucus can apply to the black-chested eagle-buzzard, even though the black-and-white hawk-eagle was described under exactly that name earlier, while the senior homonym melanoleucus still applies to the latter species when placed in Spizaetus according to the usual ICZN rules. Consequently, the proper name to use for each bird has through a number of coincidences become the senior synonym of the other species. References Further reading Amorim, James Faraco & Piacentini, Vítor de Queiroz (2006): Novos registros de aves raras em Santa Catarina, Sul do Brasil, incluindo os primeiros registros documentados de algumas espécies para o Estado [New records of rare birds, and first reports of some species, in the state of Santa Catarina, southern Brazil]. Revista Brasileira de Ornitologia 14(2): 145–149 [Portuguese with English abstract]. PDF fulltext Electronic supplement black-and-white hawk-eagle Birds of Central America Birds of South America black-and-white hawk-eagle Taxa named by Louis Jean Pierre Vieillot Taxonomy articles created by Polbot