Systematics

There are three subspecies of Bare-faced Ibis. Differences are mainly in body size and in coloration of the bill and facial skin. Phimosus infuscatus berlepschi (Hellmayr 1903) exhibits deep carmine bare skin in the head, and a dark bill. This subspecies occurs in northern Colombia, eastern Ecuador, Venezuela, Guyana and Surinam and is smaller than P. infuscatus nudifrons (Spix 1825). The second subspecies, P. i. nudifrons, has paler coloration, is larger than the other two subspecies, and is found in central and eastern Brazil. The third subspecies, P. i. infuscatus (Lichtenstein 1823) is similar coloration to nudifrons but is smaller; this subspecies is found in Bolivia, Paraguay, Uruguay, and northern Agentina (Blake 1977).

he Bare-faced Ibis, together with other ibises and spoonbills, belongs to the order Pelecaniformes, which also includes herons and storks (Hackett et al. 2008).
P. phimosus is a member of the family Threskiornithidae, which includes nine species closely related to members of the heron family (Ardeidae). Threskiornithids have long and wide wings, are good flyers despite their body size and weight, and have long necks and beaks and elongated bodies. Within the family, the monotypic genus Phimosus is considered to belong to the ibis subfamily Threskiornithinae (Chesser et al. 2010), but the Bare-faced Ibis has not been included in molecular phylogenetic analyses of the family.