Red-bellied Pitta (Pitta erythrogaster) - HBW 8, p. 153

Taxonomy: Pitta erythrogaster Temminck, 1823, Manila, Luzon, Philippine Islands.
Closely related to P. kochi. Wide geographical variation in plumage, with some indication that coloration varies clinally, and also in voice. Distinctive race dohertyi sometimes treated as a separate species, mainly because it shows notable plumage differences and possibly differs vocally, but other intraspecific plumage variation is considerable, and claimed vocal differences remain uncertain; future research and DNA analysis may reveal that some other races, e.g. inspeculata, novaehibernicae, rubrinucha and splendida, should also be elevated to species rank; New Guinea taxa have sometimes been treated as separate species, P. macklotii. Other described forms include thompsoni (Calauit and Culion, in W Philippines), regarded as synonymous with highly variable nominate race; obiensis (Obi I, S of Halmahera), which is indistinguishable from rufiventris; and kuehni (Kai Is) and digglesi (N Queensland, Australia), appearing to show no constant differences from macklotii, although Australian birds considered by some authors to be brighter and paler. Race habenichti perhaps also better merged with last. Twenty-three subspecies recognized.