This taxon is Not Recognised as a species by BirdLife International.
Stiphrornis erythrothorax (Sibley and Monroe 1990, 1993) was previously split into S. erythrothorax, S. sanghensis, S. gabonensis and S. xanthogaster following Beresford and Cracraft (1999), but this treatment is no longer accepted following a review by the BirdLife Taxonomic Working Group. This is because the plumage differences are relatively slight and while DNA data suggests fairly substantial isolation of these taxa, the sampling was from one locality each, fairly distant from the next. Moreover, vocal analysis was inconclusive as to the degree of difference between sanghensis and other taxa. Finally, it is not clear whether there is intergradation or parapatry where the taxa meet; there is mention of apparent intergradation in Cameroon. Collar (2005) took the view that it is premature to regard these taxa as four different species, a view followed by the BirdLife Taxonomic Working Group, at least for the present.
BirdLife International (2016) Species factsheet: Stiphrornis xanthogaster. Downloaded from http://www.birdlife.org on 04/12/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/12/2016.