Sunda Bush Warbler and Aberrant Bush Warbler often are treated as separate species, although the circumscription differs among authors (particularly with regard to subspecies intricatus and oblitus). Results from phylogenetic analyses (Olsson et al. 2006, Alström et al. 2011) based on a small number of loci are conflicting, both between studies and between different analyses of the same data. Awaiting further analyses, of genomic data and vocalisations, Sunda Bush Warbler is lumped into Aberrant Bush Warbler; nonetheless we continue to recognize a polytypic group Aberrant Bush Warbler (Sunda) Horornis flavolivaceus [vulcanius Group], with subspecies sepiarius, flaviventris, vulcanius, kolichisi, everetti, banksi, oreophilus, and palawanus.