This taxon is Not Recognised as a species by BirdLife International.
Apalis porphyrolaema and A. kaboboensis (Sibley and Monroe 1990, 1993), previously retained as separate species, are now lumped into A. porphyrolaema following Dowsett and Forbes-Watson (1993) and a review by the BirdLife Taxonomic Working Group, given that the sole certain distinction is A. kaboboensis' all-dark throat (no evidence of a different eye colour, as illustrated in Sinclair and Ryan ).
BirdLife International (2016) Species factsheet: Apalis kaboboensis. Downloaded from http://www.birdlife.org on 03/12/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/12/2016.