This taxon is Not Recognised as a species by BirdLife International.
Tockus erythrorhynchus and T. damarensis (del Hoyo and Collar 2014) were previously lumped as T. erythrorhynchus following Sibley and Monroe (1990, 1993).
BirdLife International (2016) Species factsheet: Tockus erythrorhynchus. 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.