This taxon is Not Recognised as a species by BirdLife International.
Coryrthornis cristatus, C. nais and C. thomensis (del Hoyo and Collar 2014) were previously placed in the genus Alcedo and lumped as A. cristata following Melo and Fuchs (2008). Prior to that, all three taxa had been split as A. cristata, A. thomensis and A. nais following Sibley and Monroe (1990, 1993).
BirdLife International (2016) Species factsheet: Alcedo cristata. Downloaded from http://www.birdlife.org on 07/12/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 07/12/2016.