This taxon is Not Recognised as a species by BirdLife International.
Egretta gularis (del Hoyo and Collar 2014) contains the taxon dimorpha, which was previously included within E. garzetta following Kushlan and Hancock (2005). Prior to that, all three taxa were treated as separate species following Sibley and Monroe (1990, 1993).
BirdLife International (2016) Species factsheet: Egretta garzetta. Downloaded from http://www.birdlife.org on 05/12/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 05/12/2016.