No subspecies of False Killer Whale (Pseudorca crassidens) are currently recognized. However, there is evidence of geographic variability in skull morphology and life history (Kitchener et al. 1990, Ferreira et al. 2014). Based on genetics there is substantial population structure, both between and within-ocean basins, and even within a single archipelago (Martien et al. 2014). This species has been intensively studied only in Hawaii (Baird 2016) and more recently in New Zealand (Zaeschmar 2014). In Hawaii, three subpopulations have been identified based on a combination of genetic studies (Martien et al. 2014), satellite tagging (Baird et al. 2010, 2012, 2014, Bradford et al. 2014a), and analyses of photo-identification data (Baird et al. 2008, Baird 2016). These include two partially overlapping insular populations, one around the main Hawaiian Islands, and one in the northwestern Hawaiian Islands, as well as a partially overlapping pelagic population that ranges throughout and beyond the U.S. Exclusive Economic Zone (EEZ) around the Hawaiian Archipelago. In New Zealand, based on high resighting rates of photo-identified individuals and a relatively small number of individuals documented, it is likely that this represents a distinct subpopulation (Zaeschmar 2014). While the number of subpopulations world-wide is unknown, this is due primarily to incomplete sampling in most of the range. Based on the evidence from Hawaii, subpopulation structure likely exists throughout their range.