False killer whales are large members of the dolphin family and a similarity to killer whales is the shape of their skull. The scientific name for false killer whales means “thick-tooth,” a nod to their pointed teeth and fierce, predatory behavior in the open seas.
Found in open waters throughout the tropics and sub-tropics, particularly surrounding the Hawaiian Islands, false killer whales are considered naturally rare, despite being high on the food chain. One of the most abundant populations of false killer whales can be found offshore from Hawaii and comprises roughly 1,550 individuals. Within these populations, false killer whales often break off into smaller, more stable groups of 15 to 25 individuals. Studies have shown that false killer whales form strong social bonds within the groups lasting several years. Together, false killer whales are cooperative hunters, foraging for squid and large fish, like tuna, mahi mahi and wahoo, and sharing the prey among each other.
False killer whales are identifiable by their rounded heads, small dorsal fin and dark gray bodies. They are most closely related to Risso’s dolphins and pilot whales, rather than killer whales as their name suggests. Playful and active, false killer whales are fast swimmers and can frequently be seen surfing the bow waves of vessels or poking out of the water. Like other dolphin species, they use echolocation to communicate and sense prey and their surroundings. False killer whales have a slow life history—females reach sexual maturity at about 10 years of age and may only have a calf every six or seven years. Calves are born just six feet in length, and will feed on the mother’s milk for up to two years.
Though false killer whales are listed as data deficient by the IUCN Red List, the main Hawaiian Islands population is listed as endangered under the U.S. Endangered Species Act. As overfishing of commercially important fish stocks continue, false killer whales will have less to eat. Additionally, bycatch likely occurs where these mammals overlap with fisheries.