Rough-toothed dolphins are commonly observed around all of the main Hawaiian islands. The Hawaiian stock is estimated at slightly over 6000 individuals. Two smaller stocks have been described in Hawaiian waters, with a population of rough-toothed dolphins that inhabit waters surrounding Kauai and Ni’ihau and another small population of approximately 200 individuals inhabiting the Big Island.
These dolphins tend to be located around slope drop-offs where they likely hunt fish and cephalopods. These dolphins are usually found in close-knit pods of 10-20 individuals in which they share prey that is likely caught through cooperative hunting. The rough-toothed dolphin is named for ridges on their teeth and is a slender dolphin with a sloping head shape that can be diagnostic of the species.