Short-finned pilot whales are the second largest delphinids found in Hawaiian waters. Photo-identification has cataloged at least 1,200 distinct individuals around Hawaii, with an estimated 19,000-20,000 throughout the island chain. Resighting data suggests there are several communities of long-term resident groups, and that these groups are socially isolated. Occasionally, open-ocean going populations venture close to the islands, but they have never been documented associating with resident groups. Pilot whales live in a matriarchal society in which females stay with their birth pod for life. A healthy female will average 4-5 calves in her lifetime, and females may nurse some offspring for up to 15 years! In the waters of Hawaii, this social species has been documented associating with other cetaceans, and they are frequently followed by oceanic whitetip sharks.