Endangered
Hector's dolphin
Cephalorhynchus hectori
Hector's dolphin is the only cetacean endemic to New Zealand, and comprises two subspecies: C.
Appearance
The body shape is stocky, with a large fluke relative to their body size and no discernible beak. The most distinctive feature is the rounded dorsal fin, with a convex trailing edge and undercut rear margin. The overall coloration of Hector's dolphins is a mixture of grey, white, and black.
Hector's dolphin is the smallest dolphin species.
Mature adults have a total length of 1.2–1.6 m (3 ft 11 in – 5 ft 3 in) and weigh 40–60 kg (88–132 lb).
Range and habitat
The species' range includes murky coastal waters out to 100 m (330 ft) depth, though almost all sightings are in waters shallower than 50 m (160 ft). Hector's dolphin is the only cetacean endemic to New Zealand, and comprises two subspecies: C. H. Hectori, the more numerous subspecies, also referred to as South Island Hector's dolphin, and C. H. Maui, the critically endangered Māui dolphin that is found off the West Coast of New Zealand's North Island. Their lifespan is typically around 20 years, and the species favours shallow coastal waters around the South Island, where they live in small groups and use echolocation clicks to communicate.
The South Island Hector's dolphin is most abundant in discontinuous regions of high turbidity around the South Island. Smaller populations are scattered around the South Island, among them: Cook Strait, Kaikōura, Catlins (e.g., Porpoise Bay, Curio Bay), and Otago coasts (e.g.Karitane, Oamaru, Moeraki, Otago Harbour, and Blueskin Bay).
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet
Hector's dolphins are generalist feeders, with prey selection based on size (mostly under 10 cm in length) rather than species, although spiny species appear to be avoided.
In crisis
Threats to the species include bycatch in gillnets and trawls, disease, genetic issues, and additional anthropogenic hazards. An aerial survey of South Island Hector's dolphin abundance—that was commissioned by the Ministry for Primary Industries, carried out by the Cawthron Institute, and endorsed by the International Whaling Commission—estimated a total population size of 14,849 dolphins (95% confidence interval = 11,923–18,492). The latest population estimate of the Māui dolphin was published in 2023, and indicated just 48 individuals.
The high levels of sex segregation and fragmentation of different populations in Hector's dolphin have been discussed as contributing to the overall population decline, as it becomes more difficult for males to find a female and copulate. The Allee effect begins to occur when a low-density population has low reproductive rates leading to increased population decline.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Hector's dolphin is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Hector's dolphin, Wikidata item Q300961. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
