Hector's dolphin

How it lives

Hector's dolphins live about 20 years, and photo-ID studies have followed individuals past 22. Males mature at about 6 to 9 years and females first calve at about 7 to 9. Females have 4 to 7 calves in a lifetime, one every 2 to 3 years, mostly in spring and summer. Newborns are 60 to 80 cm long and weigh 8 to 10 kg. About 36 percent die in their first six months.

Where it goes

Hector's dolphin lives only in New Zealand coastal water, mainly around the South Island, and generally stays in shallow water close to shore. The Māui subspecies lives only off the west coast of the North Island, between Maunganui Bluff and Whanganui, usually in water under 20 m deep. The sources I opened do not give home-range distances.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

The South Island population was estimated at 14,849 dolphins in 2017 (95 percent range 11,923 to 18,492). The Department of Conservation gives roughly 15,000 dolphins older than one year. The Māui subspecies off the North Island is Critically Endangered. The latest estimate, from 2020 to 2021, is 54 animals aged one year or older (95 percent range 48 to 66), and the true number may now be under 40. Banks Peninsula Marine Mammal Sanctuary was expanded in 2020 to about 14,310 sq km, with gillnet limits out to 4 nautical miles. The species is Endangered on the IUCN Red List and on CITES Appendix II.