Māui and Hector's are the only dolphins with a well-rounded black dorsal fin
Hector's dolphin and calf
Hector’s dolphins are among the world’s smallest marine dolphins, growing to around 1.5m in length. They are found only in the inshore waters of Aotearoa/New Zealand.
Two sub-species of Hector’s dolphins exist: the South Island Hector’s dolphin which is found around the South Island of New Zealand, and the Māui dolphin which is found off the west coast of the North Island.
Hector’s and Māui dolphin are known to Māori by other names, including tutumairekurai, aihe, papakanua, upokohue, tukuperu, tūpoupou, pahu, pōpoto and hopuhopu.
What do they look like?
They are the only dolphins in New Zealand with a rounded black dorsal fin. Their bodies are a distinctive grey, with white and black markings and a short snout.
Adult South Island Hector’s dolphins don’t often exceed 1.5 m in length and weigh between 40 and 60 kg. Males are slightly smaller and lighter than females.
Where are they found?
Hector’s dolphins are found around the coast of the South Island but distribution is patchy.
Populations are concentrated between Haast and Farewell Spit in the west, around Banks Peninsula in the east, and Te Waewae Bay and Porpoise Bay/Te Whanaga Aihe in the south.
Hector’s dolphins are known to live to a maximum of about 20 years.
Like other dolphins, Hector’s use echolocation to find their food. They send out high frequency ‘clicks’ that bounce off surrounding objects and fish, giving the dolphins a detailed picture of their surroundings. This sonar is not used all the time, which may be one of the reasons why the dolphins get caught in nets.
Females reach sexual maturity between seven to nine years of age. They produce just one calf every two to three years, making population increase a very slow process.
Hector's dolphins are one of the smallest marine dolphins in the world
Most females only have four or five calves in a lifetime. Calving usually occurs between November and mid-February, and calves stay with their mothers for up to two years.
Traditionally, Māori watched dolphin movements to predict the weather.
Dolphins and people have shared our coastal waters and bays for centuries. In recent years, there has been a worldwide increase in awareness of marine mammals and a greater desire to protect them.
Set net fishing poses a major threat to Hector’s and Māui dolphin. Like all marine mammals they need to come to the surface regularly to breathe. If they become tangled in set nets, they will hold their breath until they suffocate.
Because these dolphins occur close inshore, often in bays and harbours, they are at risk of being injured by boats. Newborn dolphins are particularly vulnerable as they swim relatively slowly, close to the surface. Some have been killed by boat propellers when unwary boaties have run them over.
A hector's calf killed by a boat propeller
The Banks Peninsula marine mammal sanctuary in Canterbury was established in 1988 primarily to reduce set-net deaths of Hector’s dolphins in the area.
The Marine Mammals Protection Regulations were introduced in 1992 to control marine mammal tourism activities.
Set-net controls were introduced to Canterbury in 2002 and in west coast North Island in 2003.
DOC, in a joint initiative with the Ministry of Fisheries developed a Draft Threat Management Plan released in 2007.
Since then additional fisheries restrictions have been implemented along with four new marine mammal sanctuaries and alterations to the Banks Peninsula marine mammal sanctuary.
Research and scientific studies continue to increase our knowledge about each sub-species’ ecology, conservation status, life history, and threats.
Improved management practices are continually being sought for these dolphins in an attempt to ensure their survival into the future.
Results of 2015 seasonal aerial surveys undertaken to update Hector’s dolphin abundance and distribution estimates along the west coast of the South Island. Together with similar surveys and analyses of the east coast in 2013 and south coast in 2010, the estimated South Island population of Hector’s dolphin is now 14,849 (CV: 11% 95% CI 11 923-18 492), double the previous estimate from surveys conducted in the late 1990s – early 2000s.
Find out more about our work with hector's dophins:
Hector's dolphins are only found in New Zealand’s waters
You can help
How to approach dolphins
From a boat:
- carefully approach dolphins from their side and slightly to the rear.
- operate your boat slowly and quietly at ‘no wake’ speed within 300 m.
- don't approach a group of dolphins if three or more boats are already within 300 m of the group.
- manoeuvre your boat carefully. Do not obstruct their path, cut through a group, or separate mothers from calves.
From a boat or swimming:
- avoid loud or sudden noises that could startle dolphins.
- don't swim with dolphins when calves are present.
- don't try to touch the dolphins or feed them.
- co-operate with others so all may see the dolphins without putting them at risk.
Stranded, injured, entangled, or deceased dolphins
Call DOC's emergency hotline immediately 0800 DOC HOT (0800 362 468) and follow any instructions from DOC staff. Prompt reporting increases the likelihood that we can save dolphins in distress and learn more about deceased dolphins, including conducting necropsies in some situations to identify the cause of death and to collect important scientific data that may help us manage threats to dolphins.
If you catch or harm a dolphin
It is not illegal to accidentally catch a dolphin, but you must report it.
If you accidentally catch, harm or kill a dolphin you must report it as soon as possible to our emergency hotline 0800 DOCHOT (0800 362 468) or the Ministry for Primary Industries (0800 008 333).
If a dolphin is alive you should release it back into the water as quickly and gently as possible, provided it is safe to do so.
If the dolphin is dead, take photos, and either release the carcass at sea or preferably bring it to shore for us to recover, particularly if you have caught a Hector's or Māui dolphin.
If you are set netting always remain with your net. Remove your net from the water if dolphins are seen in the area.
If you see set nets being used within areas closed for netting, contact the Ministry for Primary Industries on 0800 4 POACHER (0800 4 76224).
If you are in the North Island and think you’ve seen a Māui or Hector’s dolphin, report it straight away to our emergency hotline 0800 DOC HOT (0800 362 468). We are interested in all sightings of Māui or Hector's dolphins around the North Island, but especially south of Raglan and around the south and east coasts of the North Island.
If you have spotted a Māui or Hector’s dolphin in Taranaki, Wellington, Wairarapa, Hawke's Bay, Bay of Plenty, east coast Auckland, or Northland, our staff might contact you via phone or radio, and may attempt to collect a genetic sample on arrival. If you are unable to call, you can report the sighting online.
We need beachgoers and boaties to report sightings so we can better understand where these dolphins live. This will provide evidence to make the best decisions for Māui and Hector’s dolphin conservation.
If you need help identifying species, download the marine mammal sighting form (PDF, 416K) or (Word, 4,300K). You can use the images and descriptions to find out which species of dolphin you observed.
Record the details
Include as much information as possible with your sighting:
- the date, time and location (GPS coordinates if possible)
- the number of dolphins and estimated sizes
- the direction they were travelling
- take photographs or video if possible.
Hector's dolphins caught in a recreational set net