Endangered Hector's Dolphins
The Hector’s dolphin is among the world’s smallest marine dolphins. They are found only in the inshore waters of Aotearoa/New Zealand and are now very rare and at risk of extinction.
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 Maui’s dolphin which is found off the west coast of the North Island.
What do they look like?
There are many Kaikoura dolphins to spot on our tours, but Hector’s dolphins are the only dolphins in New Zealand with a wellrounded black dorsal fin that looks a little like a MIckey Mouse ear.
Their bodies are a distinctive grey, with white and black markings and a short snout.
Adult South Island Hector’s dolphin don’t often exceed 1.5 metres 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 Kaikoura 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.
- 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.
Threats to Hector’s dolphin
Kaikoura dolphins and people have shared our shores 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 Maui and Hector’s dolphins. 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 Kaikoura 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.
Other potential threats to their survival include trawling, marine pollution, disease and impacts of tourism and aquaculture.
You can help Hector’s dolphins
If you find stranded Kaikoura dolphins:
Ring Department of Conservation immediately on:
0800 DOCHOTline (0800 362 468)
- Avoid using set nets, particularly when you cannot remain with your net. If you see dolphins in the area, please remove your nets from the water.
- Please don’t swim with Kaikoura dolphins except with authorised tourist operators. If swimming near dolphins, avoid wearing suntan lotion or insect repellent as chemicals can irritate dolphin’s eyes.
- Do not try to touch a Hector’s dolphin.
- If in a boat use a “no wake” speed within 300 metres of dolphins. Should you need to outdistance them, you may increase your speed gradually to a maximum of 10 knots.
- Do not feed Kaikoura dolphins. Human food is harmful.
- Keep their environment clean. Take your rubbish home, and if you find any floating at sea or on the coast, please pick it up.
- Co-operate with others so all may see dolphins without putting them at risk.
Hector’s dolphin killed in a set net
- Contact the Ministry of Fisheries on 0800 4 POACHER (0800 4 76224) if you see set nets being used within closed areas.
- If you accidentally catch or harm a dolphin you must report it as soon as possible to DOC or Mfish.
- Keep the animal wet, but don’t pour water down its blow hole
- Keep the animal upright
- Keep the animal shaded from the sun
To report whale or dolphin sightings or strandings phone the DOC HOTline 24 hour emergency number:
0800 DOC HOTline (0800 362 468)