Māui dolphin

The Māui dolphin, also called Maui's dolphin or Popoto (Cephalorhynchus hectori maui), is a special type of dolphin found only in New Zealand. It is a subspecies of the Hector's dolphin and is one of the rarest and smallest dolphins in the world. These dolphins live only along the west coast of New Zealand's North Island.

There are very few Māui dolphins left. A report in 2021 estimated there were about 54 of them, but after recent losses, the number may be less than 40. Like the South Island Hector's dolphin, Māui dolphins face dangers from fishing activities, such as nets and traps, as well as diseases. Changes in climate and less food may also make it harder for them to survive.

Etymology

The name "Māui" in the dolphin's name comes from Te Ika-a-Māui, the Māori name for New Zealand's North Island. It refers to the Māori demigod Māui. In Māori, the word for a dolphin is popoto.

In English, the spelling isn't always the same. Originally, it was spelled "Maui's dolphin," but now people use several spellings like "Maui's dolphin," "Maui dolphin," "Māui's dolphin," and "Māui dolphin." This change shows a growing use of special marks in New Zealand English. The New Zealand Department of Conservation prefers the spelling "Māui dolphin."

Genetics

In 2002, Māui dolphins were named as a special group of Hector's dolphins. Scientists found that they look and act a little different from the dolphins in the South Island. These differences are very special because they live close together but still stay their own group.

Scientists think that the big water between the islands has kept the two groups apart for thousands of years. They are still learning more about whether these dolphins can mix together, but it might help them grow stronger. However, mixing too much could change what makes Māui dolphins special.

Physical description and life history

Māui dolphins look very similar to South Island Hector's dolphins. You can tell them apart from other dolphins in New Zealand by their grey, white, and black markings, short snouts, rounded dorsal fins, and small but strong bodies. Hector's dolphins are the smallest dolphin species in the world. Female Māui dolphins grow to about 1.7 meters long and can weigh up to 50 kilograms, while males are a bit smaller.

We believe Māui dolphins live about the same way as South Island Hector's dolphins. Hector's dolphins can live for at least 22 years and start having babies when they are about six to eight years old. They have a baby every two to four years. However, we still don’t know much about how Māui dolphins have babies and grow up.

Ecology and behaviour

Māui dolphins live in coastal waters where the water is murky. They spend a lot of time diving to the sea floor to find fish to eat, but they also look for food in the middle of the water and near the surface. Scientists don’t know a lot about what they eat, but they have found some types of fish in their stomachs.

These dolphins use a special skill called echolocation to find their way, talk to each other, and locate food. They make high-frequency clicks that bounce off objects in the water and return to them. This is different from other dolphins, who usually communicate with whistles.

Māui dolphins enjoy playing. They have been seen playing with seaweed, chasing each other, blowing bubbles, and having playful fights.

Population size, distribution and overlap with South Island Hector's dolphins

There are very few Māui dolphins left. In 2020–2021, scientists estimated there were about 54 of these dolphins. They live only along the west coast of New Zealand's North Island, usually in small groups close to the shore. These dolphins are considered critically endangered because there are so few of them left.

Sometimes, people see Māui or Hector's dolphins farther south, but these sightings are rare. Scientists have looked for them but haven't seen many in recent years.

Threats

Māui dolphins face several dangers that affect their small population. One major threat is getting caught in fishing nets, which can happen in both commercial and recreational fishing. To help protect them, rules have been put in place to limit where and how fishing can happen near their homes.

Another danger comes from diseases. Studies have shown that many Māui dolphins have been affected by a disease called toxoplasmosis, which can be spread by cats. This disease has been a cause of death for some dolphins. There is also a risk from another disease called brucellosis, which can affect pregnancy in dolphins.

Changes in the ocean due to climate change may also impact Māui dolphins, as they live in warmer waters where food might be harder to find. Scientists are working on new ways to track where these dolphins go using drones and computer programs to help protect them better.