8 Rarely Seen Dolphin Species

While some dolphin species are quite common, many are rare to see in the wild.

Hectors dolphin, endangered dolphin, New Zealand
Gary Webber / Getty Images

While some dolphin species are quite common, like the aptly named common dolphin and the bottlenose dolphin, many types of dolphins around the world are quite rare to see, either because they live in unusual environments, have small population sizes, or both. Here are 8 uncommon yet fascinating types of dolphins.

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Hourglass Dolphin

An hourglass dolphin jumping above the ocean's surface.
This jumping hourglass dolphin is displaying the species' characteristic hourglass-like white design.

Ken Griffiths/ Getty Images

The small, mostly black hourglass dolphin is named after the resemblance the dolphin's white spots have to an hourglass. Hourglass dolphins live in the cold waters of Antarctica's Southern Ocean and adjacent subantarctic waters. This type of dolphin is often sighted in areas with turbulent waters and is a frequent bow-rider of ships heading to Antarctica. The hourglass dolphin is rare to see due to its affinity for Antarctica's cold water, but the limited information available on this dolphin species suggests populations are healthy.

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Irrawaddy Dolphin

Two irrawaddy dolphins swimming.
While these dolphins may look like beluga whales, they are actually rare Irrawaddy river dolphins.

Gerard Soury/ Getty Images

If the Irrawaddy dolphin looks familiar, it may be due to the dolphin's resemblance to the beluga whale, which is in the same family as the Irrawaddy dolphin. However, unlike its beluga whale relative, most populations of the Irrawaddy dolphin are found in freshwater environments in Myanmar, Cambodia, Indonesia, and Vietnam. In the Ayeyarwady River, where this dolphin gets its name, the Irrawaddy dolphin is known to collaborate with fishermen. Fishermen can summon the dolphins by tapping the sides of their boats. The dolphins then herd groups of fish toward shore where the fish are more easily netted. The dolphins are thought to benefit from the fish's confused reaction to the net, which may make feeding on the fish easier.

Dams, fishing with electricity, and fishing net are among the many threats the Irrawaddy dolphin faces, All freshwater populations of the Irrawaddy dolphin are considered endangered.

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Short-Finned Pilot Whale

A short-finned pilot whale swimming in the dark ocean.
The short-finned pilot whale is actually a large type of dolphin.

Cavan Images/ Getty Images

Short-finned pilot whales are nomadic animals found around the world in tropical, subtropical, and warm temperate waters. Despite their name and short, whale-like snouts and large size, these animals are actually dolphins. Both short-finned pilot whales and their relatives, the long-fin pilot whale, feed primarily on squid. Growing up to 20 feet long, pilot whales are the second largest species of dolphin behind the killer whales, which are also technically dolphins. Currently, short-finned pilot whale numbers are relatively low around the world as a result of disease, unusually warm waters, and mass stranding events, making sightings of this dolphin species rare today.

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South Asian River Dolphin

A South Asian river dolphin swimming in a river.
The South Asian river dolphin is known to come to the surface quite inconspicuously.

Abdul Rauf/ Getty Images

The South Asian river dolphin is another freshwater dolphin species found in rivers in Pakistan, India, Bangladesh, and Myanmar. This dolphin has tiny eyes and a long, slender snout making it look perhaps more like a swordfish than a dolphin. The South Asian river dolphin is quite discreet. The animal usually surfaces quickly and unobtrusively, adding to the dolphin's rareness. The South Asian river dolphin is considered endangered, with about 5% of the remaining populations killed as fishing bycatch every year. The South Asian river dolphin is also suffering from substantial losses in the freshwater habitat on which they depend.

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Hector's Dolphin

Hector's dolphins swimming underwater near the ocean's surface.
These Hector's dolphins are among the world's smallest and rarest dolphin species.

Richard Robinson/ Getty Images

Hector's dolphin is one of four dolphin species of blunt-headed dolphins. The dolphins' short snouts make them easy to confuse with porpoises. Hector's dolphins are found exclusively in the waters off of New Zealand, where they are the country's smallest and rarest dolphin. The Māui dolphin, a subspecies of the Hector's dolphin, is even smaller and rarer. 2016 estimates suggest just over 60 adults make up the remaining population of Māui dolphins and about 15,000 animals make up the Hector's dolphin population.

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Taiwanese Humpback Dolphin

This rare dolphin species' existence was only just confirmed by surveys in 2002. The Taiwanese humpback dolphin lives exclusively in the shallow coastal waters of Taiwan's west coast where it is a year-round resident. Long-term surveys have consistently found less than 100 individuals.

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Commerson's Dolphin

A black and white Commerson's dolphin swimming just above the ocean's surface with two additional dolphins visible just under the water.
While most Commerson's dolphins live near Argentina, this relatively rate dolphin species has also been spotted in the Indian Ocean and near the Falkland Islands.

Ashley Cooper/ Getty Images

Commerson's dolphin, like the Hector's and Māui dolphins, is another one of the four blunt-headed dolphin species. Commerson's dolphin shares the title with Hector's dolphin for the world's smallest dolphin. Of the four species of blunt-headed dolphins, the Commerson's dolphin has the strangest distribution. The greatest portion of the species is found within the inshore waters of Argentina and in the Strait of Magellan, but this type of dolphin is also found at the Falkland Islands and at the Indian Ocean's Kerguelen islands.

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Melon-Headed Whale

Melon-headed whales underwater.
While these animals are commonly referred to as melon-headed whales, they are actually a species of dolphin.

Gerard Soury/ Getty Images

The melon-headed whale, like the pilot whale and killer whale, is actually a species of dolphin. This type of dolphin mainly lives in deep tropical waters and warm, temperate waters in the West Indo-Pacific, but is occasionally seen near South Africa and southern Australia. Despite the melon-headed whale's large global distribution, sightings of type of dolphin are relatively rare.

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