� WWF-Canon/Stephen DAWSON

Numbering around 110, the Maui's dolphin (Cephalorhynchus hectori maui) is the world's smallest and rarest marine dolphin. Maui's dolphins are generally found along the North West coast of the North Island of New Zealand, between New Plymouth and Dargaville.

There are 32 species of dolphin (Delphinidae). The Maui's dolphin belongs to the genus Cephalorhynchus. This genus comprises four species:

• Hector's dolphin (only found in New Zealand) - this includes the sub species Maui's dolphin
• Heaviside's dolphin (found in South Africa and Namibia)
• Chilean dolphin (only found in Chile)
• Commerson's dolphin (found in Argentina, Tierra del Fuego, the Falkland Islands and the Indian Ocean).

All Cephalorhynchus species are small dolphins which inhabit shallow coastal waters, where they are vulnerable to entanglement in set nets and to run-off pollution.

A very special and rare New Zealand dolphin
The Maui's dolphin used to be called the North Island Hector's dolphin. Recently, researchers found that the Maui's dolphin is actually distinct from other Hector's dolphins. It has a distinct genetic and skeletal structure, as well as a slightly different body form. These differences probably evolved over many thousands of years of geographical separation and mean that Maui's and other Hector's dolphins are unlikely to breed together. The Maui's dolphin is classified as 'critically endangered' on the IUCN Red List. WWF fears that it may become extinct within 25 years.

Population decline
A first survey of Maui's dolphins in 1985 estimated the total population at 134. A January 2004 survey delivered a population estimate of 111 with a 95% confidence interval of 48-252. This recent work does not necessarily indicate a population decline but rather confirms the small population size of around 110 dolphins. In addition, information suggests that the range of the population has been reduced dramatically over recent decades. For example, Maui's dolphins were seen regularly in the Taranaki area in the 1970s, today they are no longer present there. Population modelling further suggests that if current trends continue, the Maui's dolphin could decline by as much as 75% of the current population within 15-20 years. The scarcity of information available about the Maui's dolphin makes protecting it even harder.
 
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