Maui's dolphin - Ecology & Habitat

Slow breeding rate = high survival vulnerability

The subspecies is found in inshore waters, including river mouths, estuaries, harbours and shallow bays, commonly within about 5 nautical miles of the shore.

Social Structure
Mothers and calves often travel in small nursery groups for protection.
This dolphin tends to occur in groups of up to five individuals, which may aggregate temporarily. Young are reported to play with seaweed, blow bubbles and are involved with other 'games' which are considered to be important social behaviours. Hector's dolphin emits sounds that are thought to be used for communication, notably the complex clicks produced in large groups.

Life Cycle
Calves live on their mother's milk for up to a year, although they learn to eat fish and squid after about 6 months. Females mature sexually at 7-9 years old.

Breeding
Like other small dolphins, Maui's dolphins have a low reproductive rate - they breed just fast enough to replace the number of dolphins that die naturally. This slow birth rate means that Maui's dolphins are struggling to recover from human induced deaths.

Maui's dolphins do not pair for life but mate frequently. Females give birth to a single calf every 2 to 4 years, which is born with dorsal fins partly folded over and with fold marks along the bodies. The calf is large (50 - 60 cm) in proportion to its mother (only 1.2-1.4 m).

One female might have four calves in her 20 year life span.

Diet
Maui's dolphins spend most of their time making short dives (90 seconds or so) to find fish on the sea floor. They also feed on fish and squid in mid water and sometimes close to the surface.