Species: Tursiops aduncus
Bundjalung name: Wajung
Status (IUCN Red List): Near threatened

Characteristics

• Length/size: Indo-Pacific bottlenose dolphins grow to 2.6m and weigh 230kg when mature. At birth, calves are around 1m in length and weigh between 9 and 21kg.

• Colour: Distinguished by their large curved dorsal fin, grey dorsal colouration and white ventral surface colouration. Adults have dark grey speckling on the underside that increases with age.

• Breeding/reproduction: Female bottlenose dolphins give birth after a gestation period of around 12 months. A bottlenose dolphin calf will remain dependent on its mother for 2-4 years. Female bottlenose dolphins reach sexual maturity between 8 to 10 years and males between 10 to 12 years of age. Bottlenose dolphins can live for over 50 years.

• Diet: Dolphins are carnivorous and feed on a variety of fish, squid, octopus and occasionally even crayfish.

Habitat: Indo-Pacific bottlenose dolphins are a coastal species that inhabit coastal areas, estuaries and bays through the temperate, subtropical and tropical regions of Australia and the greater Indo-Pacific region. 

Societies: Indo-Pacific bottlenose dolphins are typically found in groups of 5-15 individuals. Occasional aggregations of over 100 can be encountered. Bottlenose dolphins are very social animals and live in complex societies that can often be sexually segregated. Mature males often form a strongly bonded alliance with at least 3-4 other males. Females live in large groups and maintain a large network of associates within their home range. Many communities of bottlenose dolphins will remain in small home ranges along the coastal zone and have year-round residence. Bottlenose dolphins can be very active at the surface and can be seen leaping, surfing and tail-slapping.

Communication: Bottlenose dolphins produce a diverse range of sounds that include echolocation or sonar clicks, whistles, and burst pulse sounds such as ‘squawks’ and ‘squeaks’. Whistles are used to maintain contact, identify, and to locate other dolphins. Clicks are used for echolocation, assisting in navigation and feeding.

Threats: Indo-Pacific bottlenose dolphins are protected in Australian waters, however, their future remains uncertain. In Australia, pollution from marine debris, litter, run-off, noise, habitat degradation, interactions with fisheries, overfishing, climate change, coastal development and vessel activities threaten the survival of Indo-Pacific bottlenose dolphins.

Learn more with the Indo-Pacific bottlenose dolphin fact sheet.