The Dolphins

The Mandurah Dolphins

The Mandurah Dolphins

The Mandurah Dolphins

The Mandurah Dolphins

Mandurah’s Dolphins

Mandurah’s Peel-Harvey estuary has a population of 80 resident dolphins, another ~ 40 that visit occasionally from coastal waters and hundreds more along our coast. Mandurah waterways are ideal for dolphins due to the abundance of fish which is their choice of food and the shallow, warmer, calm, protected waters which is great for birthing. The large population of dolphins in the region is a great sign of how healthy our waterways are to be able to sustain them.

The dolphins that inhabit the Peel-Harvey and adjacent coastal waters are Indo-Pacific bottlenose dolphins.

The size of an adult dolphin in Mandurah ranges from 2.3 – 2.6 metres long and they weigh up to 220kg. At birth they are approximately 1 metre in length, weighing up to 20kg.

Bottlenose dolphins can live to over 40 years of age. In fact, we have a number of dolphins in Mandurah older than 25 years that are happy and healthy including Nikki, Bendy Wendy Fourteen, Bitts, Blake, Jack Daniels, Frankenstein, Twenty Two and Zero One.

Dolphins live together in groups. They can have as little as 2 dolphins in their group to over a thousand. Here in Mandurah we typically see group sizes of 2 to 15 and sometimes up to 30. Swimming in numbers offers social benefits and protection from predators such as sharks. Our dolphins live in a fission-fusion society, which basically means that individuals come and go, groups form and break apart on a daily basis, with no matriarch or ‘dominant female’ in the group. Few dolphin species actually live in a matriarchal society (orca, pilot whales), where related individuals will stay together as family groups known as a ‘pod’.

Females are usually seen together and have a network of female friends while males usually bond closely to one other male and form a long-term partnership known as an ‘alliance’, where they feed, pursue females and do everything together. Males may also venture alone for periods of time.

Females have a baby which is called a calf every 2 to 3 years in Mandurah. The calf will then stay by its mothers side for up to 3 years and suckle her milk for the first 18 months, just like human babies do. At about 6 years of age the males will venture off from their mother and form strong bonds with other males, where as the females will usually continue to associate with their mother and birth pod.

Bottlenose dolphins predominantly take part in mating when the water temperature is above 20/21 degrees and here in Mandurah that is the warmer months from November to June. 

With a 12 month pregnancy term most calves are born during the mating season also. In 2017 we had 5 new calves in our inland waterways – Splash, Sea, Speckle, Nikaila and Andrew, on top of 10 new calves in 2016.

Dolphins are very social animals that have a very playful and cheeky manner about them. The most obvious sign of socialising between dolphins is body contact. Examples of body contact include rubbing their bodies against each other, stroking each other with their tail flukes or fins and nudging each other. Other physical socialising can include tail slapping, leaping into the air, chasing each other or throwing around objects such as seaweed and octopus in a playful manner.

They’re also social with animals outside their species. Off Mandurah’s coast they have been observed playing with whales as the whales migrate down the west coast to the Southern Ocean.

They are very curious creatures and like to socialise with us humans too. Here in Mandurah they can often be seen surfing on the wake of boats, swimming around vessels and looking at people observing them.

Mandurah’s dolphins predominantly eat fish. The amount of food they eat depends on the season – During summer water conditions, when they are warm, they do not need to maintain a thick blubber layer so they usually consume between 6-8kg per day. Whereas in winter they do a lot of feeding to maintain a thick blubber layer for the colder, winter conditions, consuming between 10-14kg a day!

Here in Mandurah we have observed some extraordinary feeding techniques. Small fish, like garfish, are caught with rapid chases, sometimes the dolphin swimming belly-up (snacking) while the fish tries to escape at the surface. Salmon is usually pursued against rock walls, mullet chased in the shallows and often stunned with an impressive tail whack, while an octopus gets tossed in the air.

Mandurah is identified as a dolphin a stranding hotspot. The estuary is a very shallow system and the dolphins can get stuck in the shallows and end up stranded when they navigate into these shallow areas and get caught out by the tide. When a dolphin strands, if not attended to quickly, can be fatal. Luckily in Mandurah we have The Mandurah Dolphin Rescue Group who monitor our dolphin population and go to the aid of any dolphins in trouble.

If you see a dolphin, or any other wildlife in sick, injured or in distress, please call the WILDCARE helpline on 08 9474 9055.

All of our dolphins are identified by marks and notches on their dosil fin and/or body. Here are some of the regulars we see on our cruises:

Coming soon…

Our tour guides captured spectacular footage of our dolphins daily. Follow us on Facebook, Instagram and YouTube for all the latest action. Here are some recent videos:

Murray River Lunch Cruise Dolphins – 14/10/2017 – Part 2

Murray River Lunch Cruise Dolphins – 14/10/2017 – Part 1

Dolphin Island Adventure – 08/10/2017