Mandurah dolphin doing an 'occy toss' in estuary | VIDEO

Dolphin doing an 'occy toss' in Mandurah's estuary | VIDEO

The Hammond family captured this amazing footage last week of a dolphin 'playing' with it's food.

This unusual behaviour raises the question of why dolphins do this.

Is it hunting? Playing? Protecting it's young?

According Natalie Goddard of Estuary Guardians Mandurah, it's a feeding technique.

"That is what we call an 'occy toss'. It's one of the most spectacular feeding events observed in Mandurah's waters," she said.

Dolphins eat octopus but can't simply catch and swallow them whole like they would with a fish, as octopus tentacles are dangerous and could result in death.

"Octopus tentacles are very dangerous to predators as they are covered in suckers which could choke them.

"So to ensure it is safe to swallow, the dolphin tosses the octopus around multiple times to break it apart, wear out its reflex responses and disable, dismember and tenderize its tentacles.

"The octopus will often try and defend themselves with their suckered tentacles by latching onto the dolphin's smooth skin on their back, where they can't grab them, which is pretty funny to witness," Natalie said.

See more:

The Murdoch University Cetacean Research Unit have conducted extensive research of octopus handling behaviour in bottle-nose dolphins off the coast of Bunbury over a seven-year period.

A paper published in Marine Mammal Science, 'Complex prey handling of octopus by dolphins', (Sprogis et al. 2017) described how dolphins use two different methods.

The first is the 'shake', which involves them arching and rotating their body out of the water, while holding the octopus in their jaws and forcefully hitting it onto the water's surface.

The second is the 'toss' where they also raise their head and/or body out of the water and flick the octopus up, but they open their mouths so the octopus is tossed into the air, often sending it flying for several metres.

The dolphin retrieves the octopus and continues to shake and toss it at the surface, normally about 10-15 times.

The paper found octopus handling behaviour is more common in winter and spring and more prevalent among adult females.

It was also discovered that its normally done by dolphins who had a close association with other dolphins that handled octopus, leading researchers to believe it's a learned behaviour rather than something instinctual.

So in answer to the question of whether dolphins are hunting or playing, it's likely a little from column A and a little from column B.

It's mostly about feeding, but as Ms Goddard said, "It's like a special treat...and yes, they do play with it somewhat".

Read more: