Researchers observe risky 'strand feeding' behaviour in Australian dolphins

SYDNEY - Researchers revealed on Monday they have for the first time identified an exceptional hunting behaviour known as strand feeding in Australian dolphins, where the marine mammals deliberately beach themselves in order to catch their prey.

The method has been identified in just a handful of other dolphin groups internationally, and while effective, risks are the creatures becoming permanently stranded and unable to return to the water.

Southern Cross University researcher Dr Daniele Cagnazzi has been studying a pod of humpback dolphins in Queensland State's Fitzroy River for 13 years and used drone-mounted cameras to capture the unique behaviour.

"Once the prey has been localised a dolphin swims at high speed toward the shore, catches the fish in its mouth and remains stranded for a short time before sliding gently back into the water," Cagnazzi explained.

He said that while this type of feeding is very risky, it is also routinely repeated and must therefore provide an important proportion of the dolphins' feeding needs -- which can be as high as 6 percent of their own bodyweight in fish every day.

Cagnazzi said that the strand feeding he witnessed was by members of a large family group of around 100 humpback dolphins, who are long-term residents of the Fitzroy River.

Of that group, only about 15-20 of them engaged in strand feeding, most of which were females and juveniles, leading Cagnazzi to believe that the behaviour is taught from mothers to calves.