Dolphins living in Shark Bay, Australia have developed a rare, and extraordinary new behaviour.
The dolphins have become shell-collectors, using their snouts to pick up and transport large conchs.
The dolphins seek out the shells to hunt fish that are sheltering within.
It is likely that the dolphins originally chased the fish into the conchs, and have now learnt to bring the shells to the surface, where they can flush out and eat their prey.

We were lucky enough to witness a dolphin being innovative
Marine biologist Simon Allen

Dolphin innovators collect shells
The foraging tactic is "quite spectacular", say researchers, who have published photographs and details of the behaviour in the journal Marine Mammal Science.
The dolphins of Shark Bay, Western Australia are well known to scientists, as they are one of the best studied dolphin populations in the world.
"Shark Bay dolphins are known as clever inventors, showing a remarkable range of foraging tactics, which are unprecedented in other cetacean populations," says biologist Dr Michael Krützen of the University of Zurich, Switzerland.
For example, these dolphins have developed a number of novel ways to catch fish.
Sometimes the dolphins 'hydroplane' into extreme shallow water, beating their tails furiously to pursue fish into the shallows where they are more easily caught.

A fish tail emerges from the conch
In doing so, the dolphins can beach themselves in pursuit of the fish, wriggling their way back into the sea.
They use another trick called 'kerplunking', whereby the dolphins slap their tails over beds of seagrass, creating bubbles that flush out fish hiding within.
Most remarkable, perhaps, is the technique known as 'sponging'.
Some dolphins intentionally pick up marine sponges with their snouts (known as a rostrum), and use them as 'gloves' or 'shields' to protect their sensitive snouts when rubbing them into the sandy seabed to forage.
This is a cultural trait passed down from mother to offspring, the only known example of culturally transmitted tool use among cetaceans.