Why are these dolphins wearing sponges on their noses?

Some dolphins in western Australia have developed an unusual technique to help them find fish on the seafloor.

Scientists have spotted them biting sponges and "wearing" them on their snouts - a bit like a clown's nose!

This allows the dolphins to protect their noses while stirring up sand on the rocky seabed, helping them to uncover fish hiding underneath.

Experts say this new discovery could help us better understand use of tools by animals, as well as their behaviour in the wild.

What did scientists discover about the dolphins?

The dolphins were spotted using their sponge skills in Shark Bay in western Australia

The new research published in the Royal Society Open Science journal featured an international team of scientists.

They spotted that some bottlenose dolphins in Shark Bay, in western Australia, pick up sponges from the seafloor and use them as tools to help them hunt fish.

Experts have called this behaviour "sponging" and say that its a bit like wearing a glove - helping dolphins protect their sensitive skin whilst digging through rough sand and sharp rocks on the ocean floor.

Researchers say that it's a difficult hunting method and they've only spotted a small number of dolphins using the technique.

Ellen Jacobs, from Denmark's Aarhus University, who was involved with the study, explained: "Sponging is a very unique foraging behaviour. It's only dolphins in Shark Bay, Western Australia, that have been observed doing it.

"It's only about 5% of the population do this technique. So it's maybe like 30 dolphins right now. So it's quite rare."

Scientists think the art of sponge hunting is taught and passed down by mother dolphins to their offspring.

Dolphin calves usually spend around 3 or 4 years with their mothers, observing and learning important life skills.

Ms Jacobs added that dolphins can spend a lot of their time sponging in the water.

She said: "Once they've scared up a fish they will drop the sponge off of the front of the face and they will go after the fish, grab it, pick up their sponge again, and keep going and they'll do it for hours at a time."