London, (PA) - Dolphins have been seen for the first time using tools to find food and defend themselves, researchers believe.
US scientists studying bottle-nosed dolphins in Shark Bay, Western Australia, observed five females carrying sponges on the tips of their snouts as they searched for food on the seabed. They appeared to use them as protection against the spines and stings of animals like stonefish and stingrays -- and also to rake up prey.
The discovery was made by Dr Rachel Smolker from Michigan University in Ann Arbor, one of the world's leading DOLPHIN experts. Her observations, published in the journal Ethology and reported in New Scientist magazine today, are thought to be the first evidence of practical use of tools by dolphins in the wild.
Mark Simmonds, marine scientist at the Whale and Dolphin Conservation Society in Bath, said: "Rachel Smolker is one of the great DOLPHIN researchers. I think her discovery is extremely interesting".
"Dolphins are a very different kind of animal to ourselves and the primates in that they don't have hands, but that doesn't mean they can't manipulate objects."
He said young dolphins had frequently been seen playing with bits of floating seaweed, plastic or netting. In captivity, dolphins could be taught to balance objects on their noses, push buttons and pull levers.
"We have been running a study around Cornwall and Devon over the last four years and have seen them pulling anchor chains," said Simmonds.
"Obviously they can manipulate things. It's not surprising at all to hear that they use tools. The important point is that a group of dolphins were seen, obviously it's not play behaviour, and it seems to be serving some useful purpose."
He said dolphins had been filmed playfully manipulating air bubbles in the same way as a smoker blows smoke rings. They would lie on the seabed, blow a ring-shaped bubble, and then blow a second bubble through the middle of the first.
The problem with studying DOLPHIN behaviour was that they were usually only observed on or near the surface of the sea, said Simmonds. He added: "We can't see what they are doing a lot of the time. For all we know they might be down there stacking shelves and playing chess."