(Stephen Frink / Corbis)
Dolphin Tricks for Treats
Scientists observe bottlenose dolphins in Australia using shells as tools to catch food
Scientists still want to find out exactly how dolphins are trapping fish in the shells. (Murdoch University; Perth, Australia)
These bottlenose dolphins live in Shark Bay, off the western coast of Australia. (Jim McMahon)
When you eat fish, you probably eat it off a plate, using a fork. Well, the dolphins in Shark Bay, Australia, eat their fish from conch shells!
Scientists have found some of these bottlenose dolphins using their large beaks to trap fish in shells underwater. Then, carrying the shells to the surface, they shake out the fish into their mouths and eat them. Apparently, using the conch shells allows the dolphins to catch more fish than they would be able to without such a tool. The technique has been called “conching.”
Researchers noticed dolphins engaging in the behavior a handful of times from 2007 to 2009. Then this dolphin trend seemed to pick up.
Simon Allen, a scientist with the Murdoch University Cetacean Research Unit, was surprised to see the conching technique spreading. “In the last four months alone, the research team have seen and photographed the behaviour no less than six times, possibly even seven,” he said in a press release. He thinks the dolphins may be learning conching from one another.
If the technique is spreading, it would be an important discovery. Scientists have never been able to observe a group of animals learning something from one another over such a short period of time.
Dolphins are known to be highly intelligent. The size of their brain is large in proportion to their body size. Compared with other animals, they have highly developed communication and social skills.
This species of dolphin uses other tools also. They will break off pieces of sponge that grow in the ocean, for example, and use them to cover their beaks. This allows them to forage for food on the ocean floor without hurting their noses.
HOW DO THEY DO IT?
Scientists are going to keep trying to catch the dolphins in the act of conching. They hope to see evidence of the dolphins teaching one another the technique. They also want to know how the dolphins get fish in the conch shell. Do they push the fish into the shell with their beaks? Or do they chase the fish into the shell before carrying it up to eat?
However they do it, Allen believes these dolphins to be particularly clever. “I wouldn't be too surprised to find such cunning and devilish ploys being adopted by Shark Bay’s bottlenose dolphins,” he said in a statement.