Ecology
Bottlenose dolphins exchange special whistles with each other when they meet on the high seas, researchers said. It is believed that these marine mammals may be able to talk just like humans.
Earlier studies have shown that the distinctive whistle is unique to each dolphin. With the help of such a whistle, mammals are able to exchange information and communicate with each other. Translated into human language, a dolphin's “speech” could mean “Hi, I'm George, I'm a big 3-year-old dolphin, I'm in great health, I'm not going to hurt you.”
The most recent research, published in the journal Proceedings of the Royal Society B, has shown for the first time how free dolphins can use whistles to communicate. The results of these studies once again prove that dolphins have unique and very complex communication systems in the animal world, which are perhaps superior even to humans.
“In my opinion, the term language describes human communication systems that are unique to us,” says Vincent Janik from St. Andrew. — It is reasonable to ask whether there are communication systems that are similar in complexity to our system. I think dolphins' communication systems are just as complex as those of other animals.”
Yanik and his colleagues studied bottlenose dolphins in St. Andrew, on the coast of northeastern Scotland. They watched dolphins communicate with each other and recorded their “conversations”.
An analysis of observations and records showed that dolphins usually swim in groups, move slowly and quietly.
“If another group approaches them, one or more animals start to make a characteristic whistle,” says Janick. “Then we heard that dolphins from another group start making sounds to them in answer, then the animals unite into one common group and continue to swim together. Shortly after teaming up, the dolphins stop and swim in silence again.”
Most animals have their own communication systems that allow them to meet and communicate, but dolphins have a very unique communication system: they can invent and copy new sounds. This is not like the communication system of lower primates, which have a specific set of sounds they use.
Scientists also noticed that usually only one dolphin from each group emits a distinctive whistle before group members come together. Perhaps this means that dolphins choose their “delegate” who represents the whole group during the meeting. This “delegate” may be older, but scientists believe that other dolphins are not completely silent, but may use echolocation instead of whistling.
“We don't know if echolocation works in this case, but it seems plausible,” the scientists said. “In this case, the whistle exchange is more than just a welcome ceremony. By using these sounds, dolphins express friendly intentions and may help to get to know the band after the first performance.”
Dolphins at a distance may rely more on sounds and echolocation to communicate than on sight, smells, and other cues. Perhaps this is due to the aquatic environment and social structure. A dolphin can hear another dolphin whistling more than 10 kilometers away and at an increased noise level.