Population of bottlenose dolphins off the east coast of Australia was divided into two groups, depending on the method of obtaining food, and ten years later teamed up again when one of the ways — the "easy" hunt near the trawler — became available, the BBC reported, citing a study published in the journal Animal Behaviour.
Scientists from Australia and New Zealand since 1997, watched the dolphin population — Indian bottlenose dolphins inhabiting the Bay Moreton (Moreton Bay) off the east coast of Australia. The researchers studied the association between individuals of the two groups using the social networks, where the interaction is monitored "everyone with everyone"
As scientists have determined, dolphins within this area were divided into two groups, one of which provide food for the journey trawlers, shrimp production, the other — to avoid these routes. While dolphins from different clans are almost never interacted with each other, despite the coincidence of the range.
Scientists believe the reason for the split — a kind of "social segregation". Some of the animals chose the "convenient" way to provide food (on the route trawlers — in places where the waste from shrimp attract fish). The remaining individuals of the population "by tacit agreement" did not apply to this item, as a result, is nearby, they hardly interacted.
However, after a change in the local rules of extraction of marine resources in 1999 to visit the bay trawlers stopped.
Over the next ten years, according to scientists, the dolphins of the two groups have to communicate more and then form a single compact pack.
"After production ceased shrimp, dolphins completely rebuilt their social system," — said the head of research, an employee of the University of Queensland, Ina Ansmann (Ina Ansmann), quoted at the post.
Dolphins are among the most intellectually developed on the planet. The brain of an adult dolphin more human — it weighs about 1.7 kilograms (in humans — 1.4), while in the cortex dolphin twice convolutions. According to numerous observations and scientific experiments, dolphins can communicate using the "vocabulary", which includes up to 14,000 audio signalova also osobznayut themselves in the social structure — among relatives.
Indian bottlenose or bottlenose dolphins (Tursiops aduncus) inhabit the waters of the Red Sea, the Southern and Indian Oceans. Bottlenose dolphins — the most common form of dolphins in the world.