Dolphins help to catch fish

In the town of Laguna in southern Brazil, dolphins often help local fishermen. A group of dolphins drives a school of fish to the shore, at this time the fishermen stand in shallow water. Then one of the dolphins turns over at the right moment, which serves as a sign for the fishermen to throw the nets into the water. The advantage of dolphins is that they feast on fish that have escaped the nets and swim towards them. No one specifically trained dolphins for this behavior, and the first mention of cooperation dates back to 1847.