The Dolphins of Laguna
A pod of resident bottlenose dolphins in the waters off Laguna, Brazil engages in behavior not seen anywhere else in the world: They aid local fishermen by trapping schools of fish (mullets) and herding them toward the beach, where the fishermen are waiting with nets.
When they get close to shore, the dolphins slap their tails or heads on the water, which tells the fishermen to cast their nets and indicates where they should cast them. The dolphins benefit as well because throwing the nets causes the fish to begin breaking away from their schools, making it easier for the dolphins to catch them. It should be noted that only some of the resident dolphins participate in the activity.
This collaboration has been going on since at least 1847, when Laguna became a city. The dolphins reportedly haven’t been trained in this behavior and presumably learn it from one another, passing it on from one generation to the next.
