Dolphins, like humans, deliberately teach new behaviors to their peers.
There is resent paper published by the researchers who study Indo-Pacific bottlenose dolphins (tursiops aduncus) in shark bay. They studied a specific behavior called “shelling’’ that consist in chasing a fish in order to make it to hide inside a big snail shell and then lifting up the shell to the surface of the sea in order to make the fish fall in the dolphin mouth.
They found that dolphins not only learned the shelling behavior from their mother or other adult dolphins (Vertical social transmission) but also learned the behavior from peers (horizontal social transmission). They highlighted this as a similarity with great apes who also learn foraging behaviors by imitation their peers.
But there is something that (non-human) apes do not do. Apes do not deliberately teach their peers or their calfs new behaviors, they only perform their behaviors as habitual and their peers and their calf learn by imitation.
Dolphins, like humans, deliberately teach new behaviors to their peers and they also perform foraging sessions specifically to teach the behavior to peers.
One example is the “strand feeding” behavior performed by common bottlenose dolphins (tursiops truncatus). That behavior was developed independently in at least 2 separate location. Georgia and Virginia coast in Atlantic ocean and the delta of the Colorado river in the California Gulf in the Pacific ocean coast.
This behavior consist in one dolphins choosing a mild muddy area on the shore without rocks and then a group of dolphins herds a school of mullet to that shore and then they come together to the shore making a wave that take the school of fish and dolphins out of the water. then they drag through the mud taking the defenseless fish.
This is a complex behavior with many stages and labor division that dolphins practice a lot without fish to teaches it to new members of the group.
Sometimes dolphins perform strand feeding foraging sessions without fish schools specifically to teach the behavior to peer.
Other example is the “crater feeding” behavior. This foraging behavior consist in a bottlenose dolphin echolocating the sea floor in search of buried fish. when the dolphin find one he stunt it with a sound pulse and unearth it with his rostrum letting a crater like hole in the sand.
This behavior have been extensively researched and observers have found that dolphins behave differently when there are calves present. Mother dolphins took around 5 times longer to catch their prey than when no calf present. They also made more “body oriented behaviors” when calf were present. This body oriented movements are described as exaggerated movements in direction of the prey and are intended to teach the calf the proper way to perform the behavior. There was some events of juvenile dolphins teaching the behavior in this way to calfs.
Other example is the experience witnessed by a Florida photographer who captures dolphin seemingly playing with red drum. In the photos it is possible to observe a adult male that herds a red drums school and catches one and releases it. This male repeated the behavior some times in front of younger peers to teach them the proper way to perform the behavior.
This male dolphin also performed body oriented movements to teach the younger peers how to herd and catch the red drums.
Orcas (a dolphin specie) also teach behaviors to their young. There are a lot of reports of orcas hunting whales making the hunt session unnecessarily long deliberately in order to let the young to practice the behavior.
Here you can read about one example.
In this event a group of more than 50 orcas from various pods hunted a 4–6 meters beaked whale.
They could have take the whale in minutes. But this attack lasted much longer than normal because it was a training exercise for the many calves involved in the hunt.
Some of the calves were leaping over the beaked whale and trying to push it down, while the females pushed up from below.
