Most scientists believe that dolphins are on a level with chimpanzees and dogs. Dolphins can learn to perform certain actions. They learn best when actions are broken into small steps and they are given food or other rewards. The fathers of the calves do not live with the pod. We do not know what the social structure is for many kinds of dolphins.
Echolocation is a way of using sound to find objects in the environment.
Bats use it in the air and dolphins use it in the water. The sound bounces off objects, creating an echo that returns to the dolphins. We think that dolphins hear the returning echoes by feeling the sound pulses against their jaws. Dolphins can also judge how far away the object is by the amount of time it takes for the echo to return. No, all dolphins are not endangered.