Trainers use reinforcers to tell the dolphins what to do. A reinforcer is anything that increases the frequency, intensity, or duration of a particular behavior. Dolphin reinforcers can be fish, toys, tactile stimulation (rubdowns/petting), swimming with a trainer, or even learning a new behavior. When reinforcement is used the right way, dolphins can be trained to do many things. Eventually the trainers attach a hand signal to the desired behavior.
How does an animal know it has behaved correctly? Trainers use what is called a bridging stimulus ("bridge" for short). A bridge is a signal (either a whistle or a verbal stimulus such as "Good!") that the trainer communicates at the precise moment an animal does something correct. Each of these bridging stimuli tells the dolphin that it is correct, the behavior is over, and the dolphin can now receive some kind of reinforcement from the trainer.
A dolphin calf starts to notice people at about three months of age. Before that, the calf only interacts with its mother. The first thing a trainer teaches a calf once it’s ready to interact is to take food from the trainer's hand.
To train more advanced behaviors, we use small steps. Here's how we might train a dolphin to do a high jump behavior:
First, we lower a target (a bright red ball) from the ceiling to the surface of the water and reinforce the dolphin for touching it. Then, we raise the target a few inches above the water and reinforce the dolphin for touching it again. We continue to raise and reinforce in small steps. After many trials, the dolphin learns to high jump—18 feet above the surface of the water—and hit the target on cue!

