Karen Pryor Commissioner, Marine Mammal Commission, Washington, D. C.
Most of the large mammals that are trained to perform useful work for man, whether horse or dog, camel or yak, were brought into captivity and successfully domesticated by the dawn of recorded history. The dolphin, therefore, is a very recent addition to the roster of man's animal partners. We may think of dolphins primarily as performers, like circus animals, However, beginning in the early 1960s, dolphins have also become established as at least semi-domesticated animals, capable of performing useful tasks in their natural environment, the ocean. For example, at the United States Naval Ocean Systems Centers in San Diego and in Hawaii, dolphins have been trained to carry burdens and (as have sea lions) to seek, locate, and aid in the recovery of underwater objects.
Dolphins differ, however, from horses, dogs, and most other domestic animals, not only in being aquatic but in the methods by which they are trained. The training of behavior in terrestrial domestic animals is almost always accomplished by means of negative reinforcement, coercion, and restraint; and it is enforced with punishment. The ox moves forward to avoid the goad, and thus pulls the wagon. The dog must obey the leash, the horse the bridle. The sheep which will not move with the other sheep will be barked at or even bitten by the dog, and the dog which does not chase sheep when told to will be beaten by the shepherd. The dolphin, however, is not easily trained by these negative methods. You cannot use a leash or a bridle or even your fist on an animal which just swims away. The dolphin thus has become one of the few large mammals with