ROTATIONAL SWIMMING TENDENCIES IN THE DOLPHIN (TURSIOPS-TRUNCATUS)

Anecdotal evidence suggests that dolphins placed in a pool exhibit ste reotypic swimming in circles. The present study confirmed these observ ations in a sample of thirteen dolphins. The majority of dolphins (84. 6%) showed highly consistent directional swimming in counterclockwise circles. The latter directionality held throughout the circadian cycle and resisted environmental manipulations. Only social interaction was capable of altering the directionality of circumnavigation. The consi stency of unidirectional swimming is considered paradoxical in view of the existing evidence regarding the alternating of hemispheric activi ty in sleeping dolphins.