Information-seeking in an echolocating dolphin

Dolphins gain information through echolocation, a publicly accessible sensory system in which dolphins produce clicks to investigate objects. We measured information-seeking behavior by counting clicks that a blindfolded dolphin directed toward the sample object in a three-alternative matching task with object sets that varied in discriminability: Indiscriminable (performance accuracy M = 33%) vs. Easy (performance accuracy M>90%). The dolphin produced a similar number of clicks when first investigating each set type. Across multiple sessions, however, the dolphin emitted fewer clicks only when investigating indiscriminable (vs. easy) sets. Reduced echoic investigation with indiscriminable, but not easy, object sets was not due to overall motivation: the differential relationship between click number and object set discriminability was maintained when difficult and easy trials were interleaved and when objects from originally difficult sets were grouped with more discriminable objects. Further analyses of...