Range resolution by an echolocating bottlenosed dolphin (Tursiops truncatus)

Utilizing a two alternative, forced‐choice (simultaneous stimuli presentation) procedure, the ability of a bottlenosed dolphin (Tursiops truncatus) to discriminate differences in target range by echolocation was determined. Target‐range difference discrimination trials were conducted at three different absolute ranges (1, 3, and 7 m). The range resolution acuity of the dolphin varied with absolute range. His 0.79 hit rate probability for the absolute range of one m was 0.9‐cm range difference; for the absolute range of 3 m it was 1.5 cm and for an absolute range of 7 m it was 2.8 cm. Behavioral data suggest that these levels of perceptual acuity are not usually attained and/or maintained during the dolphin's normal nonstatic prey pursuit. [Work supported by NUC.]