Abstract
Whistle characteristics were quantitatively compared between both geographically separated and neighboring populations of Atlantic spotted dolphins ( Stenella frontalis ), bottlenose dolphins ( Tursiops truncatus ), and pilot whales ( Globicephala spp .) in U.S. waters to evaluate if intraspecific acoustic differences exist between groups. We compared nine whistle characteristics between continental shelf and offshore Atlantic spotted dolphins in the western North Atlantic and between northern Gulf of Mexico and western North Atlantic bottlenose dolphins and pilot whales using discriminant analysis. Offshore Atlantic spotted dolphin whistles were significantly different (Hotelling's T 2 , P = 0.0003) from continental shelf whistles in high frequency, bandwidth, duration, number of steps, and number of inflection points. Atlantic bottlenose dolphin whistles were significantly different (Hotelling's T 2 , P