SEASONAL-CHANGES IN VOCALIZATIONS DURING BEHAVIOR OF THE ATLANTIC BOTTLE-NOSED-DOLPHIN

Four vocalizations (whistles, buzzes, quacks, and pops) were quantifie d during three behavioral categories (socializing, traveling, and feed ing) of the bootlenose dolphin in the Newport River Estuary, North Car olina. This study tested the hypothesis that specific vocalizations of dolphins in this area are associated with specific behavioral categor ies during the summer and fall. Approximately twice the total number o f vocalizations per unit time occurred during the fall as compared to the summer. Each type of vocalization had a distinctive and consistent acoustical structure. The relative frequency of the different vocaliz ation types was significantly dependent on the behavior of the dolphin s. Pops were consistently associated with feeding, quacks with sociali zing, and buzzes with traveling. Whistles, the most common vocalizatio n, were associated with traveling and feeding during the summer and so cializing in the fall. Dolphins spent more time involved in undirected activity (socialization) during the summer but spent more time travel ing in search of food and feeding during the fall in preparation for m igration out of the estuary and movement south.