BEHAVIOR AND ECOLOGY OF THE BOTTLENOSE DOLPHIN, 

 TURSIOPS IRUNCATUS, IN THE SOUTH ATLANTIC 



Bernd Wursig and Melany Wursig' 



ABSTRACT 



Bottlenose dolphins observed nearshore in Golfo San Jose, Argentina, spent 92% of their time in water 

 less than 10 m deep. They moved into deeper water, up to 39 m depth, mainly during midday in 

 nonsummer for brief ( 16 mm ) penods. They moved more rapidly m deeper water, and may have been 

 feeding on schoolmg fish at that time. During summer they stayed in shallow water, 2-6 m deep. 



Dolphins moved parallel to shore and in consistent depth of water at almost all times. They changed 

 direction at predictable locations and patrolled certam nearshore waters for up to several hours. Their 

 movement was mfluenced by tide and by nearshore rocks. 



Slow movement and apparent restmg occurred mainly during the morning, while most aenal 

 behavior, apparent sexual and social behavior, and rapid-movement feeding occurred in the afternoon. 



The Atlantic bottlenose dolphin, Tursiops triin- 

 catus , is undoubtedly the best studied of any of the 

 toothed cetaceans. It was successfully kept in cap- 

 tivity over 60 yr ago (Townsend 1914). and has 

 since that time served as the "white rat" of cetol- 

 ogy, with a great deal known about its behavior in 

 captivity, but until relatively recently practically 

 nothing known about its behavior in the wild. 

 Long-term behavioral studies of stable bottlenose 

 dolphin colonies in captivity were mainly carried 

 out at Marine Studios/Marineland of Florida from 

 the mid-1930's to mid-1950's (McBride 1940; 

 McBride and Hebb 1948; McBride and Kritzler 

 1951; Essapian 1953, 1963; Tavolga and Essapian 

 1957; Tavolga 1966). These studies showed that 

 bottlenose dolphins have a complex social organi- 

 zation, often with a male-dominated social hierar- 

 chy. From some of these studies also developed the 

 idea that bottlenose dolphins, and other odonto- 

 cete species as well, use echolocation (McBride 

 1956). This concept was validated by numerous 

 workers in the 1950's and 1960's (Schevill and 

 Lawrence 1956; Kellogg 1961; Norris et al. 1961). 

 Other research on captive bottlenose dolphins in 

 general (including the species T. gilli and T. 

 adtincus, as well as T. truncatus) was reported by 

 Brown and Norris ( 1956), Caldwell et al. ( 1965), D. 

 K. Caldwell and M. C. Caldwell (1972). M. C. 

 Caldwell and D. K. Caldwell (1972), Tayler and 

 Saayman (1972), and Saayman et al. (1973). The 



'State University of New York al Stony Brook. Program for 

 Neurobiology and Behavior; present address: Center for Coastal 

 Marine Studies. University of California, Santa Cruz, CA 95064. 



first reports of behavior in the wild consisted 

 mainly of anecdotal information gathered oppor- 

 tunistically while capturing dolphins or pursuing 

 other activities (Gunter 1942; Brown and Norris 

 1956; Norris and Prescott 1961; Brown et al. 

 1966). This led to more detailed field studies, most 

 of which have been made within the past 10 yr, 

 and all of which relied heavily on shore-based or 

 small-boat operations close to shore (Saayman et 

 al. 1972; Tayler and Saayman 1972; Irvine and 

 Wells 1972; Saayman et al. 1973; Saayman and 

 Tayler 1973; Shane 1977; Wursig and Wursig 

 1977; Castello and Pinedo 1977; Wursig 1978; 

 Wells et al. in press; Irvine et al.^). At the same 

 time, and also close to shore, behavioral investiga- 

 tions of other odontocete genera have been carried 

 out. Thus, Norris and DohF studied the Hawaiian 

 spinner dolphin, Stenella longirostris, Saayman 

 and Tayler (in press) described Indian Ocean 

 humpback dolphin, Sousa sp., behavior and social 

 organization, and Wursig and Wiirsig^ performed 

 similar work on the South Atlantic dusky dolphin, 

 Lagenorhynch us obscurus. 



iUanuscnpt accepted December 197H, 

 FISHERY BULLETIN VOL 77. NO 2. 1979. 



^Irvine, A. B., M. D. Scott. R. S. Wells, J, H, Kaufmann.and W. 

 E. Evans. 1978. A study of the movements and activities of 

 the Atlantic bottlenosed dolphin, Tur^iiops truncatus. including 

 an evaluation of tagging techniques. Final report for U.S. 

 Marine Mammal Commission Contracts MM4AC004 and 

 MM.5AC0018. .53 p. 



'Norris. K. S., and T. P. Dohl. The behavior of the Hawaiian 

 spinner porpoise, Stenella longirostris (Schlegel, 1841). Unpubl. 

 manuscr .. 66 p. Center for Coastal Marine Studies. University of 

 California. Santa Cruz. 



■* Wursig, B. G. , and M. A. Wursig. The behavior and ecology 

 of the dusky dolphin, Lagenorhychus obscurus. Unpubl. man- 

 user.. 64 p. Center for Coastal Marine Studies, University of 

 California, Santa Cruz. 



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