Occurrence of bottlenose dolphins (Tursiops truncatus) in the Río Negro Estuary, Argentina, and their mid-distance movements along the northeastern Patagonian coast

Mauricio Failla, Verónica A. Seijas, Els Vermeulen

Abstract


A systematic study was carried out on bottlenose dolphins (Tursiops truncatus) in the Río Negro Estuary (RNE), Patagonia, Argentina, to analyze their occurrence and activity patterns in this region. The photo-identification data of this study was further compared to data from an adjacent region to gain information on the animals' movements along the northeastern Patagonian coast. Information was gathered through land-based observations between the
months of March and July of 2008 up to 2011. Data on dolphin activity patterns were collected via an ad libitum focal-group sampling mode. At the same time, dorsal fin images were obtained from as many dolphins as possible for
identification and subsequent re-identification of individuals. Total effort equaled 188h, resulting in 58h of observation of 124 dolphin groups [sightings per unit effort (SPUE) = 0.66 group/h]. Most of the groups observed contained between one and five individuals, and two main activity states could be determined, namely traveling (65%) and foraging (26%). The photo-identification effort, which started opportunistically in 2006, resulted in a catalogue of 17 individual dolphins, with a total mean re-identification rate of nine days (max. = 24 days). When comparing these pictures to the existing catalogue of Bahía San Antonio (BSA; approximately 200km west from the study area) dorsal fins of 15 individuals could be matched and most (n = 12) could be subsequently re-identified in both areas, indicating their long distance movements along the northeastern Patagonian coast during the austral autumn months. This season
coincides with the lowest dolphin abundance and feeding activity in BSA. This study indicates that bottlenose dolphins enter the RNE to forage at least during autumn. It further suggests that the search for food resources is the main trigger for their movement patterns along the northeastern Patagonian coast during this season, at least for certain individuals. More research is needed to accurately confirm these hypotheses.


Keywords


Photo-Identification; Behaviour

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References


Acevedo, A. (1991) Behaviour and movements of bottlenose dolphins, Tursiops truncatus, in the entrance to Ensenada de La Paz, Mexico. Aquatic Mammals 17(3): 137-147.

Altmann, J. (1974) Observational study of behaviour: Sampling methods. Behaviour 49: 227-265. http://dx.doi.org/10.1163/156853974X00534

Ballance, L.T. (1992) Habitat use patterns and ranges of the bottlenose dolphin in the Gulf of California, Mexico. Marine Mammal Science 8(3): 262-274. http://dx.doi.org/10.1111/j.1748-7692.1992.tb00408.x

Bastida, R. and Rodríguez, D. (2003) Mamíferos marinos de Patagonia y Antártica. Editorial Vázquez Manzini, Buenos Aires, Argentina.

Bearzi, M. (2005) Aspects of ecology and behaviour of bottlenose dolphins (Tursiops truncatus) in Santa Monica Bay, California. Journal of Cetacean Research and Management 7: 75-83.

Bearzi, G., Bonizzoni, S. and Gozalvo, J. (2011) Mid-distance movements of common bottlenose dolphins in the coastal waters of Greece. Journal of Ethology 29(2): 369-374. http://dx.doi.org/10.1007/s10164-010-0245-x

Berrow, S.D., Holmes, B. and Kiely, O. (1996) Distribution and abundance of bottle-nosed dolphins Tursiops truncatus (Montagu) in the Shannon estuary, Ireland. Biology and Environment: Proceedings of the Royal Irish Academy 96B(1): 1-9.

Coscarella, M.A. and Crespo, E.A. (2010) Feeding aggregation and aggressive interaction between bottlenose (Tursiops truncatus) and Commerson’s dolphins (Cephalorhynchus commersonii) in Patagonia, Argentina. Journal of Ethology 28(1): 183-187. http://dx.doi.org/10.1007/s10164-009-0171-y

Coscarella, M.A., Dans, S.L., Degrati, M., Garaffo, G.V. and Crespo, E.A. (2012) Bottlenose dolphins at the southern extreme of the south-western Atlantic: local population decline? Journal of the Marine Biological Association of the United Kingdom 7 pp.

http://dx.doi.org/10.1017/S0025315411001901

Defran, R.H. and Weller, D.W. (1999) Occurrence, distribution, and site fidelity of bottlenose dolphins (Tursiops truncatus) in San Diego, California. Marine Mammal Science 15:366–380.

http://dx.doi.org/10.1111/j.1748-7692.1999.tb00807.x

Defran, R.H., Weller, D.W., Kelly, D.L. and Espinosa, M.A. (1999) Range characteristics of the Pacific coast bottlenose dolphins (Tursiops truncatus) in the southern California bight. Marine Mammal Science 15:381–393. http://dx.doi.org/10.1111/j.1748-7692.1999.tb00808.x

Fisher, D.O. and Owens, I.P.F. (2000) Female home range size and the evolution of social organization in macropod marsupials. Journal of Animal Ecology 69: 1083–1098. http://dx.doi.org/10.1046/j.1365-2656.2000.00450.x

Gubbins, C. (2002) Use of home ranges by resident bottlenose dolphins (Tursiops truncatus) in a South Carolina estuary. Journal of Mammalogy 83(1): 178-187. http://dx.doi.org/10.1093/jmammal/83.1.178

Irvine, A.B., Scott, M.D., Wells, R.S. and Kaufmann, J.H. (1981) Movements and activities of the Atlantic bottlenose dolphin, Tursiops truncatus, near Sarasota, Florida. Fishery Bulletin 79: 671-688.

Laporta, P., Martins, C.C.A., Lodi, L., Domit, C., Vermeulen, E. and Di Tullio, J.C. (2016) Report of the Working Group on Habitat Use of Tursiops truncatus in the Southwest Atlantic Ocean. Latin American Journal of Aquatic Mammals 11(1-2): 47-61. http://dx.doi.org/10.5597/lajam00215

Leatherwood, S. and Reeves, R.R. (1990) The Bottlenose Dolphin. Academic Press, San Diego, CA, USA.

Lodi, L., Wedekin, L.L., Rossi-Santos, M.R. and Marcondes, M.C. (2008) Movements of the bottlenose dolphin (Tursiops truncatus) in the Rio de Janeiro state, southeastern Brazil. Biota Neotropica 8(4): 205-209.

http://dx.doi.org/10.1590/S1676-06032008000400020

Lusseau, D., Wilson, B., Hammond, P., Grellier, K., Durban, J.W., Parsons, K.M., Barton, T.R. and Thompson, P.M. (2005) Quantifying the influence of sociality on population structure in bottlenose dolphins. Journal of Animal Ecology1: 1-11.

Mann, J. (1999) Behavioural sampling methods for cetaceans: A

review and critique. Marine Mammal Science 15(1): 102-122. http://dx.doi.org/10.1111/j.1748-7692.1999.tb00784.x

Mate, B.R., Rossbach, K.A., Nieukirk, S.L., Wells, R.S., Irvine, A.B., Scott, M.D. and Read, A.J. (1995) Satellite monitored movements and dive behavior of a bottlenose dolphin (Tursiops truncatus) in Tampa Bay, Florida. Marine Mammal Science 11:452–463.

http://dx.doi.org/10.1111/j.1748-7692.1995.tb00669.x

Mattos, P.H., Rosa, L.D. and Fruet, P.F. (2007) Activity budgets and distribution of bottlenose dolphins (Tursiops truncatus) in the Patos Lagoon estuary, southern Brazil. Latin American Journal of Aquatic Mammals6(2): 161-169. http://dx.doi.org/10.5597/lajam00121

McLoughlin, P.D. and Ferguson, S.H. (2000) A hierarchical pattern of limiting factor helps explain variation in home range size. Ecoscience 7:123–130.

Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (2002) Encyclopaedia of marine mammals. Academic Press, San Diego, USA.

Reynolds, J.E., Wells, R.S. and Eide, S.D. (2000) The Bottlenose Dolphin: Biology and Conservation. University Press of Florida, Gainesville, USA.

Sandell, M. (1989) The mating tactics and spacing behaviour of solitary carnivores. Pages 164–182 in Gittleman, J.L. (Ed.) Carnivore behaviour, ecology and evolution. Cornell University Press, New York, USA.

Scott, M.D., Wells, R.S. and Irvine, A.B. (1990) A long-term study of bottlenose dolphins on the West coast of Florida. Pages 235-244 in Leatherwood, S. and Reeves, R.R (Eds) The Bottlenose Dolphin. Academic Press, San Diego, CA, USA.

Shane, S.H. (1990) Behaviour and ecology of the bottlenose dolphin at Sanibel Island, Florida. Pages 245-266 in Leatherwood, S. and Reeves, R.R. (Eds) The Bottlenose Dolphin. Academic Press, San Diego, CA, USA.

Silva, M.A., Prieto, R., Magalhães, S., Seabra, M.I., Santos, R.S. and Hammond, P.S. (2009) Ranging patterns of bottlenose dolphins living in oceanic waters: implications for population structure. Marine Biology 156: 179-192. http://dx.doi.org/10.1007/s00227-008-1075-z

Simões-Lopes, P.C. and Fabian, M.E. (1999) Residence patterns and site fidelity in bottlenose dolphins, Tursiops truncatus (Montagu) (Cetacea, Delphinidae) off southern Brazil. Revista Brasileira de Zoologia 16(4): 1017-1024. http://dx.doi.org/10.1590/S0101-81751999000400012

Vermeulen, E. (2011) Residency, abundance and social composition of bottlenose dolphins (Tursiops truncatus)in Bahía San Antonio, Patagonia, Argentina. Ph.D. Thesis. University of Liège. Belgium. 56 pp. http://hdl.handle.net/2268/119747.

Vermeulen, E. and Cammareri, A. (2009a) Residency patterns, abundance, and social composition of bottlenose dolphins (Tursiops truncatus) in Bahía San Antonio, Patagonia, Argentina. Aquatic Mammals 35(3): 379-386.

Vermeulen, E. and Cammareri, A. (2009b) Variation in external morphology of resident bottlenose dolphins in Bahía San Antonio, Patagonia, Argentina. Journal of Marine Animals and Their Ecology 2(2): 3-6.

Wells, R.S., Scott, M.D. and Irvine, A.B. (1987) The social structure of free-ranging bottlenose dolphins. Pages 247-305 in Genoways, H.H. (Ed.) Current mammalogy Vol. 1. Plenum Press, New York, USA.

Wells, R.S., Hansen, L.J., Baldridge, A., Dohl, T.P., Kelly, D.L. and Defran, R.H. (1990) Northward extension of the range of bottlenose dolphins along the California coast. Pages 421-431 in Leatherwood, S. and Reeves, R.R. (Eds) The Bottlenose Dolphin. Academic Press, San Diego, CA, USA.

Wells, R.S., Rhinehart, H.L., Cunningham, P., Whaley, J., Baran, M., Koberna, C. and Costa, D.P. (1999) Long distance offshore movements of bottlenose dolphins. Marine Mammal Science 15: 1098–1114.

http://dx.doi.org/10.1111/j.1748-7692.1999.tb00879.x

Wilson, B. (1995) The ecology of bottlenose dolphins in the Moray Firth, Scotland: A population at the northern extreme of the species’ range. Ph.D. Thesis. University of Aberdeen. Aberdeen, Scotland. 218 pp.

Wood, C.J. (1998) Movement of bottlenose dolphins around the southwest coast of Britain. Journal of Zoology 246: 155–163.

http://dx.doi.org/10.1111/j.1469-7998.1998.tb00144.x

Würsig, B. (1978) Occurrence and group organization of Atlantic bottlenose porpoises (Tursiops truncatus) in an Argentine bay. The Biological Bulletin 154: 348-359. http://dx.doi.org/10.2307/1541132

Würsig, B. and Würsig, M. (1979) Behaviour and ecology of bottlenose dolphin, Tursiops truncatus, in the South Atlantic. Fishery Bulletin 77: 399-442.

Zolman, E.S. (2002) Residence patterns of bottlenose dolphins (Tursiops truncatus) in the Stono River Estuary, Charleston County, South Carolina, U.S.A. Marine Mammal Science 18(4): 879-892.

http://dx.doi.org/10.1111/j.1748-7692.2002.tb01079.x




DOI: http://dx.doi.org/10.5597/00226

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