Report of the Working Group on the Behavioral Ecology of bottlenose dolphins in the Southwest Atlantic Ocean

Abstract

In this report, we present a compilation of the behavioral patterns of bottlenose dolphins and social structure throughout the Southwest Atlantic Ocean. We have compiled and summarized available data concerning: (i) behavioral activities (states and events), (ii) social structures (group size and composition), (iii) acoustic behavior and (iv) intra and interspecific interactions of bottlenose dolphin populations throughout the SWAO, from northern Brazil to southern Argentina. Lack of systematic and standardized methodologies for data collection precludes robust data analyses in respect of bottlenose dolphin behavior. Available information suggests that the studied populations presented weak intra-population associations and that coastal individuals tend to form smaller groups than their oceanic counterparts. Bottlenose dolphins from SWAO produce stylized whistles in which the acoustic parameters are similar to published ranges around the world and some results indicate significant local inter-population variation in the acoustic parameters of the whistles. Data of intra and interspecific interactions of bottlenose dolphins in the SWAO are scarce and therefore do not fully allow a comprehensive analysis of the situational contexts.

Tursiops truncatus ssp. gephyreus: Vermeulen, E., Fruet, P., Costa, A., Coscarella, M. & Laporta, P.

“…Daura-Jorge et al 2012, Vermeulen 2018. The mean group size ranges from three to six individuals, depending on the locality (see Domit et al 2016 for review), with a maximum group size of around 50 animals recorded in Bahía San Antonio, Argentina ). Lahille's Bottlenose Dolphin consumes a wide variety of fish and cephalopod species.…”

Initial results on the variation of whistle characteristics of bottlenose dolphins from two neighbouring regions of the Mediterranean Sea: Northern Ionian and Southern Adriatic Sea

“…As sound propagates further than light or chemicals in the marine environment, many marine animals have evolved to be sensitive to sound. Thus, the cumulative increase in anthropogenic sound may elicit many short and long-term effects, from behavioural and habitat alterations to area avoidance, to changes in population dynamics and even physical injuries and mortality (La Manna et al, 2013;Domit et al, 2016;Bas ̧et al, 2017b;Fruet et al, 2017;Caruso et al, 2020).…”