Long‐term interspecies association patterns of Atlantic bottlenose dolphins, Tursiops truncatus, and Atlantic spotted dolphins, Stenella frontalis, in the Bahamas

Abstract

With the exception of primates, detailed interspecies behavioral studies are rare in mammalian species and for cetaceans, most are anecdotal descriptions. This study is the first long‐term study on interspecies associations of regularly interacting groups. In the Bahamas Atlantic bottlenose (Tursiops truncatus) and spotted dolphins (Stenella frontalis) regularly form mixed species encounters (MSE). Both species show strong site fidelity with high resighting rates. During MSE, the majority (>65%) of spotted dolphins (especially males) were continually resighted; however bottlenose dolphins had comparatively low resighting rates (<17%). During MSE group size was significantly larger for spotted dolphins (13.0 ± 11.0) than bottlenose dolphins (4.8 ± 3.5) (F = 93.803, df = 1, P < 0.001). This difference was largest during aggressive encounters, due to the increased spotted dolphin group size (t‐test, t = 4.75, df = 184, P < 0.0001), but no difference in bottlenose dolphin group size. Strong associations (greater than twice the community average) were primarily between male spotted dolphins. Male alliances were prevalent for spotted dolphins but rare for bottlenose dolphins. These species differences were also observed in lagged association rates. These results highlight the differences involved in alliance formation and function for regularly interacting sympatric species and reveal insights into possible ecological and social reasons for these group formations.

Changes in interspecies association patterns of Atlantic bottlenose dolphins, Tursiops truncatus, and Atlantic spotted dolphins, Stenella frontalis, after demographic changes related to environmental disturbance

“…The bottlenose dolphin community size did not change due to an almost equal number of lost individuals (30) and immigrants (27) (Elliser and Herzing ). Only 14% of the bottlenose dolphin community were involved in MSE, which is consistent with prehurricane results (Elliser and Herzing ). Spotted dolphins had higher resightings (average number of times individuals were seen) than bottlenose dolphins, though not as drastic as prehurricane results.…”

“…Despite the reduction of community size by more than 30% for the spotted dolphins (Elliser and Herzing ), over 60% of the remaining spotted dolphin community was regularly involved in MSE, almost equal to the 65% in the prehurricane results (Elliser and Herzing ). The bottlenose dolphin community size did not change due to an almost equal number of lost individuals (30) and immigrants (27) (Elliser and Herzing ).…”

“…Permutation tests revealed nonrandom associations, indicating preferred and/or avoided companions (Table ). However, social differentiation was only close to intermediate differentiation at 0.437; and the correlation coefficient was moderate (CC = 0.50, Table ), indicating the CoA matrix was “somewhat” representative, indicating the data were less representative compared to prehurricane results with S > 0.60 and CC > 0.67 (Ellise r and Herzing ).…”

“…). Analyses of the interspecies associations (Elliser and Herzing ) and behavior (Herzing and Johnson , Cusick and Herzing ) of this study population of spotted and bottlenose dolphins reveal complex social interactions during mixed species encounters (MSE). Obvious species differences have been documented.…”

Exploration of Horizontal Information Transmission through Social Learning in Juvenile Atlantic Spotted Dolphins (Stenella frontalis)

“…The bottom is primarily sandy, with zones of rock, reef and patches of seagrass (Thalassia testudimum). The life history, including non-invasive genetic analysis, (Elliser & Herzing, 2012, 2013, 2016a, 2016bGreen, Herzing & Baldwin, 2007 and the development and use of social and acoustic behaviors of this community of Atlantic spotted dolphins have been documented extensively Herzing, 2000Herzing, , 2004Herzing, , 2005Herzing & Brunnick, 1997;Herzing & dos Santos, 2004;Herzing & Johnson, 1997;Herzing, Moewe & Brunnick, 2003;Lammers, Au & Herzing, 2003;Miles & Herzing, 2003;Welsh & Herzing, 2008).…”