Aggressive Behaviors of Adult Male Atlantic Spotted Dolphins: Making Signals Count during Intraspecific and Interspecific Conflicts

Abstract

Some species exhibit behavioral plasticity by altering their aggressive behavior based on their opponent. Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus) are two sympatric species resident to the northern Bahamas. We examined whether groups of adult male spotted dolphins demonstrated behavioral plasticity during two different types of aggressive interactions. We described and compared the types of aggressive behaviors used during intraspecific aggression and interspecific aggression with bottlenose dolphins. Between the years 1991-2004, twenty-two aggressive encounters (11 intraspecific (spotted only), 11 interspecific (spotted vs. bottlenose)) were behaviorally analyzed. Twenty-three specific aggressive Behavioral Events, further grouped into three Behavioral Types, were examined throughout these encounters. Similarities and differences in the use of the Behavioral Types occurred during intra- and interspecific aggression. Groups of male Atlantic spotted dolphins altered their behavior during aggressive encounters with male bottlenose dolphins. Spotted dolphins increased their use of the Pursuit Behavioral Type and did not use the Display Behavioral Type significantly more than the Contact Behavioral Type during interspecific aggression. The increased use of a more overt and energy intensive Behavioral Type, Pursuit, suggests that Atlantic spotted dolphins altered their behavior during aggressive encounters with bottlenose dolphins to compensate during fights with a larger species and/or to effectively communicate with a different species.

Drones Assist in the First Report of a Mixed-Species Group of Tursiops truncatus (Common Bottlenose Dolphin) and a Stenella frontalis (Atlantic Spotted Dolphin) along the Southeast Florida Coast

“…The drone operator noted that play/mating behavior could be seen from the surface. Our analysis noted that the behavior observed resembled the side-mounting/copulation behavior that has been well documented in the Bahamas between male Common Bottlenose Dolphins and male Atlantic Spotted Dolphins (Cusick and Herzing 2014, Herzing 1996, Herzing and Elliser 2013, Volker and Herzing 2021). However, analysis of this interaction revealed only intraspecific side-mounting between Common Bottlenose Dolphins (Fig.…”

“…data). Reports of MSGs between Atlantic Spotted Dolphins and Common Bottlenose Dolphins exist throughout other portions of their range: the Azores (Clua and Grosvalet 2001), the Gulf of Mexico (Maze-Foley and Mullin 2006), oceanic waters off the coast of southeastern and southern Brazil (de Lima et al 2021), and many reports in the Bahamas (Cusick and Herzing 2014, Eireman et al 2019, Elliser and Herzing 2015, Herzing 1996, Herzing and Johnson 1997, Herzing et al 2003, Melillo et al 2009, Volker and Herzing 2021). Until now, to our knowledge, there have been no reported observations of these types of interactions along the southeast Florida coast in the literature.…”

“…In the Gulf of Mexico, aggressive behaviors such as jaw snaps and head-butting have been observed within MSGs of Atlantic Spotted Dolphins and Common Bottlenose Dolphins during 2 of 9 sightings (Maze-Foley and Mullin 2006). In the Bahamas, WDP has observed MSGs composed of Atlantic Spotted Dolphins and Common Bottlenose Dolphins engaged in social behavior, such as aggression, including behaviors such as side-mounting and copulation between males of both species (Cusick and Herzing 2014, Volker and Herzing 2021). This behavior is hypothesized to be a dominance display (Herzing and Elliser 2013, Herzing and Johnson 1997).…”

Integration of a social cluster of Atlantic spotted dolphins (Stenella frontalis) after a large immigration event in 2013

“…Additionally, satisfying the alternative definition, alliances have been observed in aggressive or competitive contexts with conspecifics as well as interspecies interactions with common bottlenose dolphins on GBB (D.L.H., unpublished data). Similarly, these types of interactions have also been documented on LBB (Cusick & Herzing, 2014;Volker & Herzing, 2021). Due to the lack of details on the CoA analyses for the Danaher-Garcia et al ( 2020) study, it is difficult to determine why the results were so different, however, it is clear that male alliances are present in the GBB community, at least since the immigration event occurred in 2013.…”

Diversity and Consequences of Social Network Structure in Toothed Whales

“…Instead, patterns of sexual segregation appear to be linked to species' mating systems. Among the species that sexually segregate, there is evidence that males engage in direct contests when competing for females (Kato, 1984;Dines et al, 2015;Allen et al, 2017;Volker and Herzing, 2021), and coercion of females by groups of males has been observed in some of these species, particularly spotted dolphins (Herzing, 1996) and Indo-Pacific bottlenose dolphins (Connor and Krützen, 2015). With the notable exception of sperm whales, males in these sexually segregated species tend to have more stable intrasexual social bonds than females.…”