Synchrony during aggression in adult male Atlantic spotted dolphins (Stenella frontalis)

2017 ◽  
Vol 20 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Alyson J. Myers ◽  
Denise L. Herzing ◽  
David F. Bjorklund
2021 ◽  
Vol 8 (1) ◽  
pp. 35-51
Author(s):  
Cassandra L. Volker ◽  
Denise L. Herzing

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.


Author(s):  
Denise L. Herzing ◽  
Cindy R. Elliser

In the Bahamas, interspecific groups of Atlantic spotted dolphins, Stenella frontalis, and bottlenose dolphins, Tursiops truncatus, have been observed underwater since 1985 on Little Bahama Bank. Mixed-species groups engage in associative behaviors and aggression on a regular basis. Because of their complex cognitive behaviors and large brain encephalization, dolphins are likely capable of complex social interactions, even between species.Between 1993-2003, 177 Mixed-Species Encounters (MSE) were categorized by the age class of male spotted dolphins, the ratio of spotted dolphins to bottlenose dolphins, behavior as Associative (traveling, babysitting, play) or Aggressive (chases, mounting, head to heads) and by directionality of sexual behavior. The majority (68%) of MSE involved adult spotted dolphin. Associative behaviors were observed more than aggressive behaviors in groups where no adult male spotted dolphin, only male calves, or male juvenile spotted dolphins were present. Aggressive behaviors were observed more frequently than associative behaviors in adult male spotted dolphin groups. When groups were unbalanced in favor of one species or the other, differences in social interactions occurred. Male spotted dolphins were never observed attempting to mount male bottlenose dolphin although they chased them. Despite the larger ratio of male spotted dolphins to bottlenose dolphins during MSE, directionality of male-to-male sexual contact was primarily one-way. Male bottlenose dolphin mounted and copulated with male spotted dolphins but not the reverse. Opportunities for cross-species mating and hybridization clearly occurred. Male bottlenose dolphins copulated with female spotted dolphins and male spotted dolphins copulated with female bottlenose dolphins. These sympatric dolphins in the Bahamas have a complex and dynamic relationship that varies with sex and age and revolves around potential reproductive isolation issues.


Bioacoustics ◽  
2017 ◽  
Vol 27 (2) ◽  
pp. 145-164 ◽  
Author(s):  
J. Daisy Kaplan ◽  
Kelly Melillo-Sweeting ◽  
Diana Reiss

2011 ◽  
Vol 89 (3) ◽  
pp. 239-253 ◽  
Author(s):  
Michelle L. Green ◽  
Denise L. Herzing ◽  
John D. Baldwin

Cetaceans are known to frequently engage in sexual behavior; however, the lack of male parental investment in offspring makes assessment of male reproductive success difficult. We assessed paternity in a small population (mean individuals sighted per year = 93) of Atlantic spotted dolphins ( Stenella frontalis (G. Cuvier, 1829)) utilizing noninvasively collected fecal material. Samples (n = 88) were collected from dolphins from four social clusters. Of the 29 offspring tested, 34.5% were assigned paternity, resulting in 10 paternities assigned to seven males. Our study indicates that achieving a certain age is a potential precursor for males to mate successfully, as 18 years was the youngest estimated age of a male at the time of calf conception. In all pairings but one, the males were older than the female (mean age difference = 7.7+ years). Successful males were from two of the four social clusters and males most often mated within their social group or with females from the next geographically closest group. The study combines genetic data with known maternal pedigree information and reveals patterns in the overall mating system in a cetacean species where reproductive success of males was previously unknown.


Author(s):  
Sergio E. Cobarrubia-Russo ◽  
Guillermo R. Barreto-Esnal ◽  
Alimar E. Molero-Lizarraga ◽  
Miguel A. Mariani-Di Lena

AbstractThe coast of Aragua is a home of bottlenose dolphins (BND), Atlantic spotted dolphins (ASD) and fishermen (FIS) from four towns. A photo-identification study was carried out on BND to estimate their home ranges. From 2004 to 2008, 100 field surveys were carried out along 30 km of coastline (92.12 km2). In each sighting of BND, information regarding date, time, latitude/longitude and photographs were registered (ASD and FIS were registered without photography). The data were analysed using a Geographic Information System to estimate Minimum Convex Polygon (MCP) and Fixed Kernel (FK) at 95%. The home ranges of BND were estimated for seven individuals. This included three females (29–31 sightings) with estimated areas ranging from 33.90–39.90 km2 with MCP (36.79–43.31% of the study area) and from 80.47–101.31 km2 with FK (109.97–104.26%). For the remaining four dolphins (14–20 sightings) the estimated areas ranged from 9.67–22.34 km2 (MCP), the predominant depth of these home ranges varied from 51–100 m (χ2 = 24.5, df = 2, P = 4.785 × 10−6). For the pods of ASD the estimated area ranged 75.23 km2 with MCP (81.66%) and 119.86 km2 with FK (130.11%) with predominant depths of 101–200 m (χ2 = 24.5, df = 2, P = 4.785 × 10−6). The area used by FIS ranged 93.27 km2 by MCP and 228.49 km2 by FK. Finally, the overlap area of BND, ASD and FIS ranged 24.75 km2 (26.86%). We point out this locality presents important oceanographic and ecological aspects which deserve to be the subject of application of management plans for the conservation of its habitat and species.


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