Exodus! Large-scale displacement and social adjustments of resident Atlantic spotted dolphins (Stenella frontalis) in the Bahamas.

Over the last 20 years, significant habitat shifts have been documented in some populations of cetaceans. On Little Bahama Bank (LBB) there are sympatric communities of resident Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus), monitored since 1985. The size and social structure (three clusters: Northern, Central, Southern) have been stable among the spotted dolphin community with little immigration/emigration, even after large demographic losses (36%) following two major hurricanes in 2004.

Molecular assessment of mating strategies in a population of Atlantic spotted dolphins.

Similar to other small cetacean species, Atlantic spotted dolphins (Stenella frontalis) have been the object of concentrated behavioral study. Although mating and courtship behaviors occur often and the social structure of the population is well-studied, the genetic mating system of the species is unknown. To assess the genetic mating system, we genotyped females and their progeny at ten microsatellite loci.

Evidence of teaching in Atlantic spotted dolphins (Stenella frontalis) by mother dolphins foraging in the presence of their calves.

Teaching is a powerful form of social learning, but there is little systematic evidence that it occurs in species other than humans. Using long-term video archives the foraging behaviors by mother Atlantic spotted dolphins (Stenella frontalis) were observed when their calves were present and when their calves were not present, including in the presence of non-calf conspecifics. The nine mothers we observed chased prey significantly longer and made significantly more referential body-orienting movements in the direction of the prey during foraging events when their calves were present than when their calves were not present, regardless of whether they were foraging alone or with another non-calf dolphin.

The broadband social acoustic signaling behavior of spinner and spotted dolphins.

Efforts to study the social acoustic signaling behavior of delphinids have traditionally been restricted to audio-range (<20 kHz) analyses. To explore the occurrence of communication signals at ultrasonic frequencies, broadband recordings of whistles and burst pulses were obtained from two commonly studied species of delphinids, the Hawaiian spinner dolphin (Stenella longirostris) and the Atlantic spotted dolphin (Stenella frontalis). Signals were quantitatively analyzed to establish their full bandwidth, to identify distinguishing characteristics between each species, and to determine how often they occur beyond the range of human hearing.

Echolocation signals of wild Atlantic spotted dolphin (Stenella frontalis).

An array of four hydrophones arranged in a symmetrical star configuration was used to measure the echolocation signals of the Atlantic spotted dolphin (Stenella frontalis) in the Bahamas. The spacing between the center hydrophone and the other hydrophones was 45.7 cm.