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The Bahamas’ Atlantic Spotted Dolphins
Research on Communication: how dolphins share information using behavior, postures, and sounds

Background details
An aquatic lifestyle has resulted in the evolution of unique adaptations for signal exchange (communication) among dolphins. Signals may be expressed via physical, acoustic, or visual contact. Signals may be used singly or concurrently depending on the intended message. Atlantic spotted dolphins (Stenella frontalis) in the Bahamasuse a variety of signals (behaviors, vocalizations, and postures) to exchange information and these signals vary according to dolphin age, sex, behavioral activity, and group type.

Study Site: Mikura Island
Mikura Island is a dormant volcano likely thousands of years old. While the near shore area is shallow (4 to 20 m), depths of over 100 m can be found within 150 m of shore. The coast is lined with boulders and pebbles. The Kuroshio current annually encompasses the island in its northerly flow and brings a variety of fish. Due to the deep waters nearby, the effect resembles an upwelling near the island. Thus, fish species are abundant.

The Island
The island, or more accurately islands, of Bimini lie less than 50 miles off the east coast of Florida.  In fact, if you look to the west after sunset, you can see the lights of Miami.
Bimini may be just a 20 minute plane ride from the U.S., but this most westerly inhabited island of the Bahamas is a world away.  Only a few hundred yards wide in some areas, Bimini is known for fishing, SCUBA diving and, of course, dolphins.
 
The Water
Bimini lies at the northwestern edge of the Great Bahama Bank, a vast area of

In January 2007, colleagues from Sweden joined Dudzinski during data collection at Dolphin Encounters for an exiting new research collaboration. Drs. Mats Amundin and Christer Blomqvist, and two of Mats’ graduate students, joined DCP at Dolphin Encounters to implement use of the MOSART tag (housed in pec packs worn by dolphins) and their newly designed and built ELVIS system.

A Brief History
Over 35 Species of cetacean have been maintained in artificial environments since the early 1860’s.  While descriptions of specific behaviors were first provided by Townsend (1914), the majority of information collected on captive dolphins has focused on collection, transport, husbandry and medicine (Defran & Pryor, 1980). One would also expect to find a rich literature on species-typical or comparative behaviors of captive cetaceans; however, the published accounts for this topic are limited in number.

Association patterns: Measuring frequency, duration and proximity between dolphin calves and associates in Roatan, Honduras and Bimini, The Bahamas

Dolphin calves typically bond with other individuals in the group in which they live.From these associates, calves learn survival skills and social behaviors such as foraging,play behaviors, and signals used to share information as well as the overall socialstructure of the group. During the Dolphin Communication Project’s data collection,calves of three delphinid species have been observed to associate with different individual dolphins, not limited to their mothers. A few researchers (Herzing, 1990;Mann, Janet; Masaki, et al.

Interspecific interactions and hybridization in marine mammals
Interspecific interactions, mating attempts and hybridization have been observed in both terrestrial and marine populations (Baird et al. 1998).  Hybridization among marine mammals is a little understood, but increasingly observed, phenomenon between unrelated yet overlapping populations (Baird et al. 1998, Dohl et al. 1974, Herzing et al. 1997).  This research documents interactions, particularly mating behaviors, between common bottlenose (Tursiops truncatus) and Atlantic spotted (Stenella frontalis) dolphins off Bimini, The Bahamas and examines the possible mechanisms driving these interactions.

Do dolphins eavesdrop on the echolocation signals of other dolphins?
It has been suggested that dolphins are able to eavesdrop on the echolocation signals of other dolphins, and, by doing so, are able to acquire object and environmental information without needing to use their own echolocation. This is known as the ‘echoic eavesdropping’ hypothesis. According to the results of one experiment, it appears that this might indeed be something that dolphins are capable of doing.

Update: Spring 2009
The most recent paper on our pectoral fin contact study was published in Behavioural Processes early this year. The PDF is posted to the Publications page of our web site.
How & Why do Dolphins use their Pectoral Fins? Are there single or multiple functions for flipper contact?
Dr. Dudzinski is examining how dolphins exchange pectoral fin contact.