Pectoral Fin Study

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. That is, how do dolphins touch or rub each other with their flippers? Is the exchange of flipper rubs affiliative or agonistic? Or, is there some other function; could flipper rubs just feel good? Or maybe flipper contact gets an itch or removes sloughing skin? How, when, and with whom do dolphins exchange pectoral fin rubs? Does use of a pectoral fin as a signal need to be learned by young dolphins? That is, what is the development of this contact behavior as a signal? These are just some of the general questions Dudzinski poses with respect to contact behavior between two dolphins, focusing specifically on pectoral fin touches and rubbing behavior.

Dr. Dudzinski, with DCP volunteers and interns, are cataloging video data gathered from the Bahamas’ Atlantic spotted dolphins and Indo-Pacific bottlenose dolphins around Mikura Island, two dolphin species in radically different environments, with respect to their contact via pectoral fins. She is also including data collected on the bottlenose dolphins from Roatan Institute for Marine Sciences and Dolphin Encounters. All of our data is sampled for all cases of pectoral fin touches/rubs and will be compared within and between groups.

A few examples of some of our more specific questions related to our study of dolphin pectoral fin use and function follow. We will post results as the data are processed and statistics are completed. We will also include progress reports in the Dolphin Gazette.

  • Do dolphins use their pectoral fins preferentially to touch other’s body parts? Is one body part touched more than any other? If so, what might this depend upon: context, rubber/rubbee ID, sex, age?
  • Does the rubber or the rubbee initiate pectoral fin touches?
    The “rubber” is defined as the dolphin with pectoral fin touching another dolphin.
    The “rubbee” is defined as the dolphin whose body is rubbed by the pectoral fin.
  • When is the rub initiated (time of day)?
  • Is there a diurnal pattern?
  • Is there a seasonal pattern?
  • Who rubs whom? Is there a difference when different dolphins are involved: mother/calf pairs, adult females, adult males, juveniles?
  • Is pectoral fin rubbing reciprocal? Do dolphins take turns and if so, is their turn taking related to age or sex or behavior? How many reciprocal pairs are in the data set?

Pec rubbing