INTEGRATION OF A BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) MOTHER AND CALF DYAD TO A SOCIAL GROUP OF CETACEANS

The aims of this research were to study the integration of a mother and her six month old calf to the community of cetaceans hosted at Oltremare Park. The present social group consist a juvenile female Risso’s dolphin and 6 bottlenose dolphins (one adult male, 4 adult females and the male calf). Observations were performed between 17th November 2010 and 27th February 2011 for a total amount of 70 hours. Data were sampled utilizing Focal Animal Sampling and recorded using the Continuous Recording. The integration process consisted of four different phases to minimize potential aggression toward the calf. Many social interactions were observed with a diversity of social displays. Social interactions were studied by quantitative analysis of the affiliative, agonistic and sexual interactions between the dyad and the rest of the group. Affiliative interactions within the dyad remained higher for all the period, but were also noticed between calf and another adult female. Agonistic interactions within the dyad and toward another adult female occurred to establish control of the calf. Sexual interactions were registered since the second to fourth phase between the calf and his mother, but also between the calf and another adult female. The integration between the dyad and the dominant male occurred without agonistic display between the animals.