Residence patterns of the Guiana dolphin <i>Sotalia guianensis</i> in Babitonga bay, south coast of Brazil


  • F. A. S. Hardt
  • M. J. Cremer
  • A. J. Tonello, Jr.
  • P. C. A. Simões-Lopes



Photo-identification and video-identification techniques were applied to study the residence of Sotalia guianensis in the Babitonga Bay, north coast of Santa Catarina State. From November 2000 to February 2003 a photo-identification effort was conducted trough 21 months, with additional video-identification conducted from August 2003 to August 2004, totalling 34 months of identification effort. Fifty-one different animals were identified with residence rates varying from 2.9% (n = 1 sighting) to 67.6% (n = 23 sightings). During the four years it was found that more than 30% (n = 16) of identified individuals were observed during three years, and 25% (n = 13) only were seen within one year. Considering previous studies, the longest period of residence reached eight years for one individual. Due to the high rates of resightings observed for most of the animals and the small percentage of animals only seen once, it is clear that S. guianensis is resident year-round in the studied area.