Emilie Olivier Abstract Undergrad

Citation: Olivier, E. (2006) Movement Patterns of a population of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Mikura Island, Japan, in relation to age and gender. Unpublished Bachelors Thesis, School of Marine Sciences, University of Maine.

Abstract:
Indo-Pacific bottlenose dolphins (Tursiops aduncus) exhibit complex ranging behavior (Hastie et al., 2003).  The size of an individual’s range is partially dependent on the gender or age of the individual, and is based on competition for females and foraging access (Kogi et al., 2004).  Male individuals usually defend larger ranges for more access to females (Owen et al., 2002).  Sighting data for individually identified dolphins collected in 2001 were tested for a possible correlation between movement patterns and age or gender of the resident Tursiops aduncus. Location sighting data were categorized into 13 equally sized distances around Mikura Island and individual dolphins were documented as having been observed in one of these areas.  Attention was focused on any preferential selection of a specific location or area around the island.  There was no significant correlation found between movement patterns and age or gender of individual dolphins, indicating that Tursiops aduncus’s movement patterns are related to other factors, such as prey movement, habitat quality, and social interactions (Natoli et al., 2005, Shane et al., 1986).  The small size of the island relative to the study population’s range and the small time period of the study may have influenced the results of the study.  Further study including a longer time period or larger study area would allow us to determine the extent of any possible correlations between movement patterns around Mikura Island and the age or gender categories of Tursiops aduncus observed frequently within 300 m of the island’s coastline.

References

Hastie, Gordon D.; Wilson, Ben; and Thompson, Paul M.  2003.  Fine-scale habitat selection by coastal bottlenose dolphins: application of a new land-based video-montage technique.  Canadian Journal of Zoology 81: 469-478

Kazunobu, Kogi; Toru, Hishii; Imamura, Ayami; Iwatani, Takako; Dudzinski.  Kathleen.  2004.  Demographic parameters of Indo pacific bottlenose dolphins (Tursiops aduncus) around Mikura Island, Japan.  Marine Mammal Science 20: 510-526

Natoli, Ada; Birkon, Alex; Aguilar, Alex; Lopez, Alfredo; and Hoelzel A. Rus.  2005.  Habitat structure and the dispersal of male and female bottlenose dolphins (Tursiops truncatus).  Proceedings of the Royal Society 272: 1217-26

Owen, Edward C. G.; Wells, Randall S.; and Hofmann, Sue.  2002.  Ranging and association patterns of paired and unpaired adult male Atlantic bottlenose dolphins, Tursiops truncatus, in Sarasota, Florida, provide no evidence for alternative male strategies.  Canadian Journal of Zoology 80: 2072-2089

Shane, Susan H.; Wells, Randall S.; and Wursig, Bernd.  1986.  Ecology, behavior, and social organization of the bottlenose dolphin: a review.  Marine Mammal Science.  2: 34-63