Current Research
Seasonal abundances and movement patterns of bottlenose dolphins
Very little is known about the population size and identities of bottlenose dolphins that inhabit the waters surrounding the Outer Banks. We believe that the numbers of dolphins in this area change seasonally with the most dolphins occurring in the sounds during the summer. Understanding how population size changes throughout the year can influence important management decisions for conserving bottlenose dolphins. Greater insight into their seasonal movements can illustrate residency patterns and aid in determining intermixing between populations. Our goals are to use dedicated seasonal transect surveys to study changes in population size throughout the year and a combination of dedicated and opportunistic data to determine the identities and residency patterns of dolphins in this area.
Bottlenose dolphins in Roanoke Sound
Bottlenose dolphin social associations
Bottlenose dolphins have been known to exhibit sex-specific social associations. We believe that bottlenose dolphins in the Outer Banks exhibit similar associations to those documented in other areas. In particular, we are interested in examining the presence of male pair bonds within a seasonally resident population. We are also interested in gaining further insight into female-female associations.
Two adult males surfacing together in Roanoke Sound
Skin disease
Various types of skin diseases have been visually documented in bottlenose dolphin communities. Our goal is to characterize types of skin disease observed on dolphins in this area through the use of photo-identification. We are also interested in examining the influence of any potential environmental factors that may affect the prevalence of dolphin skin disease. Bottlenose dolphins that inhabit the northern waters of Roanoke Sound and the Albemarle and Currituck Sounds exhibit an unknown whitish skin disease potentially due to low salinity waters.
Whitish skin disease observed on dolphin
Research Methods
How do we conduct this research on bottlenose dolphins? We use a technique known as photo-identification. Photo-identification is a mark-recapture in which distinguishing markings are used to identify individuals. Bottlenose dolphins acquire distinctive markings on their dorsal fins as they go throughout their lives. We photograph the dorsal fin of each dolphin that we see. Each image is incorporated into a photo-identification catalog along with date, time, and location of where that dolphin has been seen. Over time, we can keep track of how many times we have seen each dolphin, where they were seen, and who they spend time with. We also send our images to the Mid-Atlantic Bottlenose Dolphin Catalog (MABDC), a collaborative effort between researchers along the east coast to better understand movement patterns of bottlenose dolphins.
Conference Presentations:
Taylor, J.W., Olson, J., Bowles, N., and K. Rittmaster. 2011. Association patterns of seasonally resident bottlenose dolphins (Tursiops truncatus) at adjacent North Carolina study sites. Poster presentation at the Southeast and Mid-Atlantic Marine Mammal Symposium, 1-3 April 2011, Coastal Carolina University, Conway, SC.
Research Updates
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