Date of Award

Fall 12-2016

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

Committee Chair

Donald Sacco

Committee Chair Department

Psychology

Committee Member 2

Heidi Lyn

Committee Member 2 Department

Psychology

Committee Member 3

Bandana Kar

Committee Member 3 Department

Geography and Geology

Committee Member 4

Frank Moore

Committee Member 4 Department

Biological Sciences

Abstract

Information on the habitat use of a species is important to develop conservation efforts and management strategies for that species. Roanoke Sound, North Carolina is primarily a seasonal habitat for bottlenose dolphins, Tursiops truncatus, from late spring to early fall, but little information is known about how dolphins use this area. Transect survey data and opportunistic survey data collected by the Outer Banks Center for Dolphin Research from 2009 to 2015 were used to analyze dolphin habitat use. The objectives of this project were to: 1) identify areas that were important to dolphins, 2) determine which behaviors were observed in these areas and whether dolphin groups with calves used these areas, 3) compare the results from opportunistic surveys to the results from transect surveys to determine their reliability, and 4) determine if environmental variables influence dolphin density. The Hot Spot Getis-Ord Gi* spatial statistic was used to identify areas of significant use. Transect hot spots in the southern part of Roanoke Sound were used for feeding, traveling, and by dolphin groups with calves. Most opportunistic hot spots were in the boat channel and were affected by survey bias. To improve validity of hot spots using opportunistic survey data, weighted behavioral rates were examined. From opportunistic data, this analysis identified a feeding hot spot in the middle boat channel and milling hot spots near the mouth of an estuary. Environmental variables did not significantly influence transect dolphin group density. The hot spot results suggest that the southern part of Roanoke Sound serves as a seasonal feeding habitat and a transit route between the inshore estuaries and the Atlantic Ocean. This study is the first to analyze dolphin habitat use in Roanoke Sound and provides valuable information on dolphin foraging sites, transit areas, and potential calf nursery areas for conservation and stock management in this area. This study also presents a new analysis that may be used to examine habitat use with presence-only data.

ORCID ID

0000-0003-0973-2761

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