Global and regional variation in the biology and behavior of bottlenose dolphins /
Three separate investigations designed to explore ences". global and regional variation in the biology and behavior of bottlenose dolphins (Tursiops truncates) were conducted. The objective of this research was to examine the influence of habitat characteristics on the behavior and external mor...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=732834511&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Three separate investigations designed to explore ences". global and regional variation in the biology and behavior of bottlenose dolphins (Tursiops truncates) were conducted. The objective of this research was to examine the influence of habitat characteristics on the behavior and external morphology of free-ranging dolphins. Geographic variation in dorsal fin shape of eight dolphin populations from around the world was assessed by examining high quality photographs of 347 individuals. The use of photogrammetric techniques combined with discriminant function analysis proved useful in differentiating between populations. Correct classification rates for two models comparing eight regions and four regions ranged from 51.0% to 83.4%, respectively. It was hypothesized that variation in dorsal fin shape may reflect cline adaptations to local habitat conditions, or be indicative of a genetic characteristic representative of particular breeding stocks. Age and sex class differences in dorsal tin size and notching were investigated in a separate investigation. The objective of this study was to evaluate gender and maturational differences in dorsal fin notching, and to examine the potential for sexual dimorphism in the dorsal tin. Gender-based differences in notching and proportional fin size werenot found. However, maturational differences in notching were significant, and indicated that immature dolphins had substantially less dorsal notching than their mature counterparts. Finally, a longitudinal study of bottlenose dolphins inhabiting the dynamic coastal ecosystem of Kansas Pass, Texas, was conducted between 1991-1997. Research objectives were to examine the occurrence, site fidelity, and behavior of bottlenose dolphins relative to seasonal changes in habitat characteristics. During 79 photo-identification surveys totaling over 1037 h of effort, 9286 dolphins in 1585 schools were encountered, and 782 individuals identified. Significant seasonal variability in abundance, behavior, school size, and calf proportions were documented, and were hypothesized to reflect behavioral adjustments influenced by the inconsistent nature of the study area. Results from these studies indicate that the interplay between environment, physiology, and behavior is likely to contribute to the intraspecific variation commonly observed for bottlenose dolphins. |
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| Item Description: | Vita. |
| Physical Description: | xii, 142 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references: pages 102-113. |