Abstract

Sea turtle foraging has been widely documented across the globe. However, there are still some regions where foraging descriptions are lacking. Additionally, it remains unknown if intersexual resource partitioning occurs within populations, which may in part be due to difficulty in identifying the sex of individuals, since juvenile turtles lack sexual dimorphism. The hawksbill (Eretmochelys imbricata) sea turtle is known to be a spongivore throughout the Caribbean, yet has been observed foraging on algal, crustacean, and zoanthid prey items. Most such studies have been conducted in the eastern Caribbean, leaving much to be discovered in the western Caribbean, specifically along the eastern coast of Central America. Previous studies have described hawksbill prey item use, yet few describe prey item energy content, and none describe potential intersexual resource partitioning. Some studies have identified prey items by sex of the turtle, but do not further investigate potential resource partitioning. In this dissertation, I used citizen-science data to identify prey items within juvenile hawksbill home ranges, measured energy content as a possible explanation for prey selection, and analyzed prey selection in relation to hawksbill sex in an attempt to understand if resource partitioning occurred in the SBWEMR. I found juvenile hawksbills in the SBWEMR selected the sponge Geodia neptuni and the alga Kallymenia limminghii as prey items within their home ranges. Although both prey items had relatively low average energy content (11 – 17 kJ g-1), energy intake may be compensated by the abundance of G. neptuni. Furthermore, I hypothesize that hawksbills selected K. limminghii to provide essential nutrients that may not be available in G. neptuni. Finally, I was unable to identify any evidence of intersexual resource partitioning, since both G. neptuni and K. liminghii were found equally in juvenile hawksbill diet samples. Although resource partitioning did not appear to be a factor in the success of juvenile SBWEMR hawksbills, partitioning may become important in later life stages, when females require energy and fat stores lost during nesting. Collectively, these studies aid conservation managers in designing strategies to protect hawksbill foraging grounds, and help us understand how juvenile hawksbills select and utilize prey items.

LLU Discipline

Biology

Department

Biology

School

School of Medicine

First Advisor

Stephan G. Dunbar

Second Advisor

Ronald Carter

Third Advisor

Bill Hayes

Fourth Advisor

Kevin Nick

Fifth Advisor

Ernest Schwab

Sixth Advisor

Kenneth Wright

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2020

Date (Title Page)

5-2020

Language

English

Library of Congress/MESH Subject Headings

Hawksbill turtle--Caribbean Sea; Animals -- food.

Type

Dissertation

Page Count

xvii, 228 p.

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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