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Behavioral Change and Phenological Response in Captive Loggerhead Sea Turtles (Caretta caretta): Seasonal Patterns and the Migratory Process

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Date Issued:
2018-11-28
Abstract/Description:
Understanding vital life history processes is critical to the conservation and management of endangered species, especially in light of changing global climate conditions and the verging unknown impacts this will have on these mechanisms. The goal of this study was to employ direct observation methods on captive loggerhead sea turtles (Caretta caretta) to examine behavioral change as a proxy for the reproductive migratory process. Diurnal and nocturnal observations were conducted on two mature female loggerheads housed at Mote Marine Laboratory in Sarasota, Florida, from December 2013 through December 2015. Both turtles displayed a reduced interest in food during the winter season each year, which lasted approximately 11 weeks in 2014 and 14 weeks in 2015, with a five week difference in timing between individuals. This time period corresponded with observed change in activity levels, swim patterns, interactions, and location preferences for both animals. There was a rise in diurnal resting, coinciding with a decrease in diurnal swimming as well as a decrease in interactions with their environment. Activity levels increased at night, with some nights of prolonged heightened swimming episodes. One of the turtles exhibited a swim pattern of fixated, directional movement into the wall at increased frequency during this time frame. Both animals spent the majority of their time in a small section of their habitat proximal to the open sky. Three environmental variables (air temperature, photoperiod, and lunar phase) were tracked during this study to investigate potential zeitgebers in sea turtles. Patterns indicate a possible response to day length and stage of the moon, though these findings are speculative and require further research. Behavioral changes noted here suggest that reproductively mature sea turtles display a form of migratory restlessness in a captive setting, and turtles may utilize a nocturnal swimming strategy during the pre-nesting migration. This study highlights the importance of direct observations when examining behavior and the benefits of using captive animals to help understand processes that are difficult to investigate in the wild.
Title: Behavioral Change and Phenological Response in Captive Loggerhead Sea Turtles (Caretta caretta): Seasonal Patterns and the Migratory Process.
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Name(s): Shaw, Amber, author
Type of Resource: text
Genre: Thesis
Issuance: single unit
Date Issued: 2018-11-28
Physical Form: PDF
Extent: 82 pgs.
Language(s): English
eng
Abstract/Description: Understanding vital life history processes is critical to the conservation and management of endangered species, especially in light of changing global climate conditions and the verging unknown impacts this will have on these mechanisms. The goal of this study was to employ direct observation methods on captive loggerhead sea turtles (Caretta caretta) to examine behavioral change as a proxy for the reproductive migratory process. Diurnal and nocturnal observations were conducted on two mature female loggerheads housed at Mote Marine Laboratory in Sarasota, Florida, from December 2013 through December 2015. Both turtles displayed a reduced interest in food during the winter season each year, which lasted approximately 11 weeks in 2014 and 14 weeks in 2015, with a five week difference in timing between individuals. This time period corresponded with observed change in activity levels, swim patterns, interactions, and location preferences for both animals. There was a rise in diurnal resting, coinciding with a decrease in diurnal swimming as well as a decrease in interactions with their environment. Activity levels increased at night, with some nights of prolonged heightened swimming episodes. One of the turtles exhibited a swim pattern of fixated, directional movement into the wall at increased frequency during this time frame. Both animals spent the majority of their time in a small section of their habitat proximal to the open sky. Three environmental variables (air temperature, photoperiod, and lunar phase) were tracked during this study to investigate potential zeitgebers in sea turtles. Patterns indicate a possible response to day length and stage of the moon, though these findings are speculative and require further research. Behavioral changes noted here suggest that reproductively mature sea turtles display a form of migratory restlessness in a captive setting, and turtles may utilize a nocturnal swimming strategy during the pre-nesting migration. This study highlights the importance of direct observations when examining behavior and the benefits of using captive animals to help understand processes that are difficult to investigate in the wild.
Identifier: fgcu_ETD_0262 (IID)
Note(s): Degree Awarded: Master of Science
Department: Environmental Science
Subject(s): behavior
Migration.
Migratory restlessness
Sea turtles
zeitgeber
Persistent Link to This Record: http://purl.flvc.org/fgcu/fd/fgcu_ETD_0262
Use and Reproduction: Creator holds copyright.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FGCU