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Seafinding by the green turtle, Chelonia mydas: the orientation response is tuned to the lighting environment at the nesting beach

Hatchling marine turtles use visual cues to orient from their nest to the sea at
night. However, the wavelengths of light that carry this information have not been
properly documented, nor do we understand why they are favored. I measured
wavelength irradiance at 20 nm intervals between 340 – 600 nm at a dark nesting beach
and then, in the laboratory, determined the thresholds of the hatchlings for each λ that
evoked a positive phototaxis. In this study, I show that green turtle hatchlings are (i) most
sensitive to the shorter (360 – 480 nm) light wavelengths. Those light energies (ii)
dominated the available natural lighting at the nesting beach. They also (iii) presented a
steep gradient in irradiance between a landward and seaward view, an important cue for
orientation. I attribute the phototactic responses to “stimulus filtering”, the outcome of
natural selection that optimizes behavioral responses (seafinding) according to their
function, as well as when and where they occur. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Identiferoai:union.ndltd.org:fau.edu/oai:fau.digital.flvc.org:fau_40786
ContributorsCelano, Lisa (author), Salmon, Michael (Thesis advisor), Florida Atlantic University (Degree grantor), Charles E. Schmidt College of Science, Department of Biological Sciences
PublisherFlorida Atlantic University
Source SetsFlorida Atlantic University
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation, Text
Format43 p., application/pdf
RightsCopyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder., http://rightsstatements.org/vocab/InC/1.0/

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