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Identifying mating systems of imperiled marine turtles nesting in southern Florida through exclusion analysis to estimate the breeding sex ratio

The reproductive behavior of migratory organisms is difficult to characterize as
the mating behavior can be difficult to observe. For some species, one sex can be readily
observable, but the other may remain hidden, confounding attempts to assess population
demographics. For such species, it can be difficult to determine the sex ratio of the
population. Without accurate accounts of the numbers of males and females, conservation
methods may be insufficient and their performance unclear. Alternative methods of
measuring sex ratios therefore must be used to estimate the number of individuals and
assess breeding behavior. Here I identified breeding sex ratios (BSR) measured using
paternity analysis of offspring through exclusion analysis to quantify the numbers of
males contributing. Here I discuss the mating behavior of three species of marine turtle
that nest in southern Florida: the loggerhead (Caretta caretta), the leatherback (Dermochelys coriacea), and the green sea turtle (Chelonia mydas) at three beaches
(Boca Raton, Juno Beach, and Sanibel Island) from 2013-2017; over 400 nesting females
were identified and genotyped and almost 7,000 hatchlings were collected and
genotyped. Females from all three species successfully mated with more than one male in
all years analyzed demonstrating multiple paternity of clutches. For loggerheads, many
male genotypes were identified, suggesting that females likely mate en route to their
nesting grounds, inducing a male-biased BSR. Examination of females that were sampled
more than once per season (repeats), evidence of sperm storage was found for all nests
and some turtles might mate in between nesting events. Leatherback females displayed a
higher rate of multiple paternity than was previously published for other Caribbean
nesting sites; I hypothesize that this result may be due to a mainland nesting beach effect.
The leatherback BSR over all years was approximately 1:1, and one male was identified
fathering than two different females’ nests (polygyny). For green turtles, multiple
paternity was found and there was evidence of polygyny. Across all three species,
evidence for indirect benefits of mating multiply (hatching success or larger hatchlings)
was weak or not supported. Together, the four studies contribute to the overall body of
reproductive behavior studies. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Identiferoai:union.ndltd.org:fau.edu/oai:fau.digital.flvc.org:fau_40935
ContributorsLasala, Jacob A. (author), Wyneken, Jeanette (Thesis advisor), Hughes, Colin (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
Format187 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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