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How many males are there? An examination of operational sex ratio within marine turtle nesting populations in southern Florida.
Title
How many males are there? An examination of operational sex ratio within marine turtle nesting populations in southern Florida.
Creator
Lasala, Jacob, Wyneken, Jeanette, Graduate College
Abstract/Description
Characterizing a species mating system is integral to understanding its natural history and is critical to the development of effective conservation strategies. A mating system is typically described by examining a single population and subsequently drawing inferences on the whole of the species. Variation among populations and gaps in understanding of a species often are revealed when studies are compared between several locations. The majority of available marine turtle mating system data...
Show moreCharacterizing a species mating system is integral to understanding its natural history and is critical to the development of effective conservation strategies. A mating system is typically described by examining a single population and subsequently drawing inferences on the whole of the species. Variation among populations and gaps in understanding of a species often are revealed when studies are compared between several locations. The majority of available marine turtle mating system data stem from nesting females or hatchlings scurrying off the beach. This practice left glaring holes in the understanding of these imperiled organisms in particular with respect to males. We use exclusion paternity analysis to compare the genotype of a nesting female with genotypes from a subset of her offspring and deduce male genotypes to identify and count the number of males contributing per clutch. Loggerheads Caretta caretta, green turtles Chelonia mydas and tleatherbacks Dermochelys coriacea are protected species with spatially and temporally overlapping nesting beaches. The genotypes of the three species nesting in southern Florida will be compared among clutches to define mating systems. Additionally, we will provide the first measure of operational population size for both males and females in southern Florida. Finally, by comparing results from several beaches, the interconnectedness of rookeries through male-mediated gene flow will be determined as well as the relatedness of males. Our approach to establishing the mating systems of hard-to access-life stages will have strong conservation value in strengthening the demographics that form the core of species assessment and management.
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00005155
Format
Document (PDF)
Breeding sex ratios of three imperiled marine turtles nesting in southern Florida
Title
Breeding sex ratios of three imperiled marine turtles nesting in southern Florida.
Creator
Lasala, Jacob, Hughes, Colin, Wyneken, Jeanette, Graduate College
Abstract/Description
Sound assessment of the status of a threatened or endangered organism depends on understanding key aspects of behavior throughout its life history. Sometimes organisms can be difficult to observe and key aspects of behavior may not be accessed directly. Alternative assessment techniques include using molecular markers to identify fundamental relationships among males and females. In the context of assessing the status of imperiled populations’ sex ratios, population size and the relatedness...
Show moreSound assessment of the status of a threatened or endangered organism depends on understanding key aspects of behavior throughout its life history. Sometimes organisms can be difficult to observe and key aspects of behavior may not be accessed directly. Alternative assessment techniques include using molecular markers to identify fundamental relationships among males and females. In the context of assessing the status of imperiled populations’ sex ratios, population size and the relatedness of the individuals are important metrics. Environmental sex determination directs developing marine turtle sex so that primary sex ratios depend upon weather and climate; those sex ratios are estimated by proxies. Adult population sizes are inferred from numbers of females nesting on the beach, but numbers of males are unknown. Male breeding population size can be estimated from subtracting maternal genotypes from genotypes of offspring exclusion analyses. The resulting adult sex ratios differ greatly from those estimated for hatchlings. To refine current adult sex ratios in ways that are relevant to production of future generations and add to our understanding of effective population size we compare the breeding sex ratios the number of males and females contributing to a population of three species of sea turtles nesting in southern Florida. We will use the same genetic data to measure relatedness of the female nesters and the male contributors and describe how that relates to genetic flow and population structure.
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Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00005893
Format
Document (PDF)