Current Search: Sex ratio (x)
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Title
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AN ANALYSIS OF THE GEOGRAPHY OF SEX RATIO IN THE UNITED STATES.
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Creator
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GELLIS, ANDREW NOAH., Florida Atlantic University, Lee, David R., Charles E. Schmidt College of Science, Department of Geosciences
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Abstract/Description
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Frontier areas and rural areas historically have been predominantly male (high sex ratio); urban areas were predominantly female (low sex ratio). In 1970 the Middle West scored average on the sex ratio scale for all age cohorts; the West was high, the South low. Highest sex ratio was in port and military locales; lowest was in urban areas of the Northeast and South. Two regression models reveal that percentage urban, net migration, and percentage Black were most important explanators of sex...
Show moreFrontier areas and rural areas historically have been predominantly male (high sex ratio); urban areas were predominantly female (low sex ratio). In 1970 the Middle West scored average on the sex ratio scale for all age cohorts; the West was high, the South low. Highest sex ratio was in port and military locales; lowest was in urban areas of the Northeast and South. Two regression models reveal that percentage urban, net migration, and percentage Black were most important explanators of sex ratio. The greater life expectancy of females and their tendency to concentrate in the cities, the larger net migration rate of males, and the lower sex ratio of Blacks, were causal. Analysis by age cohort revealed regional differences exist only after age 34. After adjusting for the above independent variables, the West still scored highest and the South lowest.
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Date Issued
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1981
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PURL
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http://purl.flvc.org/fcla/dt/14061
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Subject Headings
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Sex ratio, United States--Population
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Format
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Document (PDF)
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Title
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Identifying mating systems of imperiled marine turtles nesting in southern Florida through exclusion analysis to estimate the breeding sex ratio.
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Creator
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Lasala, Jacob A., Wyneken, Jeanette, Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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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....
Show moreThe 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.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013161
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Subject Headings
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Sea turtles--Florida, Mating behavior, Sex ratio
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Format
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Document (PDF)
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Title
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Sex ratio and crime: A cross-cultural investigation.
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Creator
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Hitchell, Amanda R., Florida Atlantic University, Shackelford, Todd K.
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Abstract/Description
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When one sex outnumbers the other in a society, what are the social consequences? Sex ratio, or the number of men per 100 women in a society, may affect many aspects of society such as crime rates. It was predicted that in countries with higher sex ratios, crime rates would be higher than in countries with lower sex ratios. It was also predicted that in countries with higher sex ratios, homicide and rape rates would be higher than in countries with lower sex ratios. Additionally, it was...
Show moreWhen one sex outnumbers the other in a society, what are the social consequences? Sex ratio, or the number of men per 100 women in a society, may affect many aspects of society such as crime rates. It was predicted that in countries with higher sex ratios, crime rates would be higher than in countries with lower sex ratios. It was also predicted that in countries with higher sex ratios, homicide and rape rates would be higher than in countries with lower sex ratios. Additionally, it was predicted that in countries with lower sex ratios, the incidence of female offending would be higher than in countries with higher sex ratios. Adult sex ratios and crime statistics were collected for 154 countries and for each of eight years. The prediction that crime rates would be higher in countries with higher sex ratios was partially supported by the data, as was the prediction that rape rates would be higher in countries with higher sex ratios. The prediction that homicide rates would be higher in countries with higher sex ratios was contradicted by the data, and mixed results were found for the prediction that the incidence of female offending would be higher in countries with lower sex ratios. Limitations are discussed, as are possible directions for future research.
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Date Issued
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2004
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PURL
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http://purl.flvc.org/fcla/dt/13192
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Subject Headings
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Family violence--Cross-cultural studies, Sex ratio--Research, Sex and law--Cross-cultural studies, Female offenders
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Format
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Document (PDF)
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Title
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Hatchling sex ratios and nest temperature-sex ratio response of three South Florida marine turtle species (Caretta caretta L., Chelona mydas L., and Dermochelys coriacea V.).
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Creator
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Rogers, Micah Marie., Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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South Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were...
Show moreSouth Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were estimated within biological limitations by both 50-65% of incubation and mean middle 1/3 temperature. The maximum middle 1/3 temperature was the best-fit predictor for green turtles. No best-fit sex ratio-temperature response could be identified for leatherbacks. Clutches incubating under natural conditions can vary greatly in SR ; TRT differences may account for differences among species' sex ratios.
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Date Issued
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2013
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PURL
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http://purl.flvc.org/fcla/dt/3361062
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Subject Headings
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Sex ratio, Sex determination, Genetic, Sea turtles, Nests, Sea turtles, Embryology, Loggerhead turtle, Nests, Loggerhead turtle, Effect of temperature on
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Format
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Document (PDF)
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Title
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Predicting leatherback sea turtle sex ratios using spatial interpolation of nesting beach temperatures.
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Creator
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Weston, Emily G., Wyneken, Jeanette, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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Sex determination in leatherback sea turtles is directed primarily by the temperatures a clutch experiences during the middle third of development. Warmer temperatures tend to produce females will cooler temperatures yield males. Nest temperatures can vary spatially and temporally. During the 2010 and 2011 nesting seasons, this study estimated the hatchling sex ratio of leatherback sea turtles on Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands. I measured sand...
Show moreSex determination in leatherback sea turtles is directed primarily by the temperatures a clutch experiences during the middle third of development. Warmer temperatures tend to produce females will cooler temperatures yield males. Nest temperatures can vary spatially and temporally. During the 2010 and 2011 nesting seasons, this study estimated the hatchling sex ratio of leatherback sea turtles on Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands. I measured sand temperatures from May- August and across the spatial range of leatherback nesting habitat. I spatially interpolated those temperatures to create maps that predicted temperatures for all nests incubating on SPWNR. Nest temperatures were also directly measured and compared with predicted nest temperatures to validate the prediction model. Sexes of dead-in-nest hatchlings and full term embryos were used to confirm the sex-temperature response. The model showed that microclimatic variation likely impacts the production of both sexes on SPNWR.
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Date Issued
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2013
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PURL
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http://purl.flvc.org/fau/fd/FA0004071
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Subject Headings
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Leatherback turtle -- Habitat -- St. Croix -- Sandy Point National Wildlife Refuge (United States Virgin Islands), Loggerhead turtle -- Effect of temperature on, Sandy Point National Wildlife Refuge (United States Virgin Islands), Sea turtles -- Nests -- St. Croix -- Sandy Point National Wildlife Refuge (United States Virgin Islands), Sex determination, Genetic, Sex ratios, Vegetation dynamics
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Format
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Document (PDF)