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

During the summers of 1988 and 1989, nests of 528 loggerhead sea turtles (Caretta caretta), 27 green sea turtles (Chelonia mydas), and 1 leatherback sea turtle (Dermochelys coriacea) were monitored on Wabasso Beach in Indian River County, Florida. Two hundred and forty four of the loggerhead and 2 of the green sea turtle nests were marked during night surveys as the females laid their clutches, permitting exact clutch counts and carapace measurements on the nesting females. Each marked nest was inspected daily for signs of disturbance and hatching. After incubation (70 days), study nests were excavated and inventoried to determine hatchling emergence success. Parametric multiple regressions, nonparametric multiple regressions, and logistic regressions were used to determine the effects of several measured variables on clutch sizes and incubation times; and nesting, hatchling emergence success, and predation. Excluding the last 2 weeks of the nesting season, nesting was positively correlated with ocean temperatures (P< 0.05), but not with human beach-side development (P> 0.05). Nesting loggerheads on the study area had an average carapace length of 89.8 cm (S.E.=0.31), and a mean clutch size of 112 eggs (S.E.=1.07). Clutches required an average of 53.9 days (S.E.=0.21) to incubate during 1988, with a hatchling emergence success of 57%. During 1989, the mean incubation time and hatchling emergence success was 51.5 days (S.E.=0.21) and 44%, respectively. Over the 2 study years, the average green turtle nest had 118 eggs, took 54.6 days to incubate, and had a hatchling emergence success of 40%. During 1988, 4.6% of the loggerhead nests were lost to beach erosion or alteration (deposition of sand on nests by the surf). This loss was 22% during 1989 for loggerheads, and 30% over both years for green turtles. The difference in loggerhead losses over the 2 years was due to 2 late-season hurricanes which affected the area during 1989. Predation on loggerhead nests was 16% and 8% during 1988 and 1989, respectively. In both years, predation was positively correlated with human beach-side development (P<0.05); during 1989, predation also was positively correlated with distance of the nest from the beach dune (P< 0.05). Clutch size and carapace size of nesting females were positively correlated (P< 0.05). Incubation time was negatively correlated with egg laying date, and hatchling emergence success was strongly affected by the late summer storms of 1989. The study area produced an estimated 70,469 loggerhead sea turtle hatchlings per year (8,808 hatchlings/km), and 535 green sea turtle hatchlings per year (66 hatchlings/km). The number of loggerhead sea turtle hatchlings produced per nest was adversely affected by beach-side development. / Master of Science

Dry Tortugas National Park (DRTO) consists of 261.8 km2 in the Gulf of Mexico and provides protection to marine species facing a multitude of threats. Among the many species that utilize DRTO is the green sea turtle (Chelonia mydas). I examined seven years of capture-recapture data to determine how the body condition (using Fulton’s equation, K = M/L3) and growth rate for juvenile green turtles vary within, and among size classes in DRTO, and how those rates compare to similar populations in other locations. Body conditions ranged from 0.77 to 1.71 (mean 1.3 SD ± 0.16). Growth rates ranged from 2.5 to 9.9cm/yr (mean 5.5 cm/yr SD ± 1.25), which is a high growth rate for green turtles. Establishing growth rates and body condition for a specific population can provide insight into life history and health of that population, as well as important data for comparison to populations in other areas. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection

There are four distinct subpopulations of loggerhead sea turtles (Caretta caretta) in Florida as determined behaviorally by geographic fidelity, and genetically by mitochondrial haplotypes. The South Florida subpopulation consists of females nesting on the southeastern and southwestern coasts of Florida and their offspring. Previous research shows that west coast hatchlings exhibit higher levels of nocturnal swimming during the postfrenzy period than east coast hatchlings. This study attempted to determine how these differences in migratory behavior develop. A reciprocal translocation experiment was conducted to distinguish between environmental and genetic factors. No consistent differences in hatchling swimming behavior were seen based on geography. Movement of nests resulted in lower levels of nocturnal swimming behavior in hatchlings compared to hatchlings that emerged from natural nests, suggesting that the relocation of nests may not provide a natural incubation environment for developing hatchlings. / by Jeffrey Guertin. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

In April of 1990 the Sebastian Inlet Tax District received a long-term (25 year) permit to conduct maintenance dredging of the navigation channel at Sebastian Inlet, Florida. Approximately 105,150 cubic meters of sediment will be removed every two years and pumped to a feeder beach immediately south of the inlet. The renourished beach, a high density nesting beach for loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles, is within the proposed Archie Carr National Wildlife Refuge and will play a critical role in the long-term maintenance of Sebastian Inlet as a navigable waterway. A turtle monitoring program was implemented by the District at the request of the U.S. Fish and Wildlife Service. The monitoring program was designed to investigate nesting behavior, reproductive success and physical characteristics of the nesting habitat on the renourished beach at Sebastian Inlet and on a control beach (Wabasso Beach). Daily nesting surveys were conducted to record all sea turtle nests and non-nesting emergences in each study area. All nests were marked, monitored throughout incubation and inventoried to determine hatching and emergence success. Data on physical parameters were collected in monthly profiles of each beach. Compaction values were recorded with a cone penetrometer along transects from the dune to mean high water line. Temperature of the ambient beach was recorded at 30 and 60-cm depths along two transects from the dune to mean high water line. Moisture and sand grain analysis were conducted monthly in 1991. Sea turtle nesting and hatching success were similar on the renourished and control beaches in 1990 and 1991, suggesting that renourishment had no adverse effect on sea turtle reproductive success. Nesting success on the renourished and control beaches, respectively, was 42.0% (N = 104) and 45.0% (N = 65) in 1990, and 62.9% (N = 165) and 62.4% (N = 118) in 1991. Hatching success on the renourished and control beaches, respectively, was 80.7% (N = 85) and 79.3% (N = 59) in 1990, and 69.1% (N = 118) and 66.7% (N = 102) in 1991. Compaction values averaged 500 PSI on the renourished beach, while values on the control were approximately 250 PSI. The higher level of compaction on the renourished beach resulted in a lack of complete nest covering, and aberrant nest chamber configurations on the renourished beach. Grain size and moisture content were similar on the renourished and control beaches. Compaction levels were not related to incompatible fill, implying that the manner in which the material was deposited resulted in the increased compaction. Beach temperatures measured at 30-cm and 60-cm depths indicated that the renourished beach was consistently 0.5°C warmer than the control beach. If the physical parameters of a subsequent renourishment project are within the findings of 1990 and 1991, there should be no adverse effect on sea turtle nesting and hatching success. The results of this project cannot be applied to other beach renourishment projects however, but should be restricted to future dredging projects at Sebastian Inlet. Although the results are not applicable to other locations, the methodologies developed to study the effects of renourishment on sea turtles could be applied to other beach renourishment situations. Future research should focus on how the physical parameters of a renourished beach affect the micro-environment within the actual nest chamber and embryonic development. / Master of Science

The red imported fire ant, Solenopsis invicta, is a South American native introduced in Alabama in the early 20th century. This predatory species has rapidly spread throughout the southeastern US and parts of the West Indies, inflicting great ecological and economic damage. For example, Solenopsis invicta is known to attack the eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests attacking hatchlings and diminishing their chance for survival. My thesis research aimed to survey the distribution of ants on sea turtle nesting beaches in South Florida and St. Croix, USVI, and to evaluate the possible threat of Solenopsis invicta and other predatory ants to sea turtle hatchlings. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.