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- Title
- Estimating predation levels and site-specific survival of hatchling loggerhead sea turtles (Caretta caretta) from south Florida beaches.
- Creator
- Whelan, Christie L., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
Few studies document mortality rates for hatchling sea turtles during their migration away from the nesting beach. This study quantifies and compares nearshore predation rates on loggerhead hatchlings (Caretta caretta) at several locations in southern Florida. Hatchlings were followed by observers in kayaks during the first 15 min of the migration away from the beach. The overall observed predation rate (4.6%) is similar to a previous estimate (5%) from a natural high density Florida nesting...
Show moreFew studies document mortality rates for hatchling sea turtles during their migration away from the nesting beach. This study quantifies and compares nearshore predation rates on loggerhead hatchlings (Caretta caretta) at several locations in southern Florida. Hatchlings were followed by observers in kayaks during the first 15 min of the migration away from the beach. The overall observed predation rate (4.6%) is similar to a previous estimate (5%) from a natural high density Florida nesting beach, and lower than at a hatchery site. Predation rates were higher on Florida's southeast coast than the southwest coast. Predation increased towards the end of the hatching season. Results suggest that currently, hatchling mortality rates are relative low in Florida's shallow nearshore waters. Given the lack of growth by loggerhead populations, the cumulative mortality must be high after hatchlings depart shallow coastal waters.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13259
- Subject Headings
- Sea turtles--Florida--Atlantic Coast, Loggerhead turtle--Mortality, Predation (Biology)
- Format
- Document (PDF)
- Title
- Comparative studies of retinal design among sea turtles: Histological and behavioral correlates of the visual streak.
- Creator
- DeCarlo, Lisa Joy., Florida Atlantic University, Salmon, Michael, Wyneken, Jeanette
- Abstract/Description
-
We understand very little about the relationships between eye anatomy and visual ecology in sea turtles. Sea turtles use visual information in important contexts, such as selecting habitats, detecting predators, or locating mates or food. This study represents an effort to clarify the form/function relationship between retinal morphology and the behavioral ecology of sea turtle hatchlings. Thus, it is an important first step in relating sea turtle eye anatomy with visual ecology and relating...
Show moreWe understand very little about the relationships between eye anatomy and visual ecology in sea turtles. Sea turtles use visual information in important contexts, such as selecting habitats, detecting predators, or locating mates or food. This study represents an effort to clarify the form/function relationship between retinal morphology and the behavioral ecology of sea turtle hatchlings. Thus, it is an important first step in relating sea turtle eye anatomy with visual ecology and relating the two to sea turtle natural history. Some organisms possess retinas that contain morphologically specialized cellular areas. The "visual streak," is one such area; receptor cells and associated interneurons are concentrated in a horizontal band in the retina. Three species of sea turtles (Chelonia mydas, Caretta caretta, and Dermochelys coriacea) possess a visual streak located along the horizontal mid-line of the retina, although they differed in streak development. The differences in streak development can be related to their ecology.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15548
- Subject Headings
- Sea turtles, Eye--Anatomy, Vision
- Format
- Document (PDF)
- Title
- The risk of hatchling loss to nearshore predators at a high-density loggerhead nesting beach in southeast Florida.
- Creator
- Stewart, Kelly Rhoda., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
It has been recognized that mortality is high for juvenile stages of long-lived vertebrates such as sea turtles, however few studies have quantified mortality rates. The objective of this study was to assess the relative risk that hatchlings face in their first few minutes in the water, at the commencement of their offshore migration from a natural high-density nesting beach (Juno/Jupiter, FL). I followed 217 hatchlings at night by kayak, as they left the beach and documented the proportion...
Show moreIt has been recognized that mortality is high for juvenile stages of long-lived vertebrates such as sea turtles, however few studies have quantified mortality rates. The objective of this study was to assess the relative risk that hatchlings face in their first few minutes in the water, at the commencement of their offshore migration from a natural high-density nesting beach (Juno/Jupiter, FL). I followed 217 hatchlings at night by kayak, as they left the beach and documented the proportion surviving the initial 15 minutes in the water. Of these, 206 survived for an empirical survival rate of 95%. Tarpon were the most common predator observed. This survival rate is much higher than that previously observed at a hatchery (72%); this may be due to temporal and spatial variation in nest location at the natural beach. Juno and Jupiter beaches are therefore highly productive sea turtle rookeries.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12822
- Subject Headings
- Loggerhead turtle--Florida, Sea turtles--Mortality
- Format
- Document (PDF)
- Title
- A seasonal and latitudinal assessment of early growth rates in northern and southeastern loggerhead sea turtles (Caretta caretta L.).
- Creator
- Stokes, Lesley., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
To improve our understanding of loggerhead life history, particularly factors affecting the duration of each age class and survivorship, detailed growth data must be interpreted. The purpose of this study was to investigate how temporal and spatial nest origin influence initial hatchling size and growth potential. Seasonal environmental fluctuations and maternal resource allocation could result in differential hatchling size and development. Hatchlings from ten sites from North Carolina to...
Show moreTo improve our understanding of loggerhead life history, particularly factors affecting the duration of each age class and survivorship, detailed growth data must be interpreted. The purpose of this study was to investigate how temporal and spatial nest origin influence initial hatchling size and growth potential. Seasonal environmental fluctuations and maternal resource allocation could result in differential hatchling size and development. Hatchlings from ten sites from North Carolina to Florida representing 2 subpopulations were sampled during 3 phases of the season. The largest (WT, SCL and SCW) hatchlings came from the northernmost site with initial size decreasing as latitude decreased. Turtles deposited during the earliest phase of the nesting season grew faster than those from later phases of the season. Differences in initial size and growth potential could influence early stage survivorship as a function of size-based predation, and may imply the need for separate consideration when constructing population models.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13070
- Subject Headings
- Loggerhead turtle--Growth, Sea turtles
- Format
- Document (PDF)
- Title
- Home Range and Activity Patterns in a South Florida Population of the Tortoise Gopherus polyphemus on Savannas Preserve State Park.
- Creator
- Davis, Jennifer L., Wyneken, Jeanette, Florida Atlantic University
- Abstract/Description
-
The Gopher Tortoise (Gopherus polyphemus) lives in upland habitats throughout its life. Recent rapid urbanization of coastal Florida is resulting in large scale habitat fragmentation that negatively affects this and other upland species. Losses of upland habitats result in regulatory actions that include mitigation programs and animal relocations which currently occur in the absence of understanding region-specific behavior and habitat needs. Gopher Tortoise populations are similar to one...
Show moreThe Gopher Tortoise (Gopherus polyphemus) lives in upland habitats throughout its life. Recent rapid urbanization of coastal Florida is resulting in large scale habitat fragmentation that negatively affects this and other upland species. Losses of upland habitats result in regulatory actions that include mitigation programs and animal relocations which currently occur in the absence of understanding region-specific behavior and habitat needs. Gopher Tortoise populations are similar to one another in that males have larger home ranges than females, males defend burrows and mates during the breeding season, all have a high degree of home range overlap, and forage on similar vegetation types. This study shows that Southeastern Florida Gopher Tortoises differ from those elsewhere in that they maintain relatively small home ranges, forage throughout the year, engage in social interactions yearround, and have a bimodal (late winter-spring and late summer-fall) breeding season. My study identifies differences in activity, behavior, and home ranges in a South Florida population that may refine management strategies that include reconsideration of restocking Northern populations with individuals from South Florida.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00000739
- Subject Headings
- Gopher tortoise--Habitat--Florida, Wildlife management--Florida, Environmental impact analysis--Florida
- Format
- Document (PDF)
- Title
- Spatial, temporal, and dietary overlap of leatherback sea turtles (Dermochelys coriacea) and ocean sunfishes (family Molidae).
- Creator
- Desjardin, Nicole A., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
Investigation of the spatio-temporal movements of leatherback sea turtles (Dermochelys coriacea) and ocean sunfishes (family Molidae), as well as analyses of their prey, support the hypothesis that they may occupy similar ecological niches. This study examined the spatial and temporal occurrences of sunfishes (Mola mola and Masturus lanceolatus) and leatherbacks in the western Atlantic Ocean and assessed dietary overlap. Analyses of leatherback and sunfish distributions, estimated from aerial...
Show moreInvestigation of the spatio-temporal movements of leatherback sea turtles (Dermochelys coriacea) and ocean sunfishes (family Molidae), as well as analyses of their prey, support the hypothesis that they may occupy similar ecological niches. This study examined the spatial and temporal occurrences of sunfishes (Mola mola and Masturus lanceolatus) and leatherbacks in the western Atlantic Ocean and assessed dietary overlap. Analyses of leatherback and sunfish distributions, estimated from aerial surveys, showed greater spatial and temporal overlap along the Northeast coast of North America than in the Gulf of Mexico. Both species co-occur more often during warmer months. Pelagic longline fisheries bycatch data and aerial survey data revealed slightly different trends in spatio-temporal distributions. Nematocysts found within gastrointestinal tract contents of stranded animals indicate that they may feed on similar prey, including cnidarians in the classes Scyphozoa, Hydrozoa, and Cubozoa.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13225
- Subject Headings
- Freshwater fishes--Atlantic Coast (U S )--Geographical distribution, Sea turtles--Atlantic Coast (U S )--Geographical distribution, Animal behavior
- Format
- Document (PDF)
- Title
- The Effect of Vegetation (Ipomoea pes-caprae) on Leatherback (Dermochelys coriacea) Nest Productivity.
- Creator
- Conrad, Jeremy R., Wyneken, Jeanette, Florida Atlantic University
- Abstract/Description
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From 2004 - 2007, the beach at Sandy Point National Wildlife Refuge (St. Croix, USVI) experienced low summer erosion, which allowed native pioneer vegetation to spread seaward and invade leatherback-nesting areas. The encroachment of vegetation reduced nest survival. Here I describe the results of an experimental assessment of vegetation control methods and of the effects of native vegetation on leatherback hatching and emergence success. I tested four treatments: (i) naturally vegetated, (ii...
Show moreFrom 2004 - 2007, the beach at Sandy Point National Wildlife Refuge (St. Croix, USVI) experienced low summer erosion, which allowed native pioneer vegetation to spread seaward and invade leatherback-nesting areas. The encroachment of vegetation reduced nest survival. Here I describe the results of an experimental assessment of vegetation control methods and of the effects of native vegetation on leatherback hatching and emergence success. I tested four treatments: (i) naturally vegetated, (ii) herbicide treated vegetation, (iii) mechanically removed above ground vegetation, and (iv) non-vegetated (control) plots. Nests were relocated into each of the plot types then left to incubate naturally. Hatching and emergence success was reduced when vegetation was present. Vegetation was not adequately controlled by any of the methods tested. The results identify future research needs for the development of appropriate management to control the native vegetation and enhance leatherback nest productivity.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00000736
- Subject Headings
- Vegetation dynamics, Wildlife habitat improvement, Sandy Point National Wildlife Refuge (United States Virgin Islands), Leatherback turtle--Habitat--Conservation
- Format
- Document (PDF)
- Title
- Maternal Health Status Correlates with Nest Success of Leatherback Sea Turtles (Dermochelys coriacea) from Florida.
- Creator
- Perrault, Justin R., Miller, Debra L., Eads, Erica, Johnson, Chris, Merrill, Anita, Thompson, Larry J., Wyneken, Jeanette, Reina, Richard
- Abstract/Description
-
Of the seven sea turtle species, the critically endangered leatherback sea turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60–70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this...
Show moreOf the seven sea turtle species, the critically endangered leatherback sea turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60–70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in leatherback sea turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian leatherbacks were low during the study period (2007–2008 nesting seasons), a trend common in most nesting leatherback populations (average global hatching success =~50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol, creatinine, and phosphorus. Our results suggest that in leatherbacks, physiological parameters correlate with hatching success and emergence success of their nests. We conclude that long-term and comparative studies are needed to determine if certain individuals produce nests with lower hatching success and emergence success than others, and if those individuals with evidence of chronic suboptimal health have lower reproductive success.
Show less - Date Issued
- 2012-02-16
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000084
- Format
- Citation
- Title
- Leatherbacks Swimming In Silico: Modeling and Verifying Their Momentum and Heat Balance Using Computational Fluid Dynamics.
- Creator
- Dudley, Peter N., Bonazza, Riccardo, Jones, T. Todd, Wyneken, Jeanette, Porter, Warren P., Munderloh, Ulrike G.
- Abstract/Description
-
As global temperatures increase throughout the coming decades, species ranges will shift. New combinations of abiotic conditions will make predicting these range shifts difficult. Biophysical mechanistic niche modeling places bounds on an animal’s niche through analyzing the animal’s physical interactions with the environment. Biophysical mechanistic niche modeling is flexible enough to accommodate these new combinations of abiotic conditions. However, this approach is difficult to implement...
Show moreAs global temperatures increase throughout the coming decades, species ranges will shift. New combinations of abiotic conditions will make predicting these range shifts difficult. Biophysical mechanistic niche modeling places bounds on an animal’s niche through analyzing the animal’s physical interactions with the environment. Biophysical mechanistic niche modeling is flexible enough to accommodate these new combinations of abiotic conditions. However, this approach is difficult to implement for aquatic species because of complex interactions among thrust, metabolic rate and heat transfer. We use contemporary computational fluid dynamic techniques to overcome these difficulties. We model the complex 3D motion of a swimming neonate and juvenile leatherback sea turtle to find power and heat transfer rates during the stroke. We combine the results from these simulations and a numerical model to accurately predict the core temperature of a swimming leatherback. These results are the first steps in developing a highly accurate mechanistic niche model, which can assists paleontologist in understanding biogeographic shifts as well as aid contemporary species managers about potential range shifts over the coming decades.
Show less - Date Issued
- 2014-10-29
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000060
- Format
- Citation
- Title
- Predicting leatherback sea turtle sex ratios using spatial interpolation of nesting beach temperatures.
- Creator
- Weston, Emily G., Wyneken, Jeanette, Charles E. Schmidt College of Science, Department of Biological Sciences
- 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.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004071
- Subject Headings
- 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
- Format
- Document (PDF)
- Title
- Feeding behavior of loggerhead and leatherback sea turtles:a study to better understand longline bycatch.
- Creator
- Warraich, Natasha, Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Two species of sea turtle, loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea) are caught frequently as bycatch in longline fisheries. These fisheries use hooks baited with fish or squid. Yet, leatherbacks feed on gelatinous prey while loggerheads are carnivores. I investigated the responses of these two species to bait odors in controlled laboratory experiments to better understand their feeding behavior and why they interact with longlines. Both species initiated feeding...
Show moreTwo species of sea turtle, loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea) are caught frequently as bycatch in longline fisheries. These fisheries use hooks baited with fish or squid. Yet, leatherbacks feed on gelatinous prey while loggerheads are carnivores. I investigated the responses of these two species to bait odors in controlled laboratory experiments to better understand their feeding behavior and why they interact with longlines. Both species initiated feeding behavior in the presence of squid bait odors and just C. caretta showed feeding behavior with sardine odors; neither responded to mackerel odors. The turtles are hooked differently on longlines. Loggerheads are usually hooked in the mouth while leatherbacks are usually hooked in the shoulder or flippers. Comparisons of prey attack behavior and accuracy in apprehending a stimulus in the presence of waterborne food odors identified speciesspecific differences that may predispose the turtles to particular kinds of hooking.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004171, http://purl.flvc.org/fau/fd/FA00004171
- Subject Headings
- Bycatches (Fisheries) -- Prevention, Longlining (Fisheries) -- Bycatches -- Prevention, Longlining (Fisheries) -- Environmental aspects, Sea turtles -- Effect of fishing on, Sea turtles -- Habitat -- Conservation, Sea turtles -- Mortality, Wildlife conservation
- Format
- Document (PDF)
- Title
- Identifying mating systems of imperiled marine turtles nesting in southern Florida through exclusion analysis to estimate the breeding sex ratio.
- Creator
- Lasala, Jacob A., Wyneken, Jeanette, Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
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.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013161
- Subject Headings
- Sea turtles--Florida, Mating behavior, Sex ratio
- Format
- Document (PDF)
- Title
- UNDERSTANDING THE PHENOTYPE: A STUDY ON HOW THE INCUBATION ENVIRONMENT INFLUENCES EMBRYO GROWTH, SEX, AND SEX RATIOS IN TURTLES WITH TEMPERATURE DEPENDENT SEX DETERMINATION.
- Creator
- Tezak, Boris M., Wyneken, Jeanette, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Currently, one of the most critical research priorities in wildlife science is to understand, describe, and predict how the unprecedented rate of climate change will impact organisms and ecosystems. This is particularly essential for thermally sensitive organisms that are already imperiled, such as turtles. For all known turtle species, the nest incubation environment plays a critical role in many developmental processes which can directly influence a number of phenotypic traits, such as body...
Show moreCurrently, one of the most critical research priorities in wildlife science is to understand, describe, and predict how the unprecedented rate of climate change will impact organisms and ecosystems. This is particularly essential for thermally sensitive organisms that are already imperiled, such as turtles. For all known turtle species, the nest incubation environment plays a critical role in many developmental processes which can directly influence a number of phenotypic traits, such as body size, mass, locomotor performance, behavior and even sex. Most chelonians (and all extant marine turtles) possess a mechanism known as temperature dependent sex determination (TSD), whereby gonads differentiate into ovaries or testes depending on the incubation temperature of the eggs during a critical period of embryonic development. The rapid rate of climate change highlights the need for a clear understanding of how potential changes in the nest environment will affect turtle development and hatchling phenotype. However, it is poorly understood how different environmental factors interact with the embryo’s own genetic program to produce a specific phenotype. My thesis aims to (i) provide a better understanding of the complex relationship between the developing embryo and the nest environment and its effect on hatchling phenotype, and (ii) offer a solution to the difficulties associated with identifying primary sex ratios in turtle species with TSD.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013421
- Subject Headings
- Phenotype, Temperature-dependent sex determination, Turtles--Growth
- Format
- Document (PDF)
- Title
- THE IMPACT OF ENVIRONMENTAL FACTORS ON LOGGERHEAD SEA TURTLE (CARETTA CARETTA) HATCHLING BIOLOGY.
- Creator
- Lolavar, Alexandra A., Wyneken, Jeanette, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The eggs of all sea turtle species develop in underground nests on oceanic nesting beaches. Eggs are unattended and their incubation conditions are subject to effects of the environment. Nest temperature influences various aspects of hatchling biology, including sex determination. Past studies identified that sea turtle embryos have a warm female cool male response pattern and rainfall has been thought to cool nest temperature. The effects of rainfall or periods of drought were often inferred...
Show moreThe eggs of all sea turtle species develop in underground nests on oceanic nesting beaches. Eggs are unattended and their incubation conditions are subject to effects of the environment. Nest temperature influences various aspects of hatchling biology, including sex determination. Past studies identified that sea turtle embryos have a warm female cool male response pattern and rainfall has been thought to cool nest temperature. The effects of rainfall or periods of drought were often inferred but not verified. Using laboratory and field studies, I examined how changes in environmental factors during incubation, particularly sand moisture, can affect nest conditions and hatchling biology. I derived temperature-sex ratio response curves for eggs incubated at different moisture levels to determine the effect of moisture on how embryos respond to temperature. I also studied how increasing moisture levels in relocated nests through daily watering influence nest conditions and discuss if this method is an effective mitigation strategy for the detrimental effects of increasing temperatures on embryo survival and sex ratios. I investigated how environmental factors, nest conditions, and hatchling biology can differ among sites on a nesting beach. Extreme moisture conditions, both low and high, result in a narrower transition between one sex ratio bias to another. I demonstrated that watering nests decreases nest temperatures and increases hatching success but watering has a minimal impact on sex ratios. Ambient beach conditions vary slightly in air temperature, rainfall, solar radiation, and humidity, depending on beach location. Nest conditions such as nest temperature and moisture also differ, but hatching success and sex ratios do not vary among different sites on the same nesting beach in Boca Raton, Florida. Ultimately, these studies together help identify and demonstrate how these environmental factors and drivers can affect the nest environment during incubation. Further developing our understanding of environmental factors, particularly nest moisture, and their variability will provide better predictions of future climate change effects and perhaps create more effective mitigation strategies.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013390
- Subject Headings
- Loggerhead turtle, Sea turtles--Nests, Environment, Eggs--Hatchability, Eggs--Incubation, Moisture
- Format
- Document (PDF)
- Title
- Spatial and temporal distributions of sea turtles within the Florida current and surrounding waters.
- Creator
- Bovery, Caitlin M., Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Assessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to their migratory nature and use of large current systems. Concentrations of animals can shift because turtles undergo large-scale migrations and habitat shifts seasonally as well as a function of lifestage. Surface counts of marine turtles in waters off Florida’s east coast were made in and adjacent to the Florida Current using standard aerial surveys....
Show moreAssessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to their migratory nature and use of large current systems. Concentrations of animals can shift because turtles undergo large-scale migrations and habitat shifts seasonally as well as a function of lifestage. Surface counts of marine turtles in waters off Florida’s east coast were made in and adjacent to the Florida Current using standard aerial surveys. While it is understood that marine turtles use waters off the eastern coast of Florida, here we document the magnitude of the shift in turtle presence each season throughout a two year study and identify habitat characteristics where turtles occur most frequently. Our assessment of marine turtles in the waters off southeast Florida provide valuable metrics describing the in-water biology of sea turtles in this area to inform future management strategies of these endangered species.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004083, http://purl.flvc.org/fau/fd/FA00004083
- Subject Headings
- Sea turtles -- Atlantic Coast (U.S.) -- Florida -- Distribution, Sea turtles -- Atlantic Coast (U.S.) -- Florida -- Geographical distribution
- Format
- Document (PDF)
- Title
- Developmental Morphology of Flippers in Sea Turtles and Penguins.
- Creator
- Kwong, Grace W., Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
There are no modem anatomical studies of flipper development or particularly any examining limb formation across distantly related taxa converging on similar flipper morphology. This study compares and contrasts the development of flippers in sea turtle (Caretta caretta) and penguin (Spheniscus demersus , Eudyptula minor) embryos. Embryos were fixed, cleared and stained for cartilage anlagen, and prepared as whole mounts. Skeletal elements forming the flipper and changes in their growth rates...
Show moreThere are no modem anatomical studies of flipper development or particularly any examining limb formation across distantly related taxa converging on similar flipper morphology. This study compares and contrasts the development of flippers in sea turtle (Caretta caretta) and penguin (Spheniscus demersus , Eudyptula minor) embryos. Embryos were fixed, cleared and stained for cartilage anlagen, and prepared as whole mounts. Skeletal elements forming the flipper and changes in their growth rates were described across developmental stages. Results suggest skeletal elements contribute differently to sea turtle and penguin flipper blades and there are significant differences in bone shape and growth patterns. Greater proportional increases in lengths and areas were found in sea turtles elements compared to penguins. Sea turtles appear to depend on a pathway resulting in elongation of distal elements to build a flipper, whereas penguin limbs undergo flattening and expansion of fewer elements to meet a similar structural goal.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00000784
- Subject Headings
- Sea turtles--Physiology, Sea turtles--Morphology, Penguins--Morphology, Animal locomotion, Marine ecology
- Format
- Document (PDF)
- Title
- Measuring Nest-to-Surf Mortality of Florida’s East and West Coast Loggerhead Sea Turtle (Caretta caretta) Hatchlings.
- Creator
- Villegas Vindiola, Brianna, Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Sea turtle hatchlings emerge from their nest and quickly crawl to the surf. During the crawl, hatchlings may encounter threats, biotic and abiotic, which can affect their ability to successfully reach the surf. The impact of these threats on hatchling survival during that crawl is largely undocumented. Current methods used to estimate cohort recruitment rely heavily on nest inventory data. This method, however, does not account for post-emergent hatchling mortality that occurs during the...
Show moreSea turtle hatchlings emerge from their nest and quickly crawl to the surf. During the crawl, hatchlings may encounter threats, biotic and abiotic, which can affect their ability to successfully reach the surf. The impact of these threats on hatchling survival during that crawl is largely undocumented. Current methods used to estimate cohort recruitment rely heavily on nest inventory data. This method, however, does not account for post-emergent hatchling mortality that occurs during the crawl. During the 2017-2018 nesting seasons, I quantified the fates of 1,379 loggerhead (Caretta caretta) hatchlings from 26 nest emergences during their crawl from the nest to the surf on the east and west coasts of Florida. I documented hatchling fates at 5 Florida nesting beaches: Wabasso, Boca Raton, Keewaydin Island, Naples, and Anna Maria Island. Overall, 6.5% of all emergent hatchlings died during the crawl from the nests to the surf. Ghost crabs, night herons, foxes, and coyotes killed hatchlings and photopollution and barriers on the beach (both abiotic threats) caused hatchling mortality. Anthropogenic (abiotic) threats accounted for more mortality than did predators. In order to assess how beach urbanization impacts hatchling mortality, I categorized each study site as urban (Wabasso and Naples), intermediate (Anna Maria Island and Boca Raton), or natural (Keewaydin Island) based on the relative levels of shoreline development and human activity at each beach. Sites with intermediate levels of urbanization accounted for greater levels of hatchling mortality than at other beaches due to the absolutely larger numbers of hatchlings lost to a disorientation event and to a beach barrier. Given the small numbers of emergences, at all sites, only a small proportion of the hatchlings mortalities (e.g., between 3 and 12 percent), site type could not be rigorously used as a discriminator. My results provide a better understanding of how specific environmental threats contribute to hatchling mortality. While nest-to-surf mortality is relatively low, its cumulative costs add up to several hundreds of thousands of hatchlings. Armed with this information, nesting beach managers can assess risks and focus their efforts to implement the most effective management practices to minimize losses of this imperiled species.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013277
- Subject Headings
- Loggerhead turtle--Florida, Caretta caretta, Sea turtles--Nests, Sea turtles--Mortality
- Format
- Document (PDF)
- Title
- Nest-to-surf mortality of loggerhead (Caretta caretta) sea turtle hatchlings on Florida’s east coast in 2016.
- Creator
- Erb, Victoria, Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Worldwide, sea turtles are especially vulnerable immediately after emerging from nests. Many monitoring programs measure hatchling production from nest inventories. These inventories rarely account for mortality occurring post-emergence, leaving an incomplete estimate of hatchling production. This study addresses the nest-to-surf data gap for Florida’s east coast nesting assemblages of loggerhead sea turtles (Caretta caretta). Five locations were surveyed during the 2016 nesting season by...
Show moreWorldwide, sea turtles are especially vulnerable immediately after emerging from nests. Many monitoring programs measure hatchling production from nest inventories. These inventories rarely account for mortality occurring post-emergence, leaving an incomplete estimate of hatchling production. This study addresses the nest-to-surf data gap for Florida’s east coast nesting assemblages of loggerhead sea turtles (Caretta caretta). Five locations were surveyed during the 2016 nesting season by using infrared time-lapse imagery, night vision optics, and track maps. Over all beaches, 7.6% of the observed hatchlings did not survive to reach the water. Mortality sources varied by location. Observed predators included: foxes, bobcats, yellow-crowned night herons, ghost crabs, and gulls. Hatchling disorientation and misorientation occurred more frequently in urban areas than natural areas. Factors including number of hatchlings emerging, nest-to-surf distance, and urbanization may help managers estimate nest-to-surf mortality. This study will improve life history models that serve as foundations of conservation management.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004934, http://purl.flvc.org/fau/fd/FA00004934
- Subject Headings
- Sea turtles--Mortality--Florida., Loggerhead turtle--Mortality., Predation (Biology), Sea turtles--Orientation., Animal navigation., Fire ants--Venom--Physiological effect.
- Format
- Document (PDF)
- Title
- Gopher tortoise habitat use and spatial distribution in a southeastern Florida population.
- Creator
- King, E. H., Florida Atlantic University, Wyneken, Jeanette, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Gopher tortoise ecology is poorly understood in the rapidly developing, urbanized southeastern end of its range. This study reports on a population at Florida Atlantic University in Boca Raton, Florida. Burrow surveys were conducted from May to July 2003 and May to August 2004. Burrows were marked and mapped as was vegetative cover. Burrow locations were tested against vegetative cover height and soil types. Burrow locations did not differ among soil types. The densest concentrations of...
Show moreGopher tortoise ecology is poorly understood in the rapidly developing, urbanized southeastern end of its range. This study reports on a population at Florida Atlantic University in Boca Raton, Florida. Burrow surveys were conducted from May to July 2003 and May to August 2004. Burrows were marked and mapped as was vegetative cover. Burrow locations were tested against vegetative cover height and soil types. Burrow locations did not differ among soil types. The densest concentrations of burrows were located in areas of low, patchy vegetative cover. This is consistent with known gopher tortoise habitat preferences elsewhere in their range. Gopher tortoises on this site appeared to be acclimated to anthropogenic disturbance.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13272
- Subject Headings
- Ecology, Gopher tortoise--Geographical distribution, Habitat (Ecology)--Florida, Zoogeography
- Format
- Document (PDF)
- Title
- NESTING AND IN-WATER HABITAT-USE OF LOGGERHEAD SEA TURTLES (CARETTA CARETTA) AT A GLOBALLY IMPORTANT ROOKERY IN SOUTHEAST FLORIDA, USA.
- Creator
- Hirsch, Sarah, Wyneken, Jeanette, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Despite decades of conservation efforts, population recovery remains elusive for the loggerhead sea turtles (Caretta caretta) nesting in Florida, the largest aggregation globally. Limited studies exist regarding reproductive strategies and in-water habitat use of loggerheads in southeastern Florida. I used satellite telemetry to track the movements of 17 nesting loggerheads on Juno and Jupiter Beaches during the 2020 and 2021 nesting seasons. The majority of females displayed high nest-site...
Show moreDespite decades of conservation efforts, population recovery remains elusive for the loggerhead sea turtles (Caretta caretta) nesting in Florida, the largest aggregation globally. Limited studies exist regarding reproductive strategies and in-water habitat use of loggerheads in southeastern Florida. I used satellite telemetry to track the movements of 17 nesting loggerheads on Juno and Jupiter Beaches during the 2020 and 2021 nesting seasons. The majority of females displayed high nest-site fidelity. Inter-nesting intervals ranged from 10–19 days and were negatively correlated with water temperatures. Core inter-nesting areas ranged from 3.7–805.8 km2 and were located a mean 1.6 km from land. Mean clutch frequency was 5.9 nests/female, the highest reported for any loggerhead population worldwide. These findings suggest the number of females in the southeastern Florida population may be over-estimated due to an underestimated clutch frequency. Protective measures should target high-use coastal areas to maximize conservation benefits.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013882
- Subject Headings
- Loggerhead sea turtles, Loggerhead turtle--Florida, Turtles--Conservation, Biotelemetry
- Format
- Document (PDF)
