Current Search: Leatherback turtle (x)
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- Title
- How leatherback hatchlings recognize their prey: Sensory predispositions and behavioral responses.
- Creator
- Constantino, Maricela Alcantara., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Leatherback sea turtles (Dermochelys coriacea) feed exclusively on gelatinous prey. Hatchlings are solitary and must possess a predisposition to respond to prey. In laboratory experiments, I studied the responses of nineteen leatherback hatchlings to visual (jellyfish model and shapes: circle, square, diamond) and chemical (homogenates of three prey) stimuli presented alone or as paired (visual + chemical) treatments once daily. When presented alone visual stimuli resembling jellyfish...
Show moreLeatherback sea turtles (Dermochelys coriacea) feed exclusively on gelatinous prey. Hatchlings are solitary and must possess a predisposition to respond to prey. In laboratory experiments, I studied the responses of nineteen leatherback hatchlings to visual (jellyfish model and shapes: circle, square, diamond) and chemical (homogenates of three prey) stimuli presented alone or as paired (visual + chemical) treatments once daily. When presented alone visual stimuli resembling jellyfish outlines elicited stronger feeding responses (changes in locomotion and orientation) than those not resembling jellyfish. Chemical stimuli alone induced a rheotaxis, but responses evoked by some homogenates were stronger than responses to others. Paired stimuli evoked stronger orientation and more consistent increases in swimming (flipper stroke) rate, indicating additive effects. Results suggest that both stimuli elicit food searching behavior and when they begin to forage, hatchlings already possess predispositions to respond to an adaptive array of prey shapes and odors.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12873
- Subject Headings
- Leatherback turtle, Predation (Biology)
- Format
- Document (PDF)
- Title
- From salps to sea turtles: mercury and selenium in leatherback sea turtles (Dermochelys coriacea).
- Creator
- Perrault, Justin R., Wyneken, Jeanette, Miller, Debra L., Graduate College
- Date Issued
- 2011-04-08
- PURL
- http://purl.flvc.org/fcla/dt/3164679
- Subject Headings
- Leatherback turtle, Mercury --Toxicology, Selenium
- Format
- Document (PDF)
- Title
- Visual spectral sensitivity of loggerhead (Caretta caretta L.) and leatherback (Dermochelys coriacea L.) hatchlings: A comparative study.
- Creator
- Gocke, Judith P., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
In the ocean, lighting varies with habitat; the eye's spectral sensitivity must vary with visual ecology. Green turtles are the only sea turtle whose spectral sensitivity has been studied. Loggerheads and leatherbacks see visible light between 340 and 700 nm. However, the wavelengths detected with the greatest sensitivity by both species are those best transmitted at the specific depths where food, mates and predators are likely to be encountered. Both species have trichromatic vision, but...
Show moreIn the ocean, lighting varies with habitat; the eye's spectral sensitivity must vary with visual ecology. Green turtles are the only sea turtle whose spectral sensitivity has been studied. Loggerheads and leatherbacks see visible light between 340 and 700 nm. However, the wavelengths detected with the greatest sensitivity by both species are those best transmitted at the specific depths where food, mates and predators are likely to be encountered. Both species have trichromatic vision, but the species differ in the concentration and peak sensitivity of each visual pigment resulting in either a broadly tuned (loggerhead) or finely tuned (leatherback) spectral sensitivity. Spectral sensitivity of leatherbacks overlaps both bioluminescence of prey, and light available in clear, deep, oceanic waters.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13029
- Subject Headings
- Loggerhead turtle, Leatherback turtle, Spectral sensitivity
- Format
- Document (PDF)
- Title
- A comparative approach to understanding sea turtle hatchling metabolism during emergence.
- Creator
- Redfearn, Erin Cherish., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
Sea turtle nests were compared to determine the effects of nest depth on hatchling anaerobic metabolism in Juno Beach, Florida, USA. In situ nests of 3 species (Caretta caretta, Chelonia mydas and Dermochelys coriacea) were compared. Relocated loggerhead nests were studied under an experimental regime. Nest temperatures and oxygen concentrations were monitored. On the night of first emergence, blood samples were taken from hatchlings resting at the nest chamber bottom and sand surface, and...
Show moreSea turtle nests were compared to determine the effects of nest depth on hatchling anaerobic metabolism in Juno Beach, Florida, USA. In situ nests of 3 species (Caretta caretta, Chelonia mydas and Dermochelys coriacea) were compared. Relocated loggerhead nests were studied under an experimental regime. Nest temperatures and oxygen concentrations were monitored. On the night of first emergence, blood samples were taken from hatchlings resting at the nest chamber bottom and sand surface, and digging to the sand surface. Samples were analyzed for lactate concentrations. Blood lactate levels were high in hatchlings actively digging and low for those resting. Lactate levels differed among species and nest depths. Within in situ nests, actively digging green turtle hatchlings had the highest lactate, followed by loggerhead hatchlings and leatherbacks (lowest). Loggerhead hatchlings digging from deeper relocated nests had higher lactate than those digging from shallower depths.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/15770
- Subject Headings
- Sea turtles--Metabolism, Loggerhead turtle, Green turtle, Leatherback turtle
- Format
- Document (PDF)
- Title
- EVIDENCE FOR THE INDEPENDENT EVOLUTION OF VISUAL PERCEPTION DURING SEAFINDING BY HATCHLING LEATHERBACK SEA TURTLES (DERMOCHELYS CORIACEA).
- Creator
- Trail, Samantha E., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Hatchling marine turtles exhibit a positive phototaxis by crawling toward the lowest and brightest horizon when they emerge from nests on the beach at night, which should lead them to the ocean (“seafinding”). Previous research with cheloniid (loggerhead and green turtle) hatchlings demonstrated that the perceptual spectral sensitivities are well below the light available on the beach regardless of lunar phase. The goal of this research was to determine the perceptual spectral sensitivities...
Show moreHatchling marine turtles exhibit a positive phototaxis by crawling toward the lowest and brightest horizon when they emerge from nests on the beach at night, which should lead them to the ocean (“seafinding”). Previous research with cheloniid (loggerhead and green turtle) hatchlings demonstrated that the perceptual spectral sensitivities are well below the light available on the beach regardless of lunar phase. The goal of this research was to determine the perceptual spectral sensitivities of leatherback hatchlings, the most distantly related of all extant sea turtle species. This study revealed that, like cheloniids, leatherbacks are most sensitive to shorter wavelengths (< 500 nm). However, leatherbacks were 10 – 100x less sensitive than cheloniids at all tested wavelengths. This difference in sensitivity corresponds with increased crawl duration and circling behavior under new moon conditions when light levels are lowest and the difference in radiance between the landward and seaward direction is small.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013790
- Subject Headings
- Leatherback turtle, Dermochelys coriacea, Phototaxis, Spectral sensitivity
- Format
- Document (PDF)
- Title
- INJURY ANALYSIS OF LEATHERBACK SEA TURTLES (DERMOCHELYS CORIACEA) NESTING ON NORTHERN PALM BEACH COUNTY, FLORIDA, USA BEACHES.
- Creator
- Klingshirn, Skyler, Page-Karjian, Annie, Florida Atlantic University, Department of Marine Science and Oceanography, Charles E. Schmidt College of Science
- Abstract/Description
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The leatherback sea turtle (Dermochelys coriacea) is facing global declines; however, the Florida stock is generally increasing. Various studies have identified threats to sea turtles, but there is a need to quantify population-level threats. I used external examination and blood analyses of leatherbacks nesting on northern Palm Beach County, Florida beaches to understand the impact(s) that physical injuries have on this population. Notable injuries were present on 118 of 167 (70.7%) turtles....
Show moreThe leatherback sea turtle (Dermochelys coriacea) is facing global declines; however, the Florida stock is generally increasing. Various studies have identified threats to sea turtles, but there is a need to quantify population-level threats. I used external examination and blood analyses of leatherbacks nesting on northern Palm Beach County, Florida beaches to understand the impact(s) that physical injuries have on this population. Notable injuries were present on 118 of 167 (70.7%) turtles. Fisheries injuries were more prevalent than other anthropogenic injuries; however, there was a higher overall prevalence of natural injuries. There were no notable findings from my blood analyses. My results suggest that while natural injuries are more common than anthropogenic injuries in the nesting population of Florida leatherbacks, anthropogenic injuries are more likely to result in severe traumatic wounds. Future investigation of overlap in leatherback migratory routes and foraging grounds with various threats could further protect this species.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013743
- Subject Headings
- Dermochelys coriacea, Leatherback turtle--Florida, Injury
- Format
- Document (PDF)
- Title
- Feeding behavior of loggerhead (caretta caretta) and leatherback (dermochelys coriacea) sea turtles: a model to understand bycatch.
- Creator
- Warraich, Natasha, Wyneken, Jeanette, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361369
- Subject Headings
- Leatherback turtle, Loggerhead turtle, Feeding behavior in animals, Bycatches (Fisheries)
- Format
- Document (PDF)
- Title
- Interpreting the Pre-Nesting Foraging Ecology of Florida’s Leatherback Turtles (Dermochelys coriacea).
- Creator
- Coppenrath, Christina, Baldwin, John D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The migratory behavior of North Atlantic leatherback turtles (Dermochelys coriacea) has been documented in the Wider Caribbean, but the migratory movements of leatherbacks nesting in South Florida are relatively understudied. Our knowledge of their migrations is currently limited to ten nesting females tracked from the east coast of Florida that either moved north to the Northern Atlantic or east to the coast of Western Africa. These results bring to light the need for further investigation...
Show moreThe migratory behavior of North Atlantic leatherback turtles (Dermochelys coriacea) has been documented in the Wider Caribbean, but the migratory movements of leatherbacks nesting in South Florida are relatively understudied. Our knowledge of their migrations is currently limited to ten nesting females tracked from the east coast of Florida that either moved north to the Northern Atlantic or east to the coast of Western Africa. These results bring to light the need for further investigation and larger sample sizes to identify and determine the relative importance of the different foraging areas for the leatherbacks nesting in South Florida. Here, I analyzed stable carbon (δ13C) and stable nitrogen (δ15N) values in whole blood and skin of leatherbacks nesting in South Florida between 2014 and 2017 to estimate the putative foraging origins of these nesters prior to coming to South Florida to nest. This study provides some of the first stable isotope inferences and insights into the variable pre-nesting foraging habitat locations of Florida’s leatherback population.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013014
- Subject Headings
- Leatherback turtle--Florida, Dermochelys coriacea, Foraging behavior in animals
- Format
- Document (PDF)
- Title
- Investigating maternal health and hatchling mortality in leatherback sea turtles (Dermochelys coriacea v.).
- Creator
- Perrault, Justin R., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The reproductive success of leatherback turtles (Dermochelys coriacea) is typically the lowest of the seven sea turtle species. Why this vital rate is decreased has remained unanswered for nearly a century. Recently, detailed postmortem examination of leatherback hatchlings identified muscular pathologies that suggested possible selenium deficiency. High bodily burdens of mercury compounds are associated with selenium depletion. Selenium is a necessary detoxifying nutrient that itself can be...
Show moreThe reproductive success of leatherback turtles (Dermochelys coriacea) is typically the lowest of the seven sea turtle species. Why this vital rate is decreased has remained unanswered for nearly a century. Recently, detailed postmortem examination of leatherback hatchlings identified muscular pathologies that suggested possible selenium deficiency. High bodily burdens of mercury compounds are associated with selenium depletion. Selenium is a necessary detoxifying nutrient that itself can be toxic at elevated concentrations. Mercury compounds are toxicants with no known biological function. High bodily concentrations of mercury can be detrimental to marine organismal health, reproduction and survival, both directly and indirectly through inducing selenium depletion. The goals of this dissertation are to evaluate several related hypotheses to explain low leatherback nest success. ... Because leatherbacks take in high volumes of prey, high tissue concentrations of mercury and selenium can result. This study provides the first evidence that chemical contaminants may explain low reproductive success in leatherback sea turtles.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362575
- Subject Headings
- Selenium, Physiological effect, Predation (Biology), Leatherback turtle, Mortality, Sea turtles, Mortality, Wildlife conservation
- Format
- Document (PDF)
- Title
- Behavioral Responses of Leatherback Juveniles (Dermochelys coriacea L) to Lights Used in the Longline Fishery.
- Creator
- Gless, Jodie M., Salmon, Michael, Florida Atlantic University
- Abstract/Description
-
The pelagic longline fishery is responsible for significant mortality to sea turtles as a result of foul hooking, entanglement in the lines, and internal injury after consuming the baited hook. Bait, gear and lights (used to attract the target fishes to the baits at night) are three variables that could also attract sea turtles to the lines. This study tests the role of the lights in attracting leatherback (Dermochelys coriacea) turtles and compares their behavior to the loggerhead (Caretta...
Show moreThe pelagic longline fishery is responsible for significant mortality to sea turtles as a result of foul hooking, entanglement in the lines, and internal injury after consuming the baited hook. Bait, gear and lights (used to attract the target fishes to the baits at night) are three variables that could also attract sea turtles to the lines. This study tests the role of the lights in attracting leatherback (Dermochelys coriacea) turtles and compares their behavior to the loggerhead (Caretta carelta), shown in previous studies to orient toward both lightsticks and battery powered LEDs used in the fishery. The same lights were used in experiments done on leatherbacks reared at Florida Atlantic University's Marine Laboratory. The leatherbacks were exposed to the lights at night when they were between 5 and 42 days old. The results show that leatherbacks, unlike loggerheads, either do not orient toward the lights or orient away from them at an angle that enabled the turtles to keep the light in their peripheral field cf view. Thus, the capture of leatherbacks in longlines is probably a consequence of other factors (such as attraction to the odor of the baits, or to natural prey located near the Iines) that need to be investigated through future research. The results also show that efforts to reduce the incidental capture and injury of marine turtles in longlines must be based upon a firm understanding of the similarities, as well as the differences, between turtle species.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00000763
- Subject Headings
- Longlining (Fisheries), Fishery management, Spectral sensitivity, Leatherback turtle--Research, 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
- 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
-
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)