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Pages
- Title
- Determining the sensitive period for magnetic imprinting in loggerhead turtles.
- Creator
- Pate, Jessica Hope, Salmon, Michael, Franquiz, Auriel, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361335
- Subject Headings
- Loggerhead turtle, Geomagnetism, Imprinting
- 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
- 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 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
- The effect of filtered roadway lighting on nesting by loggerhead sea turtles (Caretta caretta L.).
- Creator
- Pennell, Jeffrey P., Florida Atlantic University, Salmon, Michael, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The purpose of this study was to determine if filtered street lighting affected the nesting behavior of loggerhead sea turtles ( Caretta caretta L.). My study site was a nesting beach at Carlin Park, Jupiter, Florida. During the 1999 nesting season, portions of the beach were either kept dark or were illuminated by four 70 W high-pressure sodium (HPS) streetlights, each housed in a cut-off fixture covered by an acrylic (model #2422) filter. These filters excluded all light wavelengths below...
Show moreThe purpose of this study was to determine if filtered street lighting affected the nesting behavior of loggerhead sea turtles ( Caretta caretta L.). My study site was a nesting beach at Carlin Park, Jupiter, Florida. During the 1999 nesting season, portions of the beach were either kept dark or were illuminated by four 70 W high-pressure sodium (HPS) streetlights, each housed in a cut-off fixture covered by an acrylic (model #2422) filter. These filters excluded all light wavelengths below 540 nm. The excluded wavelengths repel nesting females. Daily counts of nesting and non-nesting crawls were made. Data from the 1999 nesting season were compared to historical records of nesting at the site between 1990 and 1998. I found no evidence that filtered lights affected nesting densities, or the ratio of successful to unsuccessful crawls. These results suggest that at Carlin Park, the nesting behavior of loggerhead females is unaffected by exposure of the beach to filtered street lighting.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12720
- Subject Headings
- Loggerhead turtle, Sea turtles--Nests
- Format
- Document (PDF)
- Title
- Effects on beach renourishment on the survival of loggerhead sea turtles.
- Creator
- Broadwell, Ann L., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
The fate of loggerhead (Caretta caretta, L.) clutches at four physically different beaches, including a renourished site, was investigated in the Boca Raton area. I compared the four sites with regard to their thermal environment, moisture content, sand grain size, and pore spacing at depths of a typical nest. Significantly more sea turtle hatchlings emerged from nests deposited on the renourished beach than at the other sites. At the renourished beach moisture content and pore spacing were...
Show moreThe fate of loggerhead (Caretta caretta, L.) clutches at four physically different beaches, including a renourished site, was investigated in the Boca Raton area. I compared the four sites with regard to their thermal environment, moisture content, sand grain size, and pore spacing at depths of a typical nest. Significantly more sea turtle hatchlings emerged from nests deposited on the renourished beach than at the other sites. At the renourished beach moisture content and pore spacing were highest. Pore spacing and moisture content correlated negatively with the number of hatchlings which died in the nest, and correlated positively with emergence success. At the natural beach, hatchling weight was lowest and straight-line carapace length (SLC) was shortest. I conclude that at the renourished beach, conditions favored hatchling production. However, that may not be the case in all instances of renourishment, as effects probably vary with the nature of the sands used to replenish the beach.
Show less - Date Issued
- 1991
- PURL
- http://purl.flvc.org/fcla/dt/14749
- Subject Headings
- Loggerhead turtle--Reproduction, Loggerhead turtle--Florida
- Format
- Document (PDF)
- Title
- Visual wavelength discrimination by the loggerhead turtle, Caretta caretta.
- Creator
- Young, Morgan, Salmon, Michael, Forward, Richard B., Jr., Graduate College
- Date Issued
- 2011-04-08
- PURL
- http://purl.flvc.org/fcla/dt/3164729
- Subject Headings
- Loggerhead turtle, Spectral sensitivity, Phototaxis
- Format
- Document (PDF)
- Title
- IMPACT OF SARGASSUM ACCUMULATIONS ON LOGGERHEAD HATCHLING RECRUITMENT TO NEARSHORE WATER ON A RAKED URBAN NESTING BEACH IN FLORIDA.
- Creator
- Schiariti, Joshua P., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Hatchling loggerhead turtles emerge from subsurface nests on the beach at night, crawl down the beach and enter the sea. Recently, increases in a floating algae (Sargassum) has been reported in the mid-Atlantic and the Caribbean, resulting in large algal wrack on Florida beaches. The purpose of my study was to determine if these accumulations acted as a barrier, preventing hatchlings from completing their crawl to the sea. To address this issue I recorded seasonal changes in Sargassum density...
Show moreHatchling loggerhead turtles emerge from subsurface nests on the beach at night, crawl down the beach and enter the sea. Recently, increases in a floating algae (Sargassum) has been reported in the mid-Atlantic and the Caribbean, resulting in large algal wrack on Florida beaches. The purpose of my study was to determine if these accumulations acted as a barrier, preventing hatchlings from completing their crawl to the sea. To address this issue I recorded seasonal changes in Sargassum density and directly observed when, and under what circumstances, hatchlings could cross the wrack. There was a significant overlap between when Sargassum accumulation peaked and when the turtles emerged, with the result that hatchling recruitment was significantly reduced (by~22%) during the 2020 nesting season. I conclude that algal accumulations represent a significant threat that may impede the recovery of loggerhead populations, that are currently threatened or endangered worldwide.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013806
- Subject Headings
- Loggerhead turtle, Sargassum, Conservation biology
- 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
-
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)
- Title
- New paternity analyses may confound current population models for loggerhead sea turtles (caretta caretta).
- Creator
- Lasala, Jacob, Harrison, J. S., Williams, K., Frick, M, Rostal, D. C., Wyneken, Jeanette, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361944
- Subject Headings
- Loggerhead turtle, Caretta caretta, Polyandry, Population Dynamics
- Format
- Document (PDF)
- Title
- Assessing the Effects of Incubation Temperature on the Cognitive Ability of Hatchling Loggerhead (Caretta caretta) Sea Turtles.
- Creator
- Serra, Ivana, Milton, Sarah, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Under the expected warmer temperatures due to climate change, sea turtle embryos may be subjected to thermal conditions detrimental to nest success and hatchling quality; one trait which may be negatively affected is cognitive ability. In this study, loggerhead sea turtle eggs were acquired from Boca Raton, FL and lab incubated under two female-producing temperatures: an “optimal” temperature of 31°C and a sublethal temperature of 33°C. Cognitive ability of post-hatchlings, assessed via...
Show moreUnder the expected warmer temperatures due to climate change, sea turtle embryos may be subjected to thermal conditions detrimental to nest success and hatchling quality; one trait which may be negatively affected is cognitive ability. In this study, loggerhead sea turtle eggs were acquired from Boca Raton, FL and lab incubated under two female-producing temperatures: an “optimal” temperature of 31°C and a sublethal temperature of 33°C. Cognitive ability of post-hatchlings, assessed via associative learning and reversal was investigated using a y-maze. The sublethal temperature decreased incubation duration, hatch success, hatchling growth rates and produced smaller hatchlings with significantly more scute anomalies. Hot hatchlings performed worse on the reversal, taking longer to train, and thus hint at an effect of incubation temperature on cognitive flexibility in loggerhead turtles. With temperatures rising on beaches in South Florida, this study provides evidence of further potential threats to hatchling quality and potentially even survival.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013559
- Subject Headings
- Loggerhead turtle, Eggs--Incubation, Temperature, Cognition
- Format
- Document (PDF)
- Title
- WHAT MECHANISMS UNDERLIE SYNCHRONOUS HATCHING IN LOGGERHEAD TURTLE NESTS?.
- Creator
- Field, Angela, Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The goal of this study was to determine if hatching synchrony occurs in loggerhead sea turtle nests and if it does, what mechanism(s) promote that synchrony. Synchrony may occur because oviposition takes place during a single evening, and because incubation temperatures within the nest show relatively little variation; thus, rates of embryonic development among the eggs are similar ("temporal synchrony hypothesis"). Alternatively, synchrony might be enhanced through embryo-to-embryo...
Show moreThe goal of this study was to determine if hatching synchrony occurs in loggerhead sea turtle nests and if it does, what mechanism(s) promote that synchrony. Synchrony may occur because oviposition takes place during a single evening, and because incubation temperatures within the nest show relatively little variation; thus, rates of embryonic development among the eggs are similar ("temporal synchrony hypothesis"). Alternatively, synchrony might be enhanced through embryo-to-embryo communication that stimulates and synchronizes development ("coordinated hatching hypothesis"). Experiments were designed to distinguish between these two hypotheses. I found that if only a few embryos survive, temporal synchrony occurs. However, if many embryos survive, the duration of incubation and hatching shortens, presumably because embryonic movements inside soft-shelled eggs are detected by and transmitted between eggs and stimulate development, expediting hatching synchrony.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013505
- Subject Headings
- Loggerhead turtle, Nests, Eggs—Incubation, Synchrony
- 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
- Calcium requirement and growth in the hatchling loggerhead sea turtle (Caretta caretta L.).
- Creator
- Alexander, Jeanne Louise., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
The calcium requirement in captive-raised hatchling loggerhead sea turtles (Caretta caretta) was investigated. Comparisons were made among turtles on 6 experimental diets and between captive and wild turtles. Diets consisted of trout chow diets containing 1%, 2%, 3%, or 4% calcium and 1.65% phosphorous, AquaMax 500RTM (2% Ca), and shrimp. Feeding trials lasted 28 days and changes in body size and bone density were measured. The calcium and phosphorous content of foods eaten by post-hatchlings...
Show moreThe calcium requirement in captive-raised hatchling loggerhead sea turtles (Caretta caretta) was investigated. Comparisons were made among turtles on 6 experimental diets and between captive and wild turtles. Diets consisted of trout chow diets containing 1%, 2%, 3%, or 4% calcium and 1.65% phosphorous, AquaMax 500RTM (2% Ca), and shrimp. Feeding trials lasted 28 days and changes in body size and bone density were measured. The calcium and phosphorous content of foods eaten by post-hatchlings in the sargassum were compared with captive diets. Results showed that shrimp was high in protein and low in calcium, with nearly twice as much P as Ca. The growth trials showed that turtles fed shrimp versus all other diets grew larger. There was no difference in total bone density of any treatment over the study. No signs of hypocalcemia were present, therefore, no lower limit for calcium requirement was determined in this study.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12708
- Subject Headings
- Loggerhead turtle, Sea turtles--Nutrition, Calcium in animal nutrition
- Format
- Document (PDF)
- Title
- Orientation of hatchling loggerhead sea turtles in response to the inclination of the magnetic field.
- Creator
- Light, Phillip Richard, Florida Atlantic University, Salmon, Michael, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Recent studies have shown that hatchling loggerhead sea turtles possess the ability to orient to the earth's magnetic field. These experiments did not identify the specific component of the field used by turtles to determine direction. One of the field's most important characteristics, inclination, has been implicated as the specific property used by birds to orient. This study investigated the possibility that sea turtles use the inclination of the earth's field in a similar manner. Results...
Show moreRecent studies have shown that hatchling loggerhead sea turtles possess the ability to orient to the earth's magnetic field. These experiments did not identify the specific component of the field used by turtles to determine direction. One of the field's most important characteristics, inclination, has been implicated as the specific property used by birds to orient. This study investigated the possibility that sea turtles use the inclination of the earth's field in a similar manner. Results show that turtles determine direction with the use of an inclination compass similar to the one used by birds to orient. This study has important implications regarding the mechanisms used by animals to orient and navigate.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14787
- Subject Headings
- Loggerhead turtle, Animal orientation, Magnetic fields, Sea turtles--Migration
- Format
- Document (PDF)
- Title
- The magnetic compass of the loggerhead sea turtle (Caretta caretta L.): Can surface waves establish magnetic directional preference?.
- Creator
- Goff, Matthew Douglas, Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Hatchling loggerhead sea turtles emerge from their nests on oceanic beaches, crawl to the surf zone, and swim out to sea. How do turtles maintain oriented headings once they lose contact with land? I tested the hypothesis that by swimming into surface waves hatchlings establish an offshore heading (directional preference), and that once out to sea this heading is transferred to, and maintained by, a magnetic compass. This hypothesis was supported by laboratory and field experiments, described...
Show moreHatchling loggerhead sea turtles emerge from their nests on oceanic beaches, crawl to the surf zone, and swim out to sea. How do turtles maintain oriented headings once they lose contact with land? I tested the hypothesis that by swimming into surface waves hatchlings establish an offshore heading (directional preference), and that once out to sea this heading is transferred to, and maintained by, a magnetic compass. This hypothesis was supported by laboratory and field experiments, described herein. A directional preference can also be established by oriented crawling (from the nest to the surf zone). Thus hatchlings possess two mechanisms (crawling and swimming) for the establishment of an offshore heading. The use of these alternative mechanisms probably assures that turtles escape from shore under the broad range of conditions which they naturally encounter after emerging from their nests.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15285
- Subject Headings
- Loggerhead turtle, Sea turtles--Orientation, Animal navigation
- Format
- Document (PDF)
- Title
- The effects of beach renourishment on the nesting behavior and hatching success of the loggerhead sea turtle on Jupiter Island, Florida: A seven year study.
- Creator
- Steinitz, Mary Julie., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Jupiter Island is a barrier Island on the central East Coast of Florida whose beaches are subject to severe erosion. At intervals of several years, lost sand is replaced by the addition of sand ("renourishment") from other locations. In this study, I determined the effect of sand replacement on sea turtle nesting activity, and on the survival of nests placed on renourished and an adjacent natural beach. Renourishment caused a reduction in nesting activity by the turtles, which lasted about...
Show moreJupiter Island is a barrier Island on the central East Coast of Florida whose beaches are subject to severe erosion. At intervals of several years, lost sand is replaced by the addition of sand ("renourishment") from other locations. In this study, I determined the effect of sand replacement on sea turtle nesting activity, and on the survival of nests placed on renourished and an adjacent natural beach. Renourishment caused a reduction in nesting activity by the turtles, which lasted about two years. Thereafter, turtle nesting on renourished and control beaches was similar. There were no differences in nest survival between the two sites. Renourishment prevents the loss of beach and shoreline property, but is not necessarily beneficial to sea turtles.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15292
- Subject Headings
- Loggerhead turtle, Sea turtles--Florida--Jupiter Island, Beach nourishment
- Format
- Document (PDF)
- Title
- The effects of filtered high-pressure sodium lighting on hatchling loggerhead (Caretta caretta L.) and green turtle ( Chelonia mydas L.) hatchlings.
- Creator
- Nelson, Kristen Ann, Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Hatchling sea turtles use visual cues to orient to the water. Streetlights placed on coastal roadways can attract the turtles inland. Filters were designed to be used with coastal roadway lighting to eliminate the more harmful wavelengths of light. I tested the General Electric 2422 and NLW filters in a laboratory setting with hatchling loggerhead and green turtles. Both species of turtles were attracted to the amber filtered lighting in arena experiments. Loggerhead hatchlings were used in T...
Show moreHatchling sea turtles use visual cues to orient to the water. Streetlights placed on coastal roadways can attract the turtles inland. Filters were designed to be used with coastal roadway lighting to eliminate the more harmful wavelengths of light. I tested the General Electric 2422 and NLW filters in a laboratory setting with hatchling loggerhead and green turtles. Both species of turtles were attracted to the amber filtered lighting in arena experiments. Loggerhead hatchlings were used in T-maze experiments where they were given a choice between amber filtered and unfiltered lighting. The turtles preferred the unfiltered lighting to the filtered lighting, even when it was 100 to 1000 times dimmer. I conclude that amber filtered lighting does afford some protection to sea turtles, although it must be used in conjunction with other light management techniques to prevent the disruption of hatchling turtle orientation.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/12982
- Subject Headings
- Loggerhead turtle, Green turtle, Lighting--Environmental aspects
- Format
- Document (PDF)
- Title
- The orientation and survival of loggerhead sea turtle hatchlings (Caretta caretta L.) in the nearshore environment.
- Creator
- Glenn, Lawrence, Florida Atlantic University, Salmon, Michael, Wyneken, Jeanette
- Abstract/Description
-
Hatchling sea turtles emerge at night from underground nests, crawl to the ocean, and swim out to sea. In this study, I determined how offshore orientation and shallow-water predation rates varied under natural (sand bottom and patch reef) and modified (submerged breakwater and open-beach hatchery) ecological circumstances. Hatchling offshore orientation in the sea was normal under all conditions; there were no significant differences in either scatter or direction among groups. However,...
Show moreHatchling sea turtles emerge at night from underground nests, crawl to the ocean, and swim out to sea. In this study, I determined how offshore orientation and shallow-water predation rates varied under natural (sand bottom and patch reef) and modified (submerged breakwater and open-beach hatchery) ecological circumstances. Hatchling offshore orientation in the sea was normal under all conditions; there were no significant differences in either scatter or direction among groups. However, predators (tarpon, snapper, barracuda, jacks, and grouper) took more hatchlings as they swam over submerged reefs, and after they entered the water in front of hatcheries. Predators were concentrated at both of these sites probably because prey (small fishes and invertebrates at patch reefs and turtles entering the water where nests were concentrated in hatcheries) occur in greater abundance.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15282
- Subject Headings
- Loggerhead turtle, Sea turtles--Orientation, Animal navigation
- Format
- Document (PDF)
- Title
- Endogenous programs and the development of sea-finding orientation of loggerhead hatchlings (Caretta caretta).
- Creator
- Barrett, Christie A., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
This study's objective was to determine if the transfer of a crawling direction to a magnetic compass in loggerhead hatchling sea turtles ( Caretta caretta L.) was facilitated by how long the turtle crawled (an "endogenous timing" component). I first determined how long it took hatchlings to crawl from their nest to the ocean. Two types of experiments were then carried out. In the first, crawling time varied. In the second, both crawling time and direction varied. I found that at most beaches...
Show moreThis study's objective was to determine if the transfer of a crawling direction to a magnetic compass in loggerhead hatchling sea turtles ( Caretta caretta L.) was facilitated by how long the turtle crawled (an "endogenous timing" component). I first determined how long it took hatchlings to crawl from their nest to the ocean. Two types of experiments were then carried out. In the first, crawling time varied. In the second, both crawling time and direction varied. I found that at most beaches hatchlings crawled to the ocean in less than 5 min. My experiments showed that if crawls are too short (1 min), or too long (5 min), vector transfer is weakened compared to a 2 min crawl. I also found that a period of non-directional crawling interfered with the ability of a 2 min crawl to promote calibration. These results confirm that efficient transfer of a crawling vector, maintained by visual compass, to a swimming vector, maintained by a magnetic compass, depends upon an endogenous timing program in hatchlings. The temporal properties of that program are, in turn, apparently shaped by where their mothers place nests on the beach.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13175
- Subject Headings
- Animal orientation, Animal navigation, Sea turtles--Orientation, Loggerhead turtle
- Format
- Document (PDF)
