View All Items

Title: A comparison of body proportions in juvenile sea turtles: how shape may optimize survival in a vulnerable life stage.
Creator: Pate, Jessica Hope, Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Marine turtles produce many offspring which offsets the high mortality experienced by turtles during early development. Juvenile mortality might be reduced by evolving effective behavioral as well as morphological anti-predator defenses. Body proportions of three species (Caretta caretta, Chelonia mydas, Dermochelys coriacea) of turtles were measured in the first fourteen weeks of development to examine how growth may mitigate predation by gape-limited predators. Growth was categorized as...
Show moreMarine turtles produce many offspring which offsets the high mortality experienced by turtles during early development. Juvenile mortality might be reduced by evolving effective behavioral as well as morphological anti-predator defenses. Body proportions of three species (Caretta caretta, Chelonia mydas, Dermochelys coriacea) of turtles were measured in the first fourteen weeks of development to examine how growth may mitigate predation by gape-limited predators. Growth was categorized as isometric if shape did not change during development or allometric if body shape did change. All three species showed allometric growth in carapace width; however it was less pronounced in the larger D. coriacea turtles. Allometric growth in carapace width decreased as all three species grew in size. When high predation occurs in early development, many species will favor rapid growth into a size refuge. Juvenile sea turtles may optimize their survival by growing allometrically when predation risk is the greatest.
Show less
Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004223, http://purl.flvc.org/fau/fd/FA00004223
Subject Headings: Predation (Biology), Sea turtles -- Growth, Sea turtles -- Mortality, Sea turtles -- Population viability analysis
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: 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: Impact of the Fire Ant Pesticide Hydramethylnon (AMDRO®) on Loggerhead Sea Turtle Reproductive Success and Hatchling Quality.
Creator: Smith, Heather, Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Invasive fire ants are aggressive predators of ground nesting birds and reptiles and are spreading rapidly throughout tropical and temperate climates. Fire ants have been known to prey on a variety of reptile species, including threatened loggerhead sea turtles. The granular fire ant bait AMDRO® is being used on sea turtle nesting beaches to protect nests and hatchlings from these predators, however no studies have been conducted to thoroughly assess its effect on any reptile species. In this...
Show moreInvasive fire ants are aggressive predators of ground nesting birds and reptiles and are spreading rapidly throughout tropical and temperate climates. Fire ants have been known to prey on a variety of reptile species, including threatened loggerhead sea turtles. The granular fire ant bait AMDRO® is being used on sea turtle nesting beaches to protect nests and hatchlings from these predators, however no studies have been conducted to thoroughly assess its effect on any reptile species. In this field study, I examined the impact of AMDRO® on hatching and emergence success, body condition, and orientation behavior in loggerhead sea turtles (Caretta caretta) in Juno Beach, Florida, USA. Pesticide granules were placed in a one-foot diameter circle directly above nest chambers during the final 5-10 days of incubation, which is representative of typical field applications of this pesticide on nesting beaches. Two controls were used in this study: cornmeal granules in soybean oil served as the vehicle control, and a second group of untreated control nests were left to incubate naturally, undisturbed. After a natural emergence, hatchlings were collected to calculate a body condition index (BCI). For a subset of the nests, 20 hatchlings were collected to perform orientation assays to assess the hatchlings’ ability to orient correctly toward the ocean, a visually mediated process that could be altered by visual impairments resulting from ADMRO® exposure. Three days following a mass emergence event, nests were excavated to collect hatching and emergence success data. Sand samples were collected to determine if the toxicant persisted in the environment or penetrated the egg chamber. Analyses indicated that the toxicant had no effect on hatchling morphology, hatching success, or emergence success. It also had no effect on the ability of hatchlings to orient toward the ocean. However, the pesticide granules attracted more predators than were seen at control nests. Thus, while AMDRO® might not directly impact reproductive success or hatchling behavior, it had the unanticipated effect of possibly increasing nest vulnerability to predators.
Show less
Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013264
Subject Headings: Fire ants, Loggerhead turtle--Effect of pesticides on, Caretta caretta
Format: Document (PDF)

Title: The role of air and waterborne odors in orientation and food detection in three species of marine turtles.
Creator: Kedzuf, Stephanie C., Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The cues used by marine turtles to locate foraging areas in the open ocean are largely unknown though some species (especially the green turtle [Chelonia mydas], the loggerhead [Caretta caretta], and the leatherback [Dermochelys coriacea]) somehow locate areas of high productivity. Loggerheads can detect airborne odors, but a capacity to orient has not yet been investigated. In this comparative study, tethered loggerheads and leatherbacks were exposed to dimethyl sulfide (DMS) or food odors...
Show moreThe cues used by marine turtles to locate foraging areas in the open ocean are largely unknown though some species (especially the green turtle [Chelonia mydas], the loggerhead [Caretta caretta], and the leatherback [Dermochelys coriacea]) somehow locate areas of high productivity. Loggerheads can detect airborne odors, but a capacity to orient has not yet been investigated. In this comparative study, tethered loggerheads and leatherbacks were exposed to dimethyl sulfide (DMS) or food odors in a laminar flow of air. Turtles did not orient into the air current. Free-swimming loggerheads and green turtles were also exposed to air- or waterborne food (squid) odor plus a neutral visual stimulus. Both species showed increases in swimming activity and biting behavior to both stimuli. These results suggest that airborne odors are likely not used to locate distant areas, but that they are used in localized food searching efforts.
Show less
Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004296
Subject Headings: Animal behavior, Animal orientation, Population genetics, Predation (Biology), Sea turtles -- Habitat, Sea turtles -- Life cycles, Wildlife conservation
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: Activity and Habitat Selection by Loggerhead (Caretta caretta L.) and Green Turtle (Chelonia mydas. L.) Hatchlings: A Laboratory and Field Study.
Creator: Smith, Morgan M., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description: Loggerhead and green turtle neonates migrate from Florida's coast during a 24-36 h frenzy. Post-frenzy loggerheads are often found in flotsam (Sargassum), while postfrenzy green turtles "disappear." This study compared the frenzy and post-frenzy activity of each species, their response to flotsam (in the laboratory and field), and the role of experience in habitat selection. Both species were most active during day I; activity thereafter declined (especially in loggerheads). Inactive...
Show moreLoggerhead and green turtle neonates migrate from Florida's coast during a 24-36 h frenzy. Post-frenzy loggerheads are often found in flotsam (Sargassum), while postfrenzy green turtles "disappear." This study compared the frenzy and post-frenzy activity of each species, their response to flotsam (in the laboratory and field), and the role of experience in habitat selection. Both species were most active during day I; activity thereafter declined (especially in loggerheads). Inactive loggerheads occupied Sargassum and open water (day or night) whereas inactive green turtles occupied Sargassum by day and both habitats at night. Exposure to Sargassum had no effect on the later habitat choices ofloggerheads, while exposed green turtles preferred Sargassum over plastic plants. In the field, both species preferred flotsam to open water, but occupied distinct microhabitats. Loggerheads preferred the mat surface while green turtles hid within the mat. Differences in activity and habitat selection likely reflect species-specific migratory and anti-predator strategies.
Show less
Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00000832
Subject Headings: Sea turtles--Ecology--Case studies, Wildlife conservation--Case studies, Habitat partitioning (Ecology), Adaptation (Biology)
Format: Document (PDF)

Title: Seafinding by the green turtle, Chelonia mydas: the orientation response is tuned to the lighting environment at the nesting beach.
Creator: Celano, Lisa, Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Hatchling marine turtles use visual cues to orient from their nest to the sea at night. However, the wavelengths of light that carry this information have not been properly documented, nor do we understand why they are favored. I measured wavelength irradiance at 20 nm intervals between 340 – 600 nm at a dark nesting beach and then, in the laboratory, determined the thresholds of the hatchlings for each λ that evoked a positive phototaxis. In this study, I show that green turtle hatchlings...
Show moreHatchling marine turtles use visual cues to orient from their nest to the sea at night. However, the wavelengths of light that carry this information have not been properly documented, nor do we understand why they are favored. I measured wavelength irradiance at 20 nm intervals between 340 – 600 nm at a dark nesting beach and then, in the laboratory, determined the thresholds of the hatchlings for each λ that evoked a positive phototaxis. In this study, I show that green turtle hatchlings are (i) most sensitive to the shorter (360 – 480 nm) light wavelengths. Those light energies (ii) dominated the available natural lighting at the nesting beach. They also (iii) presented a steep gradient in irradiance between a landward and seaward view, an important cue for orientation. I attribute the phototactic responses to “stimulus filtering”, the outcome of natural selection that optimizes behavioral responses (seafinding) according to their function, as well as when and where they occur.
Show less
Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013034
Subject Headings: Green turtle, Chelonia mydas, Phototaxis
Format: Document (PDF)

Title: Long-term analyses (1986-2018) of the Loggerhead Sea Turtle (Caretta caretta) nesting data from Keewaydin Island, Florida.
Creator: Hoover, Shelby R., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description: Few studies on marine turtles focus on the variation in reproductive performance of individual females. I use a long-term nesting data set (1986 – 2018) of individual loggerheads including information on 1,854 individuals, of which 853 were seen nesting multiple times. During this time, emergence success has declined while the number of females nesting, and the number of nests deposited has increased. Declining emergence success can be linked to an increase in predation in most recent years;...
Show moreFew studies on marine turtles focus on the variation in reproductive performance of individual females. I use a long-term nesting data set (1986 – 2018) of individual loggerheads including information on 1,854 individuals, of which 853 were seen nesting multiple times. During this time, emergence success has declined while the number of females nesting, and the number of nests deposited has increased. Declining emergence success can be linked to an increase in predation in most recent years; however, this does not fully explain the decline in emergence success over all years. Females were found to vary in productivity. Successful females were larger and deposited more eggs in nests. This study shows that an increasing in nesting numbers does not mean that productivity is increasing proportionally and that recovery efforts are uniformly successful. This study is also a powerful tool for understanding the reproductive strategies of individual female loggerheads.
Show less
Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013381
Subject Headings: Loggerhead turtle--Florida, Reproduction, Sea turtles--Nests, Predation (Biology)
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: Can hatchlings exposed to beach lighting recover, and orient normally offshore?.
Creator: Lorne, Jacquelyn Kay, Florida Atlantic University, Salmon, Michael
Abstract/Description: Artificial lighting disrupts sea turtle hatchling orientation from the nest to the sea. I studied how a light-induced landward crawl affects the ability of hatchlings to later crawl to the sea, and swim offshore from a dark beach. A brief (2 min) landward crawl had no effect on orientation, as long as waves (used as an orientation cue while swimming) were present. In the absence of waves (a flat calm sea), landward-crawling hatchlings failed to swim offshore while those crawling seaward were...
Show moreArtificial lighting disrupts sea turtle hatchling orientation from the nest to the sea. I studied how a light-induced landward crawl affects the ability of hatchlings to later crawl to the sea, and swim offshore from a dark beach. A brief (2 min) landward crawl had no effect on orientation, as long as waves (used as an orientation cue while swimming) were present. In the absence of waves (a flat calm sea), landward-crawling hatchlings failed to swim offshore while those crawling seaward were well oriented. A longer (2 h) landward crawl impaired the ability of hatchlings to crawl to the sea. These results demonstrate that previous exposure to artificial lighting compromises subsequent orientation, both on land and in the sea. On the basis of my results, I suggest several changes to current management practices, currently used when releasing misoriented turtles in the wild.
Show less
Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13400
Subject Headings: Sea turtles--Atlantic Coast (U S )--Geographical distribution, Light pollution, Animal orientation, Loggerhead turtle--Orientation, Animal navigation
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: Do Fiddler Crab Larvae Show Phenotypic Plasticity?.
Creator: Christopher, Catherine E., Salmon, Michael, Florida Atlantic University
Abstract/Description: Larval release by adult fiddler crabs occurs during the ebbing tides, but its timing relative to the day-night and tidal amplitude cycles depends upon tidal form (e.g., shows phenotypical plasticity). Crabs (Uca thayeri) from Florida's East Coast are exposed to semidiurnal tides and release their larvae at night, whereas crabs from Florida's West Coast exposed to mixed tides release their larvae during the afternoon. The purpose of this study was to determine whether the larvae could hatch at...
Show moreLarval release by adult fiddler crabs occurs during the ebbing tides, but its timing relative to the day-night and tidal amplitude cycles depends upon tidal form (e.g., shows phenotypical plasticity). Crabs (Uca thayeri) from Florida's East Coast are exposed to semidiurnal tides and release their larvae at night, whereas crabs from Florida's West Coast exposed to mixed tides release their larvae during the afternoon. The purpose of this study was to determine whether the larvae could hatch at times other than those correlated with the tidal form at their location. Clusters of eggs at similar stages of development, 24-72 h in advance of release, were reciprocally transferred between females from each coast. Release ofboth the transferred larvae and maternal clutch occurred synchronously, and at the time dictated by the female's tidal regime. These results suggest that larvae are phenotypically plastic with respect to hatching time and can either delay (West coast) or advance (East coast) their response to release signals from females.
Show less
Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00000733
Subject Headings: Cell differentiation, Adaptation (Biology), Evolution (Biology), Phenotypic plasticity
Format: Document (PDF)

Title: Do embedded roadway lights protect sea turtles?.
Creator: Bertolotti, Lesley L., Florida Atlantic University, Salmon, Michael
Abstract/Description: Pole-mounted street lighting on coastal roadways is often visible in adjacent areas. At roadways near sea turtle nesting beaches, these lights can disrupt the nocturnal orientation of hatchlings as they crawl from the nest to the sea. Our objective was to determine if an alternative lighting system (light-emitting diodes, embedded in the roadway pavement) prevented orientation disruption of loggerhead hatchlings. Hatchlings at the beach oriented normally when the embedded lights were on, or...
Show morePole-mounted street lighting on coastal roadways is often visible in adjacent areas. At roadways near sea turtle nesting beaches, these lights can disrupt the nocturnal orientation of hatchlings as they crawl from the nest to the sea. Our objective was to determine if an alternative lighting system (light-emitting diodes, embedded in the roadway pavement) prevented orientation disruption of loggerhead hatchlings. Hatchlings at the beach oriented normally when the embedded lights were on, or when all lighting was switched off. However, turtles showed poor orientation when exposed to pole-mounted street lighting. Light measurements revealed that street lighting was present at the beach, whereas embedded lighting was absent. I conclude that embedded lighting systems restrict light scatter, leaving adjacent habitats dark, and therefore protect the turtles from artificial lighting allowing for normal seafinding.
Show less
Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13203
Subject Headings: Loggerhead turtle, Animal navigation, Animal orientation, Sea turtles--Orientation, Exterior lighting--Environmental aspects, Light pollution
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: Entrainment of larval release in an intertidal crab ( Uca thayeri) after exposure to a different tidal regime: Testing the "plasticity" hypothesis.
Creator: Weaver, Ann, Florida Atlantic University, Salmon, Michael
Abstract/Description: Endogenous rhythms allow most organisms to synchronize their behavior and physiology with physical cycles that vary on a daily, lunar or annual cycle. Populations within species often show variation in the timing of functionally identical rhythms. This variation occurs because physical cycles may differ with geography. The purpose of this study was to determine whether hatching rhythms shown by fiddler crabs (Genus Uca) on one coastline could be entrained by the different tide patterns...
Show moreEndogenous rhythms allow most organisms to synchronize their behavior and physiology with physical cycles that vary on a daily, lunar or annual cycle. Populations within species often show variation in the timing of functionally identical rhythms. This variation occurs because physical cycles may differ with geography. The purpose of this study was to determine whether hatching rhythms shown by fiddler crabs (Genus Uca) on one coastline could be entrained by the different tide patterns present at another coastline. To test this I transferred breeding females (Uca thayeri) from mangroves on the west coast of Florida to mangroves on the east coast. On the west coast, females are exposed to "mixed" tides; most release their larvae during the day or night (early summer), or during the day (mid- to late summer). On the east coast, females are exposed to "semidiurnal" tides; they release their larvae between dusk and midnight. After four weeks of exposure to the East Coast tides, crabs from the West Coast showed hatching rhythms identical to the resident crabs. This change indicates that the crabs show behavioral (phenotypic) "plasticity". These observations provide further evidence for the adaptive value of behavioral plasticity.
Show less
Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/15774
Subject Headings: Fiddler crabs--Eggs, Fiddler crabs--Adaptation, Biological rhythms
Format: Document (PDF)

Title: Home range and movements of juvenile Atlantic green turtles (Chelonia mydas L.) on shallow reef habitats in Palm Beach, Florida, United States of America.
Creator: Makowski, Christopher, Florida Atlantic University, Salmon, Michael
Abstract/Description: This study's objectives were to determine if coastal (shallow-water, oceanic reef) aggregations of juvenile green turtles (Chelonia mydas L.) in Palm Beach, Florida occupied distinct home ranges and how these home ranges compared in size and resource availability with those studied elsewhere. Six immature green turtles were captured, measured, and subjected to esophageal lavage to determine diet. Each turtle was returned to its initial capture site within 24 h with an ultrasonic transmitter...
Show moreThis study's objectives were to determine if coastal (shallow-water, oceanic reef) aggregations of juvenile green turtles (Chelonia mydas L.) in Palm Beach, Florida occupied distinct home ranges and how these home ranges compared in size and resource availability with those studied elsewhere. Six immature green turtles were captured, measured, and subjected to esophageal lavage to determine diet. Each turtle was returned to its initial capture site within 24 h with an ultrasonic transmitter used to track movements. All turtles were <65 cm SCL, had ingested similar macroalgae, and occupied markedly small home ranges (mean = 2.38 +/- 1.78 km 2), largely restricted to the reef itself. Diving and feeding activity peaked during the day; at night, activity was minimal. The food and sleeping site resource distribution at this specific location coincides with the turtles' home range size and shape, with considerable overlap of core areas.
Show less
Date Issued: 2004
PURL: http://purl.flvc.org/fcla/dt/13160
Subject Headings: Sea turtles--Florida--Palm Beach, Animal behavior, Wildlife conservation, Green turtle--Florida--Palm Beach
Format: Document (PDF)

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: 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: Nest caging as a sea turtle management strategy: Do the benefits outweigh the costs on urban beaches?.
Creator: Adamany, Stephanie Lynne., Florida Atlantic University, Salmon, Michael
Abstract/Description: Caging of sea turtle nests has used by City of Boca Raton's sea turtle conservation program to deter terrestrial predators and reduce human disturbance. The juxtaposition of nest cages and artificial lighting may pose serious threats to hatchlings. I addressed possible negative effects of cages on sea turtle hatchlings' seafinding abilities and potential "cage-trapping" under natural and artificially illuminated conditions. Cages did not effect hatchling orientation on artificially...
Show moreCaging of sea turtle nests has used by City of Boca Raton's sea turtle conservation program to deter terrestrial predators and reduce human disturbance. The juxtaposition of nest cages and artificial lighting may pose serious threats to hatchlings. I addressed possible negative effects of cages on sea turtle hatchlings' seafinding abilities and potential "cage-trapping" under natural and artificially illuminated conditions. Cages did not effect hatchling orientation on artificially illuminated or dark beaches. Hatchlings did not experience any delay in cage escape on dark beaches, but a significant number were trapped inside the cages on artificially illuminated beaches. The highest incidence of trapping occurred on nights surrounding a new moon. Disoriented hatchlings exited cages either after city lighting was reduced (past midnight) or as natural levels of illumination increased shortly before sunrise. When cages were darkened all turtles escaped but many still exhibited signs of disorientation.
Show less
Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/15312
Subject Headings: Sea turtles--Florida, Sea turtles--Nests
Format: Document (PDF)

Title: Seafinding orientation of hatchlings exposed to filtered lighting: Effects of varying beach conditions.
Creator: Tuxbury, Susan Mary., Florida Atlantic University, Salmon, Michael
Abstract/Description: Under normal conditions, hatchling sea turtles crawl toward the ocean but streetlights placed on coastal roadways can attract the turtles toward land. Two light filters were designed to exclude the shorter light wavelengths most attractive to turtles. I did laboratory tests to determine if green turtle and loggerhead hatchlings oriented normally ("seaward") in the presence of filtered lighting. Light passed through either filter (#2422 acrylic and NLW) attracted the turtles unless coastal...
Show moreUnder normal conditions, hatchling sea turtles crawl toward the ocean but streetlights placed on coastal roadways can attract the turtles toward land. Two light filters were designed to exclude the shorter light wavelengths most attractive to turtles. I did laboratory tests to determine if green turtle and loggerhead hatchlings oriented normally ("seaward") in the presence of filtered lighting. Light passed through either filter (#2422 acrylic and NLW) attracted the turtles unless coastal cues (an elevated horizon) were strong or background (full moon) illumination was present. Green turtles and loggerheads responded differently to the same filters, indicating that neither filter provided adequate protection for both species. I conclude that these filters fail to protect the turtles. Conventional forms of light control (shielding and/or lowering light fixtures, decreasing wattage, or turning off problem lights) remain the best way to shield turtles from the harmful effects of artificial lighting.
Show less
Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/12804
Subject Headings: Sea turtles, Light pollution
Format: Document (PDF)

Loggerhead turtle (11)	+ -
Animal navigation (5)	+ -
Animal orientation (5)	+ -
Predation (Biology) (5)	+ -
Sea turtles--Orientation (4)	+ -

Animal behavior (3)	+ -
Leatherback turtle (3)	+ -
Light pollution (3)	+ -
Sea turtles--Nests (3)	+ -
Spectral sensitivity (3)	+ -
Adaptation (Biology) (2)	+ -
Chelonia mydas (2)	+ -
Green turtle (2)	+ -
Loggerhead turtle--Florida (2)	+ -
Phototaxis (2)	+ -
Sea turtles (2)	+ -
Sea turtles--Florida (2)	+ -
Wildlife conservation (2)	+ -
Animal communication (1)	+ -
Animal migration--Florida (1)	+ -
Animal orientation--Florida (1)	+ -
Animal sounds (1)	+ -
Atlantic spotted dolphin--Behavior (1)	+ -
Audiometry (1)	+ -
Beach nourishment (1)	+ -
Biological rhythms (1)	+ -
Caretta caretta (1)	+ -
Cell differentiation (1)	+ -
Conservation biology (1)	+ -
Crabs--Reproduction (1)	+ -

Charles E. Schmidt College of Science (13)	+ -
Department of Biological Sciences (13)	+ -
Wyneken, Jeanette (2)	+ -
Adamany, Stephanie Lynne. (1)	+ -
Barrett, Christie A. (1)	+ -

Bertolotti, Lesley L. (1)	+ -
Broadwell, Ann L. (1)	+ -
Burris, Jennifer. (1)	+ -
Celano, Lisa (1)	+ -
Christopher, Catherine E. (1)	+ -
Constantino, Maricela Alcantara. (1)	+ -
DeCarlo, Lisa Joy. (1)	+ -
Field, Angela (1)	+ -
Gerstein, Edmund Roy (1)	+ -
Glenn, Lawrence (1)	+ -
Gless, Jodie M. (1)	+ -
Gocke, Judith P. (1)	+ -
Goff, Matthew Douglas (1)	+ -
Hoover, Shelby R. (1)	+ -
Kedzuf, Stephanie C. (1)	+ -
Kellmeyer, Kay (1)	+ -
Light, Phillip Richard (1)	+ -
Lorne, Jacquelyn Kay (1)	+ -
Madrak, Sheila Veronica (1)	+ -
Makowski, Christopher (1)	+ -
Mroziak, Melissa Lynn (1)	+ -
Nelson, Kristen Ann (1)	+ -
Niland, Hannah (1)	+ -

Search In

Pages

Pages

Sort Results By:

Narrow results by:

Collection

Topical Subject

Genre

Type of Resource

Language

Creator

Format

Owner