Diet and Habitat Use of Juvenile Hawksbill Turtles (Eretmochelys Imbricata) in the Gulf of California, Mexico

Diet and Habitat Use of Juvenile Hawksbill Turtles (Eretmochelys Imbricata) in the Gulf of California, Mexico
Author: Kara Satomi Reynolds
Publisher:
Total Pages: 33
Release: 2021
Genre:
ISBN:
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The hawksbill sea turtle (Eretmochelys imbricata) is an endangered species thought to spend their juvenile years in protected, nearshore areas before returning to their natal beaches to breed. We caught, measured, and sampled skin and anterior and posterior scutes from hawksbill turtles in a foraging ground around Isla San Jose, Gulf of California, Mexico. We analyzed the [delta]13C and [delta]15N values from tissues taken from mostly juvenile (96.4%) individuals, based upon morphometric measurements, as well as potential prey items to assess their foraging habits. A Bayesian mixing model analysis of the stable isotope values indicated hawksbills are consuming a primarily invertebrate-based diet supplemented by foraging on plant matter composed largely of seagrass and algae. The [delta]13C values from posterior scute samples increased with age, suggesting a potential location shift as younger turtles move from a more pelagic habitat to the nearshore foraging area at Isla San Jose.

The Biology of Sea Turtles, Volume II

The Biology of Sea Turtles, Volume II
Author: Peter L. Lutz
Publisher: CRC Press
Total Pages: 510
Release: 2002-12-17
Genre: Nature
ISBN: 1420040804
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The success of the first volume of The Biology of Sea Turtles revealed a need for broad but comprehensive reviews of major recent advances in sea turtle biology. Biology of Sea Turtles, Volume II emphasizes practical aspects of biology that relate to sea turtle management and to changes in marine and coastal ecosystems. These topics i

Spatial Ecology of Hawksbill Turtles (Eretmochelys Imbricata) in the Eastern Pacific Ocean

Spatial Ecology of Hawksbill Turtles (Eretmochelys Imbricata) in the Eastern Pacific Ocean
Author:
Publisher:
Total Pages: 59
Release: 2011
Genre:
ISBN:
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Elucidating spatio-temporal movements of organisms is an integral component of wildlife management and life-history characterization. In the case of hawksbill turtles (Eretmochelys imbricata), adults have typically been described as coral reef dwellers, with females undertaking long post-nesting migrations. Until recently, hawksbills were thought to have been functionally extirpated in the eastern Pacific Ocean, a perspective changed by the identification of several substantial nesting rookeries. These discoveries provided new opportunities for research and conservation. Here we report on a region-wide satellite telemetry effort that has tracked thirteen adult female hawksbills in the eastern Pacific. In contrast to patterns of habitat use around coral reefs exhibited by their Caribbean conspecifics, the majority of hawksbills in the eastern Pacific occupied home ranges in mangrove estuaries. Post-nesting migrations for all turtles were relatively short (range = 18.1 km - 283.1 km) for the taxon, with several individuals remaining in local habitats after nesting. Also in contrast to previous research, dive computers indicated that adult hawksbills dove to and spent the majority of their time in the top 10 meters of the water column. Our findings suggest that common perceptions of hawksbill habitat use, dive behavior and migrations, largely Caribbean-based, have overlooked some key characteristics of this species displayed by other populations. Moreover, the consistent use of mangrove habitats, use of superficial waters and non-migratory behaviors represent a new life-history paradigm for the species and may explain why hawksbills went virtually undetected in the eastern Pacific for decades. From a conservation standpoint, the spatially restricted, shallow and neritic life cycles of hawksbills in the eastern Pacific present both threats to and conservation opportunities for the species. Although a large proportion (>60%) of turtle location points fell within protected areas, many of these sites lack enforcement and monitoring. Our results underscore the importance of strengthening protected area management, mangrove conservation and hawksbill research and conservation in the eastern Pacific. Furthermore, our findings highlight the variability in life-history strategies that sea turtles and other longlived marine wildlife may exhibit among ocean regions.

The Leatherback Turtle

The Leatherback Turtle
Author: James R. Spotila
Publisher: JHU Press
Total Pages: 246
Release: 2015-10-30
Genre: Science
ISBN: 142141709X
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The most comprehensive book ever written on leatherback sea turtles. Weighing as much as 2,000 pounds and reaching lengths of over seven feet, leatherback turtles are the world’s largest reptile. These unusual sea turtles have a thick, pliable shell that helps them to withstand great depths—they can swim more than one thousand meters below the surface in search of food. And what food source sustains these goliaths? Their diet consists almost exclusively of jellyfish, a meal they crisscross the oceans to find. Leatherbacks have been declining in recent decades, and some predict they will be gone by the end of this century. Why? Because of two primary factors: human redevelopment of nesting beaches and commercial fishing. There are only twenty-nine index beaches in the world where these turtles nest, and there is immense pressure to develop most of them into homes or resorts. At the same time, longline and gill net fisheries continue to overwhelm waters frequented by leatherbacks. In The Leatherback Turtle, James R. Spotila and Pilar Santidrián Tomillo bring together the world’s leading experts to produce a volume that reveals the biology of the leatherback while putting a spotlight on the conservation problems and solutions related to the species. The book leaves us with options: embark on the conservation strategy laid out within its pages and save one of nature’s most splendid creations, or watch yet another magnificent species disappear.

Mixed Stock Analysis of Juvenile Hawksbill Sea Turtles (Eretmochelys Imbricata) at Brewers Bay and Hawksbill Cove, St. Thomas, USVI

Mixed Stock Analysis of Juvenile Hawksbill Sea Turtles (Eretmochelys Imbricata) at Brewers Bay and Hawksbill Cove, St. Thomas, USVI
Author: Jessica N. Levenson
Publisher:
Total Pages: 43
Release: 2020
Genre: Hawksbill turtle
ISBN:
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Marine turtles’ complex life histories present substantial challenges in identifying population boundaries and relationships due to their highly migratory behaviors, philopatry, and wide dispersal throughout large areas of tropical and subtropical latitudes. Mitochondrial DNA (mtDNA) research has identified rookery-specific haplotypes that represent isolated populations with potentially limited gene flow, which results in nesting populations having a unique genetic signature. Juvenile populations at dispersed foraging grounds are composed of a diverse genetic mixture from multiple nesting locations. Analysis of the genetic composition of turtles from foraging locations could inform general life history patterns like the variations in habitat use, migration, and dispersal and suggest the natal origin of specific populations. Brewers Bay and Hawksbill Cove (BBHC), in St Thomas US Virgin Islands has been the site of in water research on the movement and behavior of hawksbill sea turtles (Eretmochelys imbricata). However, no studies have focused on how they connect with nesting populations in the Caribbean. Therefore, we collected tissue samples from 59 juvenile hawksbill turtles that were hand-captured to genetically characterize the structure of this foraging ground using mitochondrial DNA. All turtles captured were within the juvenile size class and ranged from 19.5 cm to 65.0 cm curved carapace length. Recapture rates confirm residency within BBHC with 32 individuals being recaptured at least once between 2014 and 2019. Ten haplotypes were found; EiA01 appeared 24 times, EiA11 appeared 14 times, EiA09 appeared 6 times, EiA83 appeared 4 times, EiA02, EiA24, EiA41, and EiA43 each appeared 2 times, and EiA12 and EiA23 each appeared 1 time. These haplotypes were compared against previously characterized rookeries throughout the Caribbean to determine the most likely origins for the St. Thomas population. An analysis of the ten haplotypes using the program BAYES suggested that the biggest contributing source to this juvenile population was the leeward side of Barbados, with lesser but notable contributions from nesting populations from windward side of Barbados, Nicaragua, Guadeloupe, and Sandy Point, St. Croix. The results presented from this study are an important contribution to the baseline data of foraging ground connections to natal beaches, which is essential for designing management plans for population recovery.

Food webs and stable isotopes, volume II

Food webs and stable isotopes, volume II
Author: Jason Newton
Publisher: Frontiers Media SA
Total Pages: 212
Release: 2023-09-29
Genre: Science
ISBN: 2832533922
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Turtles of the United States and Canada

Turtles of the United States and Canada
Author: Carl H. Ernst
Publisher: JHU Press
Total Pages: 840
Release: 2009-06-15
Genre: Nature
ISBN: 0801891213
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Winner, 2011 Book Award, The Wildlife Society2009 Outstanding Academic Title, Choice Ernst and Lovich’s thoroughly revised edition of this classic reference provides the most updated information ever assembled on the natural histories of North American turtles. From diminutive mud turtles to giant alligator snappers, two of North America’s most prominent experts describe the turtles that live in the fresh, brackish, and marine waters north of Mexico. Incorporating the explosion of new scientific information published on turtles over the past fifteen years—including the identification of four new species—Ernst and Lovich supply comprehensive coverage of all fifty-eight species, with discussions of conservation status and recovery efforts. Each species account contains information on identification, genetics, fossil record, distribution, geographic variation, habitat, behavior, reproduction, biology, growth and longevity, food habits, populations, predators, and conservation status. The book includes range maps for freshwater and terrestrial species, a glossary of scientific names, an extensive bibliography for further research, and an index to scientific and common names. Logically organized and richly illustrated—with more than two hundred color photographs and fifty-two maps—Turtles of the United States and Canada remains the standard for libraries, museums, nature centers, field biologists, and professional and amateur herpetologists alike.