Download or read book Patterns and Consequences of Individual Variation in the Nest site Preferences of Two Species of Sea Turtle written by Stephanie Jill Kamel and published by . This book was released on 2006 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maternal behaviours, such as nest-site choice, can be major determinants of offspring phenotype and fitness. In egg-laying species, incubation environment can influence offspring body size, performance, survival and sex. This thesis focuses on variation among females in maternal nest-site choice and the consequences that this variation can have for offspring survival and performance. I investigated nest-site selection in leatherback (Dermochelys coriacea) and hawksbill (Eretmochelys imbricata) sea turtles at three levels: (i) in two species of sea turtle nesting in different environments, (ii) within populations of the same species and (iii) within individual females both within and across nesting seasons. In both species, evidence was found for individual-level nest-site preferences. This was an unexpected result for leatherbacks, as it had long been assumed that females placed their nests randomly due to the unpredictability of their environment. Results were more striking in hawksbills, with individuals exhibiting remarkably high repeatability for nest-site microhabitat characteristics, both within and across nesting seasons. Some females preferred nesting in the forest, some in the forest edge and others still in open areas. With a few exceptions, hatching success and sea-finding ability were similar in all beach microhabitats. This raises the question of what, if not differential offspring survival, is maintaining these preferences. Frequency-dependent selection, wherein females gain a fitness advantage by producing the rare sex, is one possibility. This idea gains some support from the finding that beach temperatures varied dramatically by microhabitat: nests laid in the forest were exposed to male-producing temperatures while those in less vegetated areas were warmer and more female producing. A related aspect of this work has been to consider the conservation implications of nest-site choice. Using seasonal beach temperatures and the distribution of hawksbill nests, I estimated a balanced primary sex ratio, a situation that is likely to change if the current rates of island deforestation in the Caribbean continue. It also appears that Guadeloupe hosts one of the largest hawksbill populations in this region, indicating that data from this nesting beach are critical for developing a more robust demographic picture of Caribbean hawksbills.
Download or read book Temperature Dependent Sex Determination in Vertebrates written by Nicole Valenzuela and published by Smithsonian Institution Scholarly Press. This book was released on 2004 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by the world's foremost authorities on the subject, with essays by leading scholars in the field, this work shows how the sex of reptiles and many fish is determined not by the chromosomes they inherit but by the temperature at which incubation takes place.
Download or read book 2000 IUCN Red List of Threatened Species written by Craig Hilton-Taylor and published by IUCN. This book was released on 2000 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Release of the 2000 Red List is a major landmark for IUCN. It is the first time that listings of animals and plants have been combined and the first time that the Red List has been produced on CD-ROM. The 2000 Red List combines new assessmentsincluding all bird species, many antelope and bat species, most primates and sharks, all Asian freshwater turtles, more molluscs, and many otherswith those from previous publications. The combination of animals and plants into a single list containing assessments of more than 18,000 taxa (11,000 of which are threatened species) and the move towards improved documentation of each species on the list means that a hard-copy version of the Red List would run to several volumes. This, combined with the fact that the Red List will be updated annually, led to the decision to release the Red List in electronic format, via the World Wide Web and as a CD-ROM.
Download or read book Research and Management Techniques for the Conservation of Sea Turtles written by and published by . This book was released on 1999 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Leatherback Turtle written by James R. Spotila and published by JHU Press. This book was released on 2015-10-30 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Biology of Sea Turtles Volume II written by Peter L. Lutz and published by CRC Press. This book was released on 2002-12-17 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Sea turtles in the Mediterranean Distribution threats and conservation priorities written by Paolo Casale and published by IUCN. This book was released on 2010 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Anthropogenic Litter written by Melanie Bergmann and published by Springer. This book was released on 2015-06-01 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes how man-made litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers contributed to the broad awareness of marine litter as a problem of global significance. The authors summarise more than five decades of marine litter research, which receives growing attention after the recent discovery of great oceanic garbage patches and the ubiquity of microscopic plastic particles in marine organisms and habitats. In 16 chapters, authors from all over the world have created a universal view on the diverse field of marine litter pollution, the biological impacts, dedicated research activities, and the various national and international legislative efforts to combat this environmental problem. They recommend future research directions necessary for a comprehensive understanding of this environmental issue and the development of efficient management strategies. This book addresses scientists, and it provides a solid knowledge base for policy makers, NGOs, and the broader public.
Download or read book Sea Turtle Research and Conservation written by Brad Nahill and published by Academic Press. This book was released on 2020-11-27 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea Turtles: Field Research and Conservation is a comprehensive reference of experiences with sea turtle species from global experts. This book looks at the human side of protecting and studying these unique animals around the world, as well as the challenges involved, such as cultural differences and conducting research in remote locations. Led by a renowned expert in sea turtle conservation, this book addresses the largest issue facing sea turtle species currently; nearly all species of sea turtles are endangered due to poaching, fishing snares, climate change, and more. Chapters in this book range from the use of cutting-edge technology to learn more about this elusive reptile, to working with communities with long histories of sea turtle trade and consumption. It provides readers with firsthand accounts of sea turtle conservation efforts from conservationists based around the world and offers important suggestions and solutions for ensuring the future of these sea turtle species. Sea Turtles: Field Research and Conservation is the ideal resource for field biologist and marine conservationists, specifically those working in marine herpetology and with sea turtle species. Policymakers concerned with marine conservation, wildlife protection, and sustainable development, will also find this a useful reference for efforts and directions to enact change and save sea turtles from extinction. Offers examples of groundbreaking technology to conduct noninvasive sea turtle research Written by global experts working in the field to study and protect sea turtle species Includes human-to-human case studies and advice for collaborating with cultures and communities to save these endangered animals
Download or read book Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations written by Susan E. H. Piacenza and published by . This book was released on 2016 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased 5.7% year−1 since 1973, but wide fluctuations in census counts of nesting females make recovery diagnosis difficult. For effective management planning, it is critical to have the best information possible on vital rates, and to determine the best tools and practices for incorporating vital rate information, particularly variability, into population models to assess population size and status. Process and observation errors, compounded by late maturity, obscure the relationship between trends on the nesting beach and the entire population. Using sea turtle nesting beach surveys as a population index for assessment is problematic, yet often pragmatic because this is the only population index that is easily accessible. It is advantageous to use a modelling approach that estimates interannual variability in life history traits, accounts for uncertainty from individual-level variability, and allows for population dynamics to emerge from individual behaviors. To this end, I analyzed a long-term data set of marked green sea turtles to determine the degree of temporal variability in key life history traits. From this analysis, I built an agent-based model (ABM) to form the basis of a new assessment tool -- Monitoring Strategy Evaluation. In Chapter 2, I evaluated annual changes in demographic indicators (DIs) of 3,677 nesting green turtles from a 38-year tagging program in the Hawaiian Islands to determine if key life history traits are changing over time and in response to nester density. I used linear mixed models and multistate open robust design models to estimate several DIs and correlated them with nesting female counts. Mean nester carapace length and breeding probability were highly variable over time, suggesting shifts in age structure that could be due to recruitment. The top-ranked model predicted constant female survival over time. A significant positive relationship between the nesting population and breeding probability was evident, and breeding probability shows promise as an indicator of population recovery. This work contributes to a growing set of studies evaluating sea turtle demography for temporal variability and is the first for Hawaiian green turtles. In Chapter 3, I develop the Green Sea Turtle Agent-Based Model (GSTABM) to evaluate how recovery processes differ across disturbance types. The GSTABM incorporates individually variable age-at-maturity, clutch frequency and clutch size, annually variable breeding probability, environmental stochasticity and density dependence in hatchling production. The GSTABM simulates the process of population impact and recovery and the monitoring process, with observation error, on the nesting beach. The GSTABM captures the emergent patterns of interannual nesting variation, nester recruitment, and realistic population growth rates. Changes in survival rates of the nearshore age-stage classes directly affected adult and nester abundance, population growth rate and nester recruitment more than any of the other input parameters. In simulating 100 years of recovery, experimentally disturbed populations began to increase but did not fully return to pre-disturbance levels in adult and nester abundance, population growth or nester recruitment. In simulations with different levels of monitoring effort, adult abundance was poorly estimated, was influenced by population trajectory and disturbance type, and showed marginal improvements in accuracy with increased detection probability. Estimating recruitment showed improvements with increasing detection levels. In the GSTABM, variability in the nesting beach does not mirror variability in adult abundance. The GSTABM is an important tool to determine relationships with monitoring, population assessment, and the underlying biological processes driving changes in the population, and especially, changes on the nesting beach. In Chapter 4, I develop a new simulation-based tool: Monitoring Strategy Evaluation (MoSE) to determine which data source yields the most useful information for population assessments. The MoSE has three main components: the simulated "true" operating, observation, and estimation models. To explore this first use of MoSE, I apply different treatments of disturbance, sampling, and detection to the virtual "true" population, and then sample the nests or nesters, with observation error, to test if the observation "data" accurately diagnose population status indicators. Based on the observed data, I estimated adult abundance, nester recruitment, and population trend and compare them to the known values. I tested the accuracy of the estimated abundance when annually varying inputs of breeding probability, detection and clutch frequency were used instead of constants. I also explored the improvement of trend accuracy with increased study duration. Disturbance type and severity can have important and persistent effects on the accuracy of population assessments drawn from monitoring rookeries. Accuracy in abundance estimates may be most improved by avoiding clutch frequency bias in sampling and including annually varying inputs in the estimation model. Accuracy of nester recruitment may be most improved by increasing detection level and avoiding age-bias in sampling. The accuracy of estimating population trend is most influenced by the underlying population trajectory, disturbance type and disturbance severity. At least 10 years of monitoring data are necessary to accurately estimate population trend, and longer if juvenile age classes were disturbed and trend estimates occur during the recovery phase. The MoSE is an important tool for sea turtle biologists and conservation managers and allows biologists to make informed decisions regarding the best monitoring strategies to employ for sea turtles. This modeling framework is designed to provide an evaluation of monitoring program effectiveness to assist in planning future programs for sea turtles. Altogether, my research suggests certain life history traits of green sea turtles have important temporal variation that should be accounted for in population models, understanding the relationships between nesting and the total population is essential, and basing population assessments from nesting beach data alone is likely to result in incorrect or biased estimates of status indicators. The quantitative tools employed here can be applied to other sea turtle populations and will improve monitoring, and result in better estimates of current population trends and enhance conservation for all species of sea turtles.
Download or read book Decline of the Sea Turtles written by National Research Council and published by National Academies Press. This book was released on 1990-02-01 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores in detail threats to the world's sea turtle population to provide sound, scientific conclusions on which dangers are greatest and how they can be addressed most effectively. Offering a fascinating and informative overview of five sea turtle species, the volume discusses sea turtles' feeding habits, preferred nesting areas, and migration routes; examines their status in U.S. waters; and cites examples of conservation measures under way and under consideration.
Download or read book Synopsis of Biological Data on the Hawksbill Turtle Eretmochelys Imbricata Linnaeus 1766 written by W. N. Witzell and published by Food & Agriculture Org.. This book was released on 1983 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Evolution and Extinction of the Dinosaurs written by David E. Fastovsky and published by Cambridge University Press. This book was released on 2005-02-07 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2005 edition of The Evolution and Extinction of the Dinosaurs is a unique, comprehensive treatment of this fascinating group of organisms. It is a detailed survey of dinosaur origins, their diversity, and their eventual extinction. The book can easily be used as a teaching textbook for a class, but it is also written as a series of readable, entertaining essays covering important and timely topics appealing to non-specialists and all dinosaur enthusiasts: birds as 'living dinosaurs', the new feathered dinosaurs from China, 'warm-bloodedness'. Along the way, the reader learns about dinosaur functional morphology, physiology, and systematics using cladistic methodology - in short, how professional paleontologists and dinosaur experts go about their work, and why they find it so rewarding. The book is spectacularly illustrated by John Sibbick, a world-famous illustrator of dinosaurs, commissioned exclusively for this book.
Download or read book The Conservation Biology of Tortoises written by IUCN/SSC Tortoise and Freshwater Turtle Specialist Group and published by IUCN. This book was released on 1989 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Leatherback Turtle written by James R. Spotila and published by JHU Press. This book was released on 2015-10-30 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Recovery Plan for U S Population of Atlantic Green Turtle Chelonia Mydas written by and published by . This book was released on 1991 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Method for Detecting Nesting Activity Thermal Implications of Different Nesting Strategies and Activity Patterns of Ornate Box Turtles Terrapene Ornata written by Charles Rogers Tucker and published by . This book was released on 2013 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ornate box turtle (Terrapene ornata) is a small emydid terrestrial turtle that has experienced declines throughout its wide geographic range. In an effort to provide supporting research for a reintroduction program at the Upper Mississippi River National Wildlife and Fish Refuge in northern Illinois, I investigated the ecology of this cryptic species. I developed a method that uses automated radio telemetry to identify nesting activity, allowing me to non-disruptively collect eggs from a species in which nests are notoriously difficult to find, and to monitor the nesting activity of many more animals than would otherwise be possible. Nest searches revealed that some females in this population nest underground, a behavior that may have important implications for the sex ratios of this temperature-dependent species. Data loggers placed into nest cavities revealed that underground nesting did not affect mean incubation temperatures, but the behavior reduced thermal variation of incubation temperatures. Automated telemetry was also used to quantify activity patterns in this population, and revealed that relative humidity, precipitation and turtle reproductive status affect turtle activity, and that thermal extremes restrict activity on both daily and seasonal scales in this northerly population. Activity levels were lower during an unusually warm summer.
