Download or read book To Pup Or Not to Pup Using Physiology and Dive Behavior to Answer the Weddell Seal s Overwinter Question written by Michelle R. Shero and published by . This book was released on 2015 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Female Weddell seals (Leptonychotes weddellii) haul-out on the fast-ice surrounding the Antarctic continent in October and November each year to give birth to and nurse their pups. Breeding follows directly after weaning (December) and the annual molt begins in January-February. Animals reduce foraging efforts during the lactation and molting periods, but very little is known regarding the influence of this reduced activity on physiological condition. After a period of embryonic diapause, the annual molt coincides with embryo attachment and the start of active gestation. Consequently, female physiological condition at this time may influence reproductive success the following year. Overall female health and the ability to forage successfully throughout the gestation period (austral winter) may impact the likelihood that a pregnancy is brought to term. Therefore, this study tested whether overwinter changes in Weddell seal physiology and foraging efforts are reflected in reproductive outcomes the following year (i.e., to answer the over winter question of "to pup or not to pup?"). From 2010-2012, 100 (January-February: n = 53; October-November: n = 47) adult female Weddell seals were captured in Erebus Bay, Antarctica to assess overwinter changes in physiological condition and/or dive behavior that may be associated with reproductive success. Morphometric measurements and isotopic dilution procedures revealed that female Weddell seals gain ~10-15% of their body mass across the winter period, primarily in the form of blubber and lipid mass. The proportion of mass and lipid gain was similar regardless of whether females returned the following year and successfully gave birth, or did not produce a pup. Further, the amount of mass and energy acquired across gestation in the Weddell seal was markedly less than previously reported for other phocid species. Despite changes in activity patterns and body composition, Weddell seals maintained blood hemoglobin and muscle myoglobin concentrations across the winter. Therefore, Weddell seal total body oxygen stores and calculated aerobic dive limit (cADL) were conserved. This ensures that females have the physiological capabilities to effectively forage directly following the annual molt when they are at their leanest and must regain body mass and lipid stores. Although aerobic capacities did not change, dive effort varied considerably throughout the austral winter. Proxies of dive effort (duration, depth, %dives > cADL) were highest just after the molt (January-February) and just prior to the subsequent pupping season (August-September). Additionally, the proportion of each day spent diving increased mid-winter. Females that were observed the following year with a pup significantly increased all indices of foraging effort during the austral winter as compared to females that returned without a pup. This study is the first to identify and measure differences in dive efforts due to reproductive status, and indicates that successful reproduction is associated with greater foraging effort.
Download or read book Annual Cycles of Diving Behavior and Ecology of the Weddell Seal written by Michael Angelo Castellini and published by Univ of California Press. This book was released on 1992-01-01 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work details more than ten years of study in the Antarctic on the diving biology of Weddell seals, a species capable of diving over 600 meters and for as long as 82 minutes. The authors focus on seasonal diving patterns and geographical differences and discuss how diving patterns are influenced by the physical and ecological environment of the seals.
Download or read book Physiological and behavioral determinants of the aerobic dive limit in Weddell seal Leptonychotes weddellii pups written by J.M. BURNS and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of Diving Behavior and Physiology in Juvenile Weddell Seals Leptonychotes Weddellii in McMurdo Sound Antarctica written by Jennifer Moss Burns and published by . This book was released on 1997 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Weddell Seal written by Gerald L. Kooyman and published by Cambridge University Press. This book was released on 2009-06-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the environment and behaviour patterns of the Weddell seal. Based on his numerous expeditions to the Antarctic, Dr Kooyman has analysed the seal's diving physiology and acoustical biology. The seal's remarkable adaptation to its environment is evidenced in its ability to dive to 600 meters and return without ill effect and to remain submerged for more than one hour, even though it is an air-breathing animal. The seal holds a unique niche in the world's ecology; it occupies the most southern latitude of any mammal on a permanent basis. The study of this seal has provided important insights into methods of animal navigation, respiration and metabolism. Dr Kooyman is well known as an authority on the Weddell seal. During his fifteen trips to the Antarctic since 1961, he has studied the seal extensively. This book should appeal to marine biologists, animal physiologists and to all those with a serious interest in natural history and life in the Antarctic.
Download or read book Movements and diving behavior of weaned Weddell seal Leptonychotes weddellii pups written by J.M. BURNS and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bridging the Gap Between Pupping and Molting Phenology written by Roxanne Beltran and published by . This book was released on 2018 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Antarctica, the narrow window of favorable conditions constrains the life history phenology of female Weddell seals (Leptonychotes weddellii) such that pupping, breeding, foraging, and molting occur in quick succession during summer; however, the carry-over effects from one life history event to another are unclear. In this dissertation, I characterize the phenological links between molting and pupping, and evaluate feeding behavior and ice dynamics as mechanistic drivers. First, I review the contributions of natural and sexual selection to the evolution of molting strategies in the contexts of energetics, habitat, function, and physiology. Many polar birds and mammals adhere to an analogous biannual molting strategy wherein the thin, brown summer feathers/fur are replaced with thick, white winter feathers/fur. Polar pinnipeds are an exception to the biannual molting paradigm; most rely on blubber for insulation and exhibit a single molt per year. Second, I describe the duration and timing of the Weddell seal molt based on data from 4,000 unique individuals. In adult females, I found that successful reproduction delays the molt by approximately two weeks relative to non-reproductive individuals. Using time-depth recorder data from 59 Weddell seals at the crucial time between pupping and molting, I report a striking mid-summer shallowing of seal dive depths that appears to follow a vertical migration of fishes during the summer phytoplankton bloom. The seals experience higher foraging success during this vertical shift in the prey distribution, which allows them to re-gain mass quickly before the molt. Across four years of study, later ice break-out resulted in later seal dive shallowing and later molt. In combination, the data presented in this dissertation suggest that molting, foraging, and pupping phenology are linked in Weddell seals and are affected by ice break-out timing.
Download or read book Cow pup behaviour of the Weddell seal Leptonychotes weddelli Pinnipedia in McMurdo Sound Antarctica written by R.A. TEDMAN and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1970-12 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book The Evolution of Senescence in the Tree of Life written by Richard P. Shefferson and published by Cambridge University Press. This book was released on 2017-02-23 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: The existing theories on the evolution of senescence assume that senescence is inevitable in all organisms. However, recent studies have shown that this is not necessarily true. A better understanding of senescence and its underlying mechanisms could have far-reaching consequences for conservation and eco-evolutionary research. This book is the first to offer interdisciplinary perspectives on the evolution of senescence in many species, setting the stage for further developments. It brings together new insights from a wide range of scientific fields and cutting-edge research done on a multitude of different animals (including humans), plants and microbes, giving the reader a complete overview of recent developments and of the controversies currently surrounding the topic. Written by specialists from a variety of disciplines, this book is a valuable source of information for students and researchers interested in ageing and life history traits and populations.
Download or read book Heat Transfer written by Adrian Bejan and published by John Wiley & Sons. This book was released on 2022-04-05 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: HEAT TRANSFER Provides authoritative coverage of the fundamentals of heat transfer, written by one of the most cited authors in all of Engineering Heat Transfer presents the fundamentals of the generation, use, conversion, and exchange of heat between physical systems. A pioneer in establishing heat transfer as a pillar of the modern thermal sciences, Professor Adrian Bejan presents the fundamental concepts and problem-solving methods of the discipline, predicts the evolution of heat transfer configurations, the principles of thermodynamics, and more. Building upon his classic 1993 book Heat Transfer, the author maintains his straightforward scientific approach to teaching essential developments such as Fourier conduction, fins, boundary layer theory, duct flow, scale analysis, and the structure of turbulence. In this new volume, Bejan explores topics and research developments that have emerged during the past decade, including the designing of convective flow and heat and mass transfer, the crucial relationship between configuration and performance, and new populations of configurations such as tapered ducts, plates with multi-scale features, and dendritic fins. Heat Transfer: Evolution, Design and Performance: Covers thermodynamics principles and establishes performance and evolution as fundamental concepts in thermal sciences Demonstrates how principles of physics predict a future with economies of scale, multi-scale design, vascularization, and hierarchical distribution of many small features Explores new work on conduction architecture, convection with nanofluids, boiling and condensation on designed surfaces, and resonance of natural circulation in enclosures Includes numerous examples, problems with solutions, and access to a companion website Heat Transfer: Evolution, Design and Performance is essential reading for undergraduate and graduate students in mechanical and chemical engineering, and for all engineers, physicists, biologists, and earth scientists.
Download or read book Polar Bears written by IUCN/SSC Polar Bear Specialist Group. Working Meeting Oslo, Norway) and published by IUCN. This book was released on 1998 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shackleton s Journey Activity Book written by William Grill and published by . This book was released on 2015-10-01 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1892, New Mexico. A wolfpack roams the Currumpaw River Valley, preying on the vast cattle and sheep herds of the area. Their leader, Lobo possesses such cunning that local ranchers are unable to trap the pack. Due to his knowledge of wolf behaviour, Ernest Thompson Seton, a naturalist, is employed by ranchers to ride them of Lobo's pack.
Download or read book The Arctic in the Anthropocene written by National Research Council and published by National Academies Press. This book was released on 2014-07-31 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Once ice-bound, difficult to access, and largely ignored by the rest of the world, the Arctic is now front and center in the midst of many important questions facing the world today. Our daily weather, what we eat, and coastal flooding are all interconnected with the future of the Arctic. The year 2012 was an astounding year for Arctic change. The summer sea ice volume smashed previous records, losing approximately 75 percent of its value since 1980 and half of its areal coverage. Multiple records were also broken when 97 percent of Greenland's surface experienced melt conditions in 2012, the largest melt extent in the satellite era. Receding ice caps in Arctic Canada are now exposing land surfaces that have been continuously ice covered for more than 40,000 years. What happens in the Arctic has far-reaching implications around the world. Loss of snow and ice exacerbates climate change and is the largest contributor to expected global sea level rise during the next century. Ten percent of the world's fish catches comes from Arctic and sub-Arctic waters. The U.S. Geological Survey estimated that up to 13 percent of the world's remaining oil reserves are in the Arctic. The geologic history of the Arctic may hold vital clues about massive volcanic eruptions and the consequent release of massive amount of coal fly ash that is thought to have caused mass extinctions in the distant past. How will these changes affect the rest of Earth? What research should we invest in to best understand this previously hidden land, manage impacts of change on Arctic communities, and cooperate with researchers from other nations? The Arctic in the Anthropocene reviews research questions previously identified by Arctic researchers, and then highlights the new questions that have emerged in the wake of and expectation of further rapid Arctic change, as well as new capabilities to address them. This report is meant to guide future directions in U.S. Arctic research so that research is targeted on critical scientific and societal questions and conducted as effectively as possible. The Arctic in the Anthropocene identifies both a disciplinary and a cross-cutting research strategy for the next 10 to 20 years, and evaluates infrastructure needs and collaboration opportunities. The climate, biology, and society in the Arctic are changing in rapid, complex, and interactive ways. Understanding the Arctic system has never been more critical; thus, Arctic research has never been more important. This report will be a resource for institutions, funders, policy makers, and students. Written in an engaging style, The Arctic in the Anthropocene paints a picture of one of the last unknown places on this planet, and communicates the excitement and importance of the discoveries and challenges that lie ahead.
Download or read book The Antarctic Silverfish a Keystone Species in a Changing Ecosystem written by Marino Vacchi and published by Springer. This book was released on 2017-05-03 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book encompasses the body of available scientific information on the notothenioid fish Pleuragramma antarctica commonly known as Antarctic silverfish. This plankton-feeder of the intermediate trophic level is the most abundant fish in the coastal regions of high Antarctica, and plays a pivotal ecological role as the main prey of top predators like seals, penguins, whales and Antarctic toothfish. Broad circum-polar distribution, a key role in the Antarctic shelf pelagic ecosystem, and adaptations makes understanding the species’ likely response to environmental change relevant to foresee the potential responses at the local ecosystem level. Additionally, a detailed understanding of the abundance and trophic interactions of such a dominant keystone species is a vital element of informing the development of marine spatial planning and marine protected areas in the Antarctic continental shelf region. Experts in the field provide here unique insights into the evolutionary adaptation, eco-physiology, trophic ecology, reproductive and population ecology of the Antarctic silverfish and provide new clues about its vulnerability in facing the challenges of the ongoing environmental changes.
Download or read book Ecology written by Michael Begon and published by John Wiley & Sons. This book was released on 2020-11-17 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt: A definitive guide to the depth and breadth of the ecological sciences, revised and updated The revised and updated fifth edition of Ecology: From Individuals to Ecosystems – now in full colour – offers students and practitioners a review of the ecological sciences. The previous editions of this book earned the authors the prestigious ‘Exceptional Life-time Achievement Award’ of the British Ecological Society – the aim for the fifth edition is not only to maintain standards but indeed to enhance its coverage of Ecology. In the first edition, 34 years ago, it seemed acceptable for ecologists to hold a comfortable, objective, not to say aloof position, from which the ecological communities around us were simply material for which we sought a scientific understanding. Now, we must accept the immediacy of the many environmental problems that threaten us and the responsibility of ecologists to play their full part in addressing these problems. This fifth edition addresses this challenge, with several chapters devoted entirely to applied topics, and examples of how ecological principles have been applied to problems facing us highlighted throughout the remaining nineteen chapters. Nonetheless, the authors remain wedded to the belief that environmental action can only ever be as sound as the ecological principles on which it is based. Hence, while trying harder than ever to help improve preparedness for addressing the environmental problems of the years ahead, the book remains, in its essence, an exposition of the science of ecology. This new edition incorporates the results from more than a thousand recent studies into a fully up-to-date text. Written for students of ecology, researchers and practitioners, the fifth edition of Ecology: From Individuals to Ecosystems is anessential reference to all aspects of ecology and addresses environmental problems of the future.
Download or read book Marine Insects written by Lanna Cheng and published by North-Holland. This book was released on 1976 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first exhaustive review of literature on marine insects, which are defined in this volume as those that spend at least part of their life in association with the marine environment. Not only are true insects, such as the Collembola and insect parasites of marine birds and mammals, considered, but also other kinds of intertidal air-breathing arthropods, notably spiders, scorpions, mites, centipedes and millipedes, which live and feed with, or even on, the insects of marine habitats. The chapters, written by leading authorities, are divided into two sections, the first treating primarily ecological aspects, the second dealing with major groups of insects in marine environments.
