Download or read book Population Genetics and Mating System of Antarctic Fur Seals Arctocephalus Gazella at Livingston Island Antarctica written by Carolina Aimoré Bonin and published by . This book was released on 2012 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antarctic fur seals, Arctocephalus gazella, were hunted to near-extinction in the early 1800's, but have recovered during the past 70 years to re-colonize most of their historical range. The large South Georgia (SG) fur seal population has been considered the main source of immigrants that re-colonized other areas, including Livingston Island (LI). Despite being one of the most exploited marine mammal species, clear evidence for a genetic bottleneck is lacking and instead, exceptionally high genetic diversity has been detected. Nevertheless, little is known about population-level patterns of genetic structure, or how this species' polygynous mating system may influence such patterns. This thesis fills some of this knowledge gap via extensive efforts in the field and in the laboratory, where over 1,000 individual samples were processed to obtain data on 17 highly polymorphic microsatellite markers; of these, 365 were also sequenced for mtDNA hypervariable region 1. The results of this work uncovered : (i) unexpected genetic differentiation between SG and LI indicating that LI was re-colonized by immigrants from one or more sources in addition to SG, (ii) remarkably high male reproductive success at a low-density LI colony during four breeding seasons, suggesting reduced competition among males at LI relative to the high-density colony of Bird Island (SG) (iii) a low percentage of rematings among individuals over the course of a decade, which was surprising considering the high level of breeding site fidelity and male reproductive skew found in this species, and (iv) one case of multiple-paternity in Antarctic fur seals among twins, showing that females may often escape control of territorial males within a breeding period. Not only do these findings provide unique insights into the remarkable re-colonization of Antarctic fur seals, but they also emphasize the importance of satellite populations for harboring genetic diversity through a period of profound anthropogenic disturbance. Additionally, by revealing complexities within male and female breeding behavior, this work advances our overall understanding of polygyny, providing insight into how it might function under different population densities and how individuals may interact over the course of their lives within this mating system.
Download or read book Entanglement of Antarctic fur seals Arctocephalus gazella by marine debris at Cape Shirreff and San Telmo Islets Livingston Island Antarctica written by R. HUCKE-GAETE and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Reproductive Energetics of Antarctic Fur Seals Arctocephalus Gazella written by Birgitte Irene McDonald and published by . This book was released on 2009 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Status Biology and Ecology of Fur Seals written by John P. Croxall and published by . This book was released on 1987 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: 14 species summaries, 12 contributed papers and 5 rapporteurs' reports on fur seals throughout the world including the Pribilof Islands and Antarctica.
Download or read book Behavior and Ecology of the Northern Fur Seal written by Roger L. Gentry and published by Princeton University Press. This book was released on 2014-07-14 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the behavior and ecology of the northern fur seal, this book is a model long-term study of marine mammals, one that tests theory through both observation of undisturbed behavior and manipulative experiments on individuals. Here Roger Gentry draws on nearly two decades of research on three different islands to show how behavior among these seals changes with population size, sex ratio, and environment, to explain the behavior of the population beginning with individuals, and to generalize the results to other members of the eared seal family. In so doing, he offers one of the most comprehensive studies of its kind on any marine mammal species to date. Gentry shows that the species is driven by very different behavioral traits than have been assumed for it in the past. His book analyzes behavior on scales of hours to lifetimes, investigates the mating system, considers processes that underlie the mating system (site fidelity, behavioral estrus, and the development of territoriality), and addresses specific aspects of maternal strategy (female attendance behavior, pup growth, seasonal influences, and the effects of continental shelf width). Gentry contributes to knowledge about marine mammals by providing a very specific basis for interspecies comparisons, and he suggests a link between population trend and environmental regime shifts. He also guides the debate over seal mating systems from an interpretive to an empirical or experimental basis. Originally published in 1997. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
Download or read book Population size and breeding season of the Antarctic fur seal Arctocephalus gazella at Heard Island 1987 88 written by P.D. SHAUGHNESSY and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fur Seals and Sea Lions written by Roger Kirkwood and published by CSIRO PUBLISHING. This book was released on 2013-06-12 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fur seals and sea lions are charismatic, large carnivores that engage us with both their skill and playful antics. Although all species in Australian waters were harvested to near extinction 200 years ago, fur seals are recovering and are now common in near-shore waters across southern Australia. Sea lions, however, are endangered. Their populations appear not to have recovered like fur seals and are declining at some locations. Fur seals and sea lions are important top level predators and play an important role in Australia’s temperate marine ecosystems. Key threats they currently face relate to human activities, particularly interactions with fisheries. This book outlines the comparative evolutionary ecology, biology, life-history, behaviour, conservation status, threats, history of human interactions and latest research on the three species of otariids that live in the waters of southern Australia: the Australian fur seal, New Zealand fur seal and Australian sea lion. It also includes brief descriptions of Antarctic and Subantarctic seals that occupy the Antarctic pack-ice and remote Australian territories of Macquarie Island and Heard Island.
Download or read book Population Genetics of Antarctic Seals written by Caitlin Curtis and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: I developed and tested a protocol for determining the sex of individual pinnipeds using the sex-chromosome specific genes ZFX and ZFY. I screened a total of 368 seals (168 crabeater, Lobodon carcinophagus; 159 Weddell, Leptonychotes weddellii; and 41 Ross, Ommatophoca rossii) of known or unknown sex and compared the molecular sex to the sex assigned at the time of collection in the Ross and Amundsen seas, Antarctica. Discrepancies ranged from 0.0% - 6.7% among species. It is unclear, however, if mis-assignment of sex occurred in situ or in the laboratory. It also is possible, however, that the assigned morphological and molecular sex both are correct, owing perhaps to developmental effects of environmental pollution. I sequenced a portion (ca 475 bp) of the mitochondrial control region of Weddell seals (N = 181); crabeater seals (N = 143); and Ross seals (N = 41). I resolved 251 haplotypes with a haplotype diversity of 0.98 to 0.99. Bayesian estimates of theta from the program LAMARC ranged from 0.075 for Weddell seals to 0.576 for crabeater seals. I used the values of theta to estimate female effective population sizes (NEF), which were 40,700 to 63,000 for Weddell seals, 44,400 to 97,800 for Ross seals, and 358,500 to 531,900 for crabeater seals. Weddell seals and crabeater seals had significant, unimodal mean pairwise difference mismatch distributions (p = 0.56 and 0.36, respectively), suggesting that their populations expanded suddenly around 731,000 years ago (Weddell seals) and around 1.6 million years ago (crabeater seals). Both of these expansions occurred during times of intensified glaciations and may have been fostered by expanding pack ice habitat. Autosomal microsatellite based NEs were 147,850 for L. Weddellii, 344,950 for O. rossii, and 939,600 for L. carcinophagus. I screened one X-linked microsatellite (Lw18), which yielded a larger NE estimate for O. rossii than the other two species. Microsatellite NE estimates are compared with previously published mitochondrial NE estimates and this comparison indicates that the Ross seal may have a serially monogamous system of mating. I find no sign of a recent, sustained genetic bottleneck in any of the three species.
Download or read book Genetic analysis of twinning in Antarctic fur seals Arctocephalus gazella written by J.I. HOFFMAN and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial and temporal distribution of Antarctic fur seals Arctocephalus gazella on the breeding grounds at Bird Island South Georgia written by I.L. BOYD and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Male Reproductive Success Relatedness and the Mating System of Weddell Seals in Mcmurdo Sound Antarctica written by Thomas Scott Gelatt and published by . This book was released on 2001 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Analysis of Male Reproductive Success in the Antarctic Fur Seal Arctocephalus Gazella written by J. I. Hoffman and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Antarctic Seals written by Richard M. Laws and published by Cambridge University Press. This book was released on 1993-10-07 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite its remote and seemingly rigorous environment, the Antarctic is the world's most important habitat for seals, currently supporting more seals than all other parts of the world combined. As various national Antarctic programmes were established to study these animals, the need to standardize techniques became apparent. This book, arising from work by the Scientific Committee on Antarctic Research (Group of Specialists on Seals), gives a detailed account of well-tried and, where possible, agreed methodologies, techniques, procedures and rationale for the collection and initial analysis of data on the biology and population ecology of Antarctic seals. This volume will not only help facilitate comparisons between different regions of Antarctica, but will also provide a guide for those studying seals in other parts of the world and those carrying out research on other large mammal species.
Download or read book Pup production and distribution of breeding Antarctic fur seals Arctocephalus gazella at South Georgia written by I.L. BOYD and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The diet of Antarctic fur seals Arctocephalus gazella Peters during the breeding season at Heard Island written by K.A. Green and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic tagging reveals extreme site fidelity in territorial male Antarctic fur seals Arctocephalus gazella written by J.I. HOFFMAN and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Counts of the Antarctic Fur Seal Arctocephalus Gazella and Location of Colonies at Heard Island in the 1987 88 Summer written by S. D. Goldsworthy and published by National Gallery of Australia. This book was released on 1989 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
