Download or read book The Bases of Intra and Interpopulational Reproductive Variation and Their Demographic Consequences in the California Vole written by David T. Krohne and published by . This book was released on 1979 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Social Systems and Population Cycles in Voles written by R. Tamarin and published by Birkhäuser. This book was released on 2013-11-21 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Methoxychlor on the California Vole Microtus Californicus written by Nancy Elizabeth Amundson and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of endocrine disrupting substances on wildlife populations present a challenge for wildlife conservation. Toxicology analyses identifying physiological effects in individual animals cannot predict long term and indirect effects on populations and associated biotic communities. In an approach to better elucidate the relationship between responses in individual animals and population level effects, this research project identified physiological and behavioral effects of an estrogenic pesticide, methoxychlor, in a wild rodent species, the California vole, and using computer generated simulations, extrapolated those results into effects on long term vole population dynamics. Methoxychlor is a chlorinated pesticide that is a reproductive toxin in exposed rodents. The California vole, Microtus californicus, is an herbivorous rodent that occurs across a wide range of habitats throughout California. M. californicus is conducive to determining plant structure and composition in the habitats in which it occurs and is important prey species for both diurnal and nocturnal predators. I conducted a multi-generation laboratory study of the effects of methoxychlor, which functions physiologically as an estrogen agonist, on reproduction and behavior in M. californicus. Data generated from the studies was used to construct stage structured matrix population models to examine the potential effects of methoxychlor on M. californicus population dynamics under varying exposure scenarios. The physiological effects of methoxychlor on reproductive parameters varied depending on the exposure route and dose. Through both direct and in utero/lactation exposure, the lowest dose of methoxychlor significantly stimulated productivity relative to controls, while essentially inhibiting reproduction at a higher dose. This type of non-monotonic dose response is consistent with reported physiological effects of exposure to endocrine disrupting substances and indicates that linear, low-dose extrapolations for these substances are not appropriate for all species. Methoxychlor exposure also resulted in a highly skewed sex ratio in the non-exposed offspring of F1 generation voles that were exposed in utero and through weaning only. A long term alteration in metabolism of the F1 generation is postulated as a possible mechanism for the effect on the offspring sex ratio. Behavioral analyses of methoxychlor exposure were conducted on three hormone-mediated behaviors: activity levels, parenting behavior, and aggression, measured as running wheel activity, infanticide, and territoriality, respectively. The effects on behavior were consistent with exposure to estrogen. Methoxychlor significantly increased running wheel activity by in utero/lactation exposed female M. californicus when tested as adults. This result indicates that methoxychlor or its metabolites caused a permanent disruption to the CNS with respect to estrogen metabolism. Infanticide was significantly reduced in both parental adult dosed dams and by F1 in utero/lactation-exposed male/female pairs. The parental reduction in infanticide is postulated to be due to methoxychlor binding to estrogen receptors in the brain of the adult dams, whereas the long term effect on the F1 generation is suggestive of a permanent, epigenetic alteration. Territorial behavior/aggression of F1 in utero/lactation-exposed males tested as adults did not differ significantly between treated and control voles. Disruptions to activity levels and hormonally-mediated behaviors that regulate the social systems of Microtus spp. could alter the demographics of the population as well as impact long term population dynamics. The modeled population trajectories demonstrated that methoxychlor exposure could result in adverse impacts to long term vole population dynamics in natural habitats. The simulations identified increased population variability, calculated as the range of variation in abundance, associated with increased fecundity, which occurred in the methoxychlor-exposed populations. Fecundity input values were increased as a result of two distinct mechanisms: (1) reduced infanticide, which increased survival and (2) reduced (female-skewed) sex ratio. Maximum population variability occurred when the effect of increased activity level, which also was associated with methoxychlor exposure, was incorporated into the models. Variation in the standard deviation of the carrying capacity resulted in population extinctions for exposed populations, indicating that exposed populations could be vulnerable to local extinction as a result of increased environmental stochasticity. The results of my research indicate that the reproductive and behavioral effects of estrogenic substances like methoxychlor could result in significant negative impacts on vole population dynamics in natural habitats. These studies have demonstrated that multiple approaches, including multigenerational, behavioral, and population level analyses, provide useful insights for the identification of potential population level effects in wild species. Due to the importance of voles in the habitats in which they occur, alterations to vole population dynamics could have indirect effects on the productivity and stability of the associated ecological communities.
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1984 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1980 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Literature of Mammalogy written by and published by . This book was released on 1980 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supplement for Feb. 1974 includes Proposed revisions of society bylaws and rules.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1979 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Animal Dispersal written by N.C. Stenseth and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: 4.1.1 Demographic significance Confined populations grow more rapidly than populations from which dispersal is permitted (Lidicker, 1975; Krebs, 1979; Tamarin et at., 1984), and demography in island populations where dispersal is restricted differs greatly from nearby mainland populations (Lidicker, 1973; Tamarin, 1977, 1978; Gliwicz, 1980), clearly demonstrating the demographic signi ficance of dispersal. The prevalence of dispersal in rapidly expanding populations is held to be the best evidence for presaturation dispersal. Because dispersal reduces the growth rate of source populations, it is generally believed that emigration is not balanced by immigration, and that mortality of emigrants occurs as a result of movement into a 'sink' of unfavourable habitat. If such dispersal is age- or sex-biased, the demo graphy of the population is markedly affected, as a consequence of differ ences in mortality in the dispersive sex or age class. Habitat heterogeneity consequently underlies this interpretation of dispersal and its demographic consequences, although the spatial variability of environments is rarely assessed in dispersal studies.
Download or read book Wildlife Disease Ecology written by Kenneth Wilson and published by Cambridge University Press. This book was released on 2019-11-14 with total page 693 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduces readers to key case studies that illustrate how theory and data can be integrated to understand wildlife disease ecology.
Download or read book High Mountain Conservation in a Changing World written by Jordi Catalan and published by Springer. This book was released on 2017-08-03 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides case studies and general views of the main processes involved in the ecosystem shifts occurring in the high mountains and analyses the implications for nature conservation. Case studies from the Pyrenees are preponderant, with a comprehensive set of mountain ranges surrounded by highly populated lowland areas also being considered. The introductory and closing chapters will summarise the main challenges that nature conservation may face in mountain areas under the environmental shifting conditions. Further chapters put forward approaches from environmental geography, functional ecology, biogeography, and paleoenvironmental reconstructions. Organisms from microbes to large carnivores, and ecosystems from lakes to forest will be considered. This interdisciplinary book will appeal to researchers in mountain ecosystems, students and nature professionals. This book is open access under a CC BY license.
Download or read book Mammals of South America Volume 2 written by James L. Patton and published by University of Chicago Press. This book was released on 2015-03-09 with total page 1363 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second installment in a planned three-volume series, this book provides the first substantive review of South American rodents published in over fifty years. Increases in the reach of field research and the variety of field survey methods, the introduction of bioinformatics, and the explosion of molecular-based genetic methodologies have all contributed to the revision of many phylogenetic relationships and to a doubling of the recognized diversity of South American rodents. The largest and most diverse mammalian order on Earth—and an increasingly threatened one—Rodentia is also of great ecological importance, and Rodents is both a timely and exhaustive reference on these ubiquitous creatures. From spiny mice and guinea pigs to the oversized capybara, this book covers all native rodents of South America, the continental islands of Trinidad and Tobago, and the Caribbean Netherlands off the Venezuelan coast. It includes identification keys and descriptions of all genera and species; comments on distribution; maps of localities; discussions of subspecies; and summaries of natural, taxonomic, and nomenclatural history. Rodents also contains a detailed list of cited literature and a separate gazetteer based on confirmed identifications from museum vouchers and the published literature.
Download or read book The Evolution of Social Behaviour written by Michael Taborsky and published by Cambridge University Press. This book was released on 2021-08-26 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can the stunning diversity of social systems and behaviours seen in nature be explained? Drawing on social evolution theory, experimental evidence and studies conducted in the field, this book outlines the fundamental principles of social evolution underlying this phenomenal richness.To succeed in the competition for resources, organisms may either 'race' to be quicker than others, 'fight' for privileged access, or 'share' their efforts and gains. The authors show how the ecology and intrinsic attributes of organisms select for each of these strategies, and how a handful of straightforward concepts explain the evolution of successful decision rules in behavioural interactions, whether among members of the same or different species. With a broad focus ranging from microorganisms to humans, this is the first book to provide students and researchers with a comprehensive account of the evolution of sociality by natural selection.
Download or read book Comprehensive Dissertation Index Biological sciences A E written by and published by . This book was released on 1984 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology Abstracts written by and published by . This book was released on 1995 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coverage: 1982- current; updated: monthly. This database covers current ecology research across a wide range of disciplines, reflecting recent advances in light of growing evidence regarding global environmental change and destruction. Major ares of subject coverage include: Algae/lichens, Animals, Annelids, Aquatic ecosystems, Arachnids, Arid zones, Birds, Brackish water, Bryophytes/pteridophytes, Coastal ecosystems, Conifers, Conservation, Control, Crustaceans, Ecosyst em studies, Fungi, Grasses, Grasslands, High altitude environments, Human ecology, Insects, Legumes, Mammals, Management, Microorganisms, Molluscs, Nematodes, Paleo-ecology, Plants, Pollution studies, Reptiles, River basins, Soil, TAiga/tundra, Terrestrial ecosystems, Vertebrates, Wetlands, Woodlands.
Download or read book The Chromosome Complement written by Bernard John and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: material can serve both autocatalytic and heterocatalytic functions. Thus not only is it unique in itB capacity for self-replication but its base sequence determines the specificity of proteins. And enzyme proteins are immediately responsible for the peripheral metabolism which enables the organism to impose its own kind of order on the raw materials it absorbs. The course of development is determined not only by the nature of the genetic material but by its over-all amount and the relative frequency of the different functional units. Differential rates of epigenetic activity matter also. In theory, therefore, differential development within or even between individuals could be determined by the differential replication of the various genetic elements or by their differential activity. And further variation could arise by the differential transmission of these elements between cells. Indeed it would appear that all these possibilities are exploited by living systems. If like is to beget like, however, any genetic change which occurs during development must be undone, or else germinal units preserved from change must be set aside. As far as is known, genetic changes, even those involving only quantity or relative amounts, are reversible to only a very limited extent so that a change once done cannot be undone. Consequently genetic changes during the development of presumptive germ-lines are either non existant or minor and confined to a small class of un aggregated deter minants.
Download or read book Snakes written by Stephen J. Mullin and published by Cornell University Press. This book was released on 2011-08-15 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Destruction of habitat due to urban sprawl, pollution, and deforestation has caused population declines or even extinction of many of the world's approximately 2,600 snake species. Furthermore, misconceptions about snakes have made them among the most persecuted of all animals, despite the fact that less than a quarter of all species are venomous and most species are beneficial because they control rodent pests. It has become increasingly urgent, therefore, to develop viable conservation strategies for snakes and to investigate their importance as monitors of ecosystem health and indicators of habitat sustainability. In the first book on snakes written with a focus on conservation, editors Stephen J. Mullin and Richard A. Seigel bring together leading herpetologists to review and synthesize the ecology, conservation, and management of snakes worldwide. These experts report on advances in current research and summarize the primary literature, presenting the most important concepts and techniques in snake ecology and conservation. The common thread of conservation unites the twelve chapters, each of which addresses a major subdiscipline within snake ecology. Applied topics such as methods and modeling and strategies such as captive rearing and translocation are also covered. Each chapter provides an essential framework and indicates specific directions for future research, making this a critical reference for anyone interested in vertebrate conservation generally or for anyone implementing conservation and management policies concerning snake populations. Contributors: Omar Attum, Indiana University Southeast; Steven J. Beaupre, University of Arkansas; Xavier Bonnet, Centre National de la Recherche Scientifique; Frank T. Burbrink, College of Staten Island-The City University of New York; Gordon M. Burghardt, University of Tennessee; Todd A. Castoe, University of Colorado; David Chiszar, University of Colorado; Michael E. Dorcas, Davidson College; Lara E. Douglas, University of Arkansas; Christopher L. Jenkins, Project Orianne, Ltd.; Glenn Johnson, State University of New York at Potsdam; Michael Hutchins, The Wildlife Society; Richard B. King, Northern Illinois University; Bruce A. Kingsbury, Indiana University-Purdue University Fort Wayne; Thomas Madsen, University of Wollongong; Stephen J. Mullin, Eastern Illinois University; James B. Murphy, National Zoological Park; Charles R. Peterson, Idaho State University; Kent A. Prior, Parks Canada; Richard A. Seigel, Towson University; Richard Shine, University of Sydney; Kevin T. Shoemaker, College of Environmental Science and Forestry, State University of New York; Patrick J. Weatherhead, University of Illinois; John D. Willson, University of Georgia
Download or read book Relict Species written by Jan Christian Habel and published by Springer Science & Business Media. This book was released on 2009-12-03 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mankind has evolved both genetically and culturally to become a most successful and dominant species. But we are now so numerous and our technology is so p- erful that we are having major effects on the planet, its environment, and the b- sphere. For some years prophets have warned of the possible detrimental consequences of our activities, such as pollution, deforestation, and overfishing, and recently it has become clear that we are even changing the atmosphere (e. g. ozone, carbon dioxide). This is worrying since the planet’s life systems are involved and dependent on its functioning. Current climate change – global w arming – is one recognised consequence of this larger problem. To face this major challenge, we will need the research and advice of many disciplines – Physics, Chemistry, Earth Sciences, Biology, and Sociology – and particularly the commitment of wise politicians such as US Senator Al Gore. An important aspect of this global problem that has been researched for several decades is the loss of species and the impoverishment of our ecosystems, and hence their ability to sustain themselves, and more particularly us! Through evolutionary time new species have been generated and some have gone extinct. Such extinction and regeneration are moulded by changes in the earth’s crust, atmosphere, and resultant climate. Some extinctions have been massive, particularly those asso- ated with catastrophic meteoric impacts like the end of the Cretaceous Period 65Mya.
