Animal Dispersal


Book Description

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.




Animal Biomarkers as Pollution Indicators


Book Description

Ecotoxicology is a relatively new scientific discipline. Indeed, it might be argued that it is only during the last 5-10 years that it has come to merit being regarded as a true science, rather than a collection of procedures for protecting the environment through management and monitoring of pollutant discharges into the environment. The term 'ecotoxicology' was first coined in the late sixties by Prof. Truhaut, a toxicologist who had the vision to recognize the importance of investigating the fate and effects of chemicals in ecosystems. At that time, ecotoxicology was considered a sub-discipline of medical toxicology. Subsequently, several attempts have been made to portray ecotoxicology in a more realistic light. Notably, both F. Moriarty (1988) and F. Ramade (1987) emphasized in their books the broad basis of ecotoxicology, encompassing chemical and radiation effects on all components of ecosystems. In doing so, they and others have shifted concern from direct chemical toxicity to man, to the far more subtle effects that pollutant chemicals exert on natural biota. Such effects potentially threaten the existence of all life on Earth. Although I have identified the sixties as the era when ecotoxicology was first conceived as a coherent subject area, it is important to acknowledge that studies that would now be regarded as ecotoxicological are much older. Wherever people's ingenuity has led them to change the face of nature significantly, it has not escaped them that a number of biological con sequences, often unfavourable, ensue.







Ecological Impacts of Toxic Chemicals


Book Description

Ecological Impacts of Toxic Chemicals presents a comprehensive, yet readable account of the known disturbances caused by all kinds of toxic chemicals on both aquatic and terrestrial ecosystems. Topics cover the sources of toxicants, their fate and distribution through the planet, their impacts on specific ecosystems, and their remediation by natural systems. Each chapter is written by well-known specialists in those areas, for the general public, students, and even scientists from outside this field. The book intends to raise awareness of the dangers of chemical pollution in a world dominated by industry and globalization of resources. Because the problems are widespread and far reaching, it is hoped that confronting the facts may prompt better management practices at industrial, agricultural and all levels of management, from local to governmental, so as to reduce the negative impacts of chemical contaminants on our planet.







Anticoagulant Rodenticides and Wildlife


Book Description

Commensal rodents pose health risks and cause substantial damage to property and food supplies. Rats have also invaded islands and pose a serious threat to native wildlife, particularly raptors and seabirds. Estimates of total damage from introduced rats range into the billions of dollars in developed countries. This book aims to provide a state-of-the-art overview of the scientific advancements in the assessment of exposure, effects and risks that currently used rodenticides may pose to non-target organisms in the environment, along with practical guidance for characterization of hazards. This will be discussed in relation to their efficacy, and the societal needs for rodent control, and discussion of risk mitigation and development of alternatives. The flow in the book is planned as: a. introduction and setting the scene b. problem description (risks and effects on non-targets and secondary poisoning, development of resistance) c. ; alternatives, regulation and risk mitigation d. conclusions and recommendations




Radioecological Techniques


Book Description

During the twenty years the authors have been associated with the field of radiation ecology, there has been a diversified and increasing use of radionuclides in applied and basic biological research. Prior to the advent of the atomic age in the 1940s the use of radionuclides as tracers was initiated, and following that period one observed a dramatically increased use in many disciplines. Concurrent with this increase there appeared many books and articles on radionuclide tech niques useful to biologists in general. Although only a few ecological applications were evident in these early years, ecologists were quick to see the opportunities available in their field. In the United States, major centers for such activities included Oak Ridge National Laboratory and the U. S. Atomic Energy Com mission's Savannah River Plant. At Oak Ridge National Laboratory Dr. Stanley I. Auerbach, director of ecological activities, encouraged with remarkable suc cess the use of tracers by his associates. Dr. Eugene P. Odum had the foresight to see that radionuclide tracers provided the means to solve many problems of interest to ecologists. Consequently, his research included some unique radio tracer applications at the Savannah River Plant. In addition he encouraged others involved in ecological activities at the Savannah River Plant to do likewise. Ecologists such as Dr. Robert C. Pendleton at the U. S. Atomic Energy Com mission's Hanford Works applied radionuclides in their research. To these early investigators and to those who followed we owe the oppportunity to write this book.




Handbook of Ecotoxicology


Book Description

Completely revised and updated with 18 new chapters, this second edition includes contributions from over 75 international experts. Also, a Technical Review Board reviewed all manuscripts for accuracy and currency. Focusing on toxic substance and how they affect the ecosystems worldwide, the book presents methods for quantifying and measuring ecotoxicological effects in the field and in the lab, as well as methods for estimating, predicting, and modeling in ecotoxicology studies. This is the definitive reference for students, researchers, consultants, and other professionals in the environmental sciences, toxicology, chemistry, biology, and ecology - in academia, industry, and government.