Using Science to Improve the BLM Wild Horse and Burro Program: A Way Forward reviews the science that underpins the Bureau of Land Management's oversight of free-ranging horses and burros on federal public lands in the western United States, concluding that constructive changes could be implemented. The Wild Horse and Burro Program has not used scientifically rigorous methods to estimate the population sizes of horses and burros, to model the effects of management actions on the animals, or to assess the availability and use of forage on rangelands. Evidence suggests that horse populations are growing by 15 to 20 percent each year, a level that is unsustainable for maintaining healthy horse populations as well as healthy ecosystems. Promising fertility-control methods are available to help limit this population growth, however. In addition, science-based methods exist for improving population estimates, predicting the effects of management practices in order to maintain genetically diverse, healthy populations, and estimating the productivity of rangelands. Greater transparency in how science-based methods are used to inform management decisions may help increase public confidence in the Wild Horse and Burro Program.
Dragonflies and Damselflies documents the latest advances in odonate biology and relates these to a broader ecological and evolutionary research agenda. Despite being one of the smallest insect orders, dragonflies offer a number of advantages for both laboratory and field studies. In fact, they have been crucial to the advancement of our understanding of insect ecology and evolution. This book provides a critical summary of the major advances in these fields. Contributions from many of the leading researchers in dragonfly biology offer new perspectives and paradigms as well as additional, unpublished, data. The editor has carefully assembled a mix of theoretical and applied chapters (including those addressing conservation and monitoring) and achieves a balance of emerging and established research topics, providing suggestions for future study in each case. This accessible text is not about dragonflies per se but an essential source of knowledge that describes how different sets of evolutionary and ecological principles/ideas have been tested on a particular taxon. It will therefore be suitable for graduate students and researchers in entomology, evolutionary biology, population and behavioural ecology, and conservation biology. It will of course be of particular interest and use to those working on insects and an indispensable reference text for odonate biologists.
Every day, biologists in parkas, raincoats, and rubber boots go into the field to capture and mark a variety of animal species. Back in the office, statisticians create analytical models for the field biologists' data. But many times, representatives of the two professions do not fully understand one another's roles. This book bridges this gap by helping biologists understand state-of-the-art statistical methods for analyzing capture-recapture data. In so doing, statisticians will also become more familiar with the design of field studies and with the real-life issues facing biologists. Reliable outcomes of capture-recapture studies are vital to answering key ecological questions. Is the population increasing or decreasing? Do more or fewer animals have a particular characteristic? In answering these questions, biologists cannot hope to capture and mark entire populations. And frequently, the populations change unpredictably during a study. Thus, increasingly sophisticated models have been employed to convert data into answers to ecological questions. This book, by experts in capture-recapture analysis, introduces the most up-to-date methods for data analysis while explaining the theory behind those methods. Thorough, concise, and portable, it will be immensely useful to biologists, biometricians, and statisticians, students in both fields, and anyone else engaged in the capture-recapture process.
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.
Ecological Methods by the late T.R. E. Southwood and revised over the years by P. A. Henderson has developed into a classic reference work for the field biologist. It provides a handbook of ecological methods and analytical techniques pertinent to the study of animals, with an emphasis on non-microscopic animals in both terrestrial and aquatic environments. It remains unique in the breadth of the methods presented and in the depth of the literature cited, stretching right back to the earliest days of ecological research. The universal availability of R as an open source package has radically changed the way ecologists analyse their data. In response, Southwood's classic text has been thoroughly revised to be more relevant and useful to a new generation of ecologists, making the vast resource of R packages more readily available to the wider ecological community. By focusing on the use of R for data analysis, supported by worked examples, the book is now more accessible than previous editions to students requiring support and ideas for their projects. Southwood's Ecological Methods provides a crucial resource for both graduate students and research scientists in applied ecology, wildlife ecology, fisheries, agriculture, conservation biology, and habitat ecology. It will also be useful to the many professional ecologists, wildlife biologists, conservation biologists and practitioners requiring an authoritative overview of ecological methodology.
A synthesis of contemporary analytical and modeling approaches in population ecology The book provides an overview of the key analytical approaches that are currently used in demographic, genetic, and spatial analyses in population ecology. The chapters present current problems, introduce advances in analytical methods and models, and demonstrate the applications of quantitative methods to ecological data. The book covers new tools for designing robust field studies; estimation of abundance and demographic rates; matrix population models and analyses of population dynamics; and current approaches for genetic and spatial analysis. Each chapter is illustrated by empirical examples based on real datasets, with a companion website that offers online exercises and examples of computer code in the R statistical software platform. Fills a niche for a book that emphasizes applied aspects of population analysis Covers many of the current methods being used to analyse population dynamics and structure Illustrates the application of specific analytical methods through worked examples based on real datasets Offers readers the opportunity to work through examples or adapt the routines to their own datasets using computer code in the R statistical platform Population Ecology in Practice is an excellent book for upper-level undergraduate and graduate students taking courses in population ecology or ecological statistics, as well as established researchers needing a desktop reference for contemporary methods used to develop robust population assessments.
Originally published in 1982, this reprint of the second edition of The Estimation of Animal Abundance and Related Parameters has been described as the "bible" of the field. Censuses of living populations are required for many purposes in wildlife management, fisheries and pest control and they are essential in policy making for the protection of the environment. In this book Professor Seber, one of the leading experts in the field, explains in detail the methods that have been developed by ecologists for estimating animal numbers and related parameters such as mortality and birth rates. He insists on the importance of experimental design and describes a great variety of statistical techniques that are required in analyzing the data obtained. These designs and techniques are classified for easy reference according to the particular types of problems encountered by the field worker and the kind of information that is available. The assumptions underlying practical methods in current use are fully examined, together with procedures for testing their validity. Each method is demonstrated by at least one worked example; in all there are over 90 such examples, mostly using data obtained from natural or free-ranging populations around the world. Ecologists will find this book - the first full-length treatment of its subject - a sound statistical assessment of methods which in the past were frequently developed on an intuitive basis; while applied mathematicians will benefit no less from a study of the interaction between mathematics and biology in this important branch of statistics. Field workers will be stimulated and helped by the real-life examples and the practical nature of the work. "George Seber's book became an instant classic following its publication in 1973. It dealt comprehensively with previously published research on methods for estimating abundance and demographic parameters of animal populations. Professor Seber provided detailed reviews of methods that were originally published with adequate statistical development, and he provided derivations and development for intuitive estimators that had been initially presented by ecologists. The second edition of the book was published in 1982 and included substantive additional coverage of "new" developments that had occurred since 1973. The 1982 book has become a citation classic and can be found on the bookshelf of every serious animal population ecologist and every biostatistician dealing with animal population data. For the 20 years since its publication, it has remained the only book of its kind. Many important methodological developments have occurred in animal estimation problems since 1982, but virtually all such methods represent extensions of the initial methods described by Seber (1982). Several excellent monographs and books have been written over the last 2 decades that deal in detail with particular subsets of the material in Seber (1982). What is remarkable is that these recent contributions have not superseded Seber's book, but are best viewed as supplements to his original comprehensive treatment. Thus, Seber's (1982) book can still be found on the bookshelf of every serious animal population ecologist and biostatistician. Now, in 2002, it is surrounded on the bookshelf by a handful of related books and monographs, but it has not lost its relevance or importance and remains the most detailed, comprehensive treatment of methods to estimate animal abundance and related parameters." Jim Nichols, Patuxent Wildlife Research Center, U.S. Geological Survey, Laurel, MD Professor Seber, Professor Emeritus at the University of Auckland, is regarded as the world's foremost authority on statistical methods for estimating the size of animal populations. His early work on capture-recapture methods was groundbreaking and the Jolly-Seber method still forms the basis of most modern work, more than 30 years after his first paper on the method in 1962.
The virtual impossibility of extracting the many different species from a habitat with equal efficiency by a single method (e.g. Nef, 1960). 1.1 Population estimates Population estimates can be classified into a number of different types; the most convenient classification is that adopted by Morris (1955), although he used the terms somewhat differently in a later paper (1960). 1.1.1 Absolute and related estimates The animal numbers may be expressed as a density per unit area of the ground of the habitat. Such estimates are given by nearest neighbour and related techniques (Chapter 2), marking and recapture (Chapter 3), by sampling a known fraction of the habitat (Chapter 4-6) and by removal sampling and random walk techniques (Chapter 7). Absolute population The number of animals per unit area (e.g. hectare, acre). It is almost impossible to construct a budget or to study mortality factors without the conversion of population estimates to absolute figures, for not only do insects often move from the plant to the soil at different developmental stages, but the amount of plant material is itself always changing. The importance of obtaining absolute estimates cannot be overemphasized.
