The Preservation of Species This book was written under the auspices of the Center for Philosophy and Public Policy, University of Maryland The Preservation of Species The Value of Biological Diversity EDITED BY BRYAN G. NORTON PRINCETON UNIVERSITY PRESS PRINCETON, NEWJERSEY Copyright © 1986 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, Guildford, Surrey All Rights Reserved Publication of this book has been aided by a grant from the Harold W. McGraw, Jr. Fund of Princeton University Press Library of Congress Cataloging in Publication Data will be found on the last printed page of this book First Princeton Paperback printing, 1988 This book has been composed in Linotron Sabon and Gill Sans Clothbound editions of Princeton University Press books are printed on acid-free paper, and binding materials are chosen for strength and durability. Paperbacks, although satisfactory for personal collections, are not usually suitable for library rebinding Printed in the United States of America by Princeton University Press Princeton, New Jersey For R. T. Contents Preface IX Introduction 3 Part I: The Problem Introduction to Part I 9 Species Leave the Ark One by One 13 Thomas E. Lovejoy 2 The Biology of Human-Caused Extinction 28 Geerat j. VermelJ 3 Social and Perceptual Factors in the Preservation of Animal Species 50 Stephen R. Kellert Part II: Values and Objectives Introduction to Part II 77 4 Human Preferences. Economics. and the Preservation of Species 79 Alan Randall 5 On the Inherent Danger of Undervaluing Species 110 Bryan G. Norton 6 On the Intrinsic Value of Nonhuman Species 138 j. Baird Callicott 7 Philosophical Problems for Environmentalism 173 Elliott Sober 8 Duties of Preservation 195 Donald H. Regan Part III: Management Considerations Introduction to Part III 223 vii Contents 9 On the Susceptibility of Different Species to Extinction: Elementary Instructions for Owners of a World 226 Lawrence B. Slobodkin 10 Species Protection and Management Decisions in an Uncertain World 243 Terry L Leitzell 11 Property Rights and Incentives in the Preservation of Species 255 Robert L. Carlton Epilogue 268 Bryan G. Norton Notes on Contributors 285 Selected Bibliography 289 Index 297 VlIl Preface The Center for Philosophy and Public Policy was established in 1976 at the University of Maryland in College Park to conduct research into the values and concepts that underlie public policy. Most other research into public policy is empirical: it assesses costs, describes constituencies, and makes predictions. The Center's research is conceptual and normative. It investigates the structure of arguments and the nature of values relevant to the formation, justification, and criticism of public policy. The results of its research are disseminated through workshops, conferences, teaching materials, the Center's newsletter, and books like this one. The essays presented here grew from the deliberations of a working group assembled by the Center. The group consisted of biological sci entists, social scientists, attorneys, resource managers from both the pri vate and public sector, and philosophers. The goals of the project were, first, to examine and evaluate the various reasons that have been and could be given for preserving nonhuman species from extinction and, second, to grapple with the difficult problem of priorities—what should be done when financial and other resources are insufficient to save all species? It was assumed at the outset that a rational answer to the prior ities question could only be stated in the context of a careful examination of the reasons for preserving species. The interdisciplinary group assembled was chosen in order to stimulate new thinking about a recalcitrant subject, rather than to represent stand ard, accepted positions. While we tried to ensure that all necessary tech nical expertise was available in the group, we tended to choose repre sentatives of the various professions and disciplines according to their reputation for creative thinking over a range of problem areas, in pref erence to narrow expertise on the problem at hand. We encouraged members to think broadly, abstractly, and "philosophically" about the applications of knowledge from the field of their expertise. We first gath ered in Washington, D.C., on December 4, 1981, to discuss the scope and objectives of the group, and each member accepted responsibility for addressing the endangered species problem from a particular point of view. We returned to Washington twice more to discuss each other's first drafts. These discussions shed light from diverse disciplines upon IX