Domestication Clive Roots Greenwood Press X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page DOMESTICATION X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page Recent Titles in Greenwood Guides to the Animal World Flightless Birds Clive Roots Nocturnal Animals Clive Roots Hibernation Clive Roots Animal Parents Clive Roots Domestication Clive Roots X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page DOMESTICATION Clive Roots Greenwood Guides to the Animal World GREENWOOD PRESS Westport, Connecticut • London X:/greenwood/Roots2/WORK/roots.3f 06/14/2007 3:14 PM Page Library of Congress Cataloging-in-Publication Data Roots, Clive, 1935– Domestication / Clive Roots. p. cm. — (Greenwood guides to the animal world, ISSN 1559–5617) Includes bibliographical references and index. ISBN 978–0–313–33987–5 (alk. paper) 1. Domestication—History. I. Title. SF41.R66 2007 636.009—dc22 2007016145 British Library Cataloguing in Publication Data is available. Copyright © 2007 by Clive Roots All rights reserved. No portion of this book may be reproduced, by any process or technique, without the express written consent of the publisher. Library of Congress Catalog Card Number: 2007016145 ISBN-13: 978–0–313–33987–5 ISBN-10: 0–313–33987–2 ISSN: 1559–5617 First published in 2007 Greenwood Press, 88 Post Road West, Westport, CT 06881 An imprint of Greenwood Publishing Group, Inc. www.greenwood.com Printed in the United States of America The paper used in this book complies with the Permanent Paper Standard issued by the National Information Standards Organization (Z39.48–1984). 10987654321 X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page For Jean For the many years of love, companionship, and shared concern for animals, from London Zoo to Vancouver Island X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page Contents Preface ix Introduction xi 1. Changing Nature 1 2. Fish 21 3. Amphibians 37 4. Reptiles 49 5. Birds 75 6. Mammals 103 7. Conservation by Domestication 143 8. Free Again 165 Glossary 187 Bibliography 193 Index 195 X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page Preface Evolution is a process of natural change resulting from competition and survival. Since life began on earth, escaping predators and competing for food, shelter, and mates required continual improvements to an animal’s lifestyle, and traits that aided survival were passed on to its offspring. The genetic composition of a population slowly altered as each generation improved to cope with new conditions, and even- tually these changes affected their appearance, internal functions, and behavior. In time these natural changes produced new species, some so superbly designed, and their adaptations so successful, that their evolutionary development stopped and they have remained the same for millions of years. But they are the exceptions, as most could not compete, and extinction from natural causes became an integral part of evolution. Although rapidly reproducing microscopic organisms can mutate quickly to challenge a new drug, change in the animal kingdom is constant but very slow. Major changes—for example, from amphibians to reptiles, and from dinosaurs to birds—took millions of years. The first single-celled life forms originated between three and four billion years ago, but the land vertebrates began to evolve only about 400 million years ago. The process was so slow that no one could expect to see the development of major new animals in their lifetime. But times have changed. In the last century, while natural evolution continued its slow and unnoticed course, another form of evolution was happening simultane- ously. It was totally unnatural and extremely rapid, and it has already produced new animals, many that differ considerably from their ancestors. The process is actually a very familiar one, at least in its original, prehistoric form, for it began when cavemen tamed the wolf. It is the controlled breeding of wild animals by man, known as domestication. X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page Introduction Until recently evolution was solely a natural process, where only the fittest survived. The losses were very high, for the fossil record shows that many animals could not compete, and the current living species may represent only 1 percent of all the ver- tebrates that have ever existed. This natural improvement of wild animals, resulting from evolutionary chance, continues at its very slow pace, but for several millennia a parallel process unconnected to survival has also changed animals. Called domes- tication, after domesticus, Latin for home, it resulted from man’s continual control of wild animals and their selection for certain characteristics. Domesticated animals are therefore man’s creations, and the process has produced many new animals, adapted to artificial conditions, and reliant on man for their food, shelter, and mates. The controlled animals eventually changed genetically, and this produced detectable differences between them and their wild ancestors. Although many animals had the opportunity to become domesticated, until the twentieth century man could not overcome the behavioral and physiological attrib- utes that prevented the regular breeding, or even the maintenance, of some species. The original domesticates bred easily and were mainly social creatures, accustomed to living in groups and therefore more amenable to human control and association. Their gregarious nature allowed them to establish positions within the hierarchy of the group rather than needing to defend territories of their own. But although a social (herd or pack) structure favored domestication, it was by no means a pre- requisite, as so often stated, for the African wild cat (ancestor of the cat), and the polecat (ancestor of the ferret) are certainly not social animals. Even golden ham- sters are actually bad-tempered, unsociable creatures, but they are more recent domesticates. Consequently, until the last century domesticated animals were restricted to our familiar pet and farm animals, such as dogs, cats, cattle, sheep, horses, chickens, and rabbits, plus a few lesser-known creatures like the ferret and guineafowl. These animals have been domesticated for millennia. The wolf X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page xii INTRODUCTION was the first to be controlled, presumably by cavemen, and others followed as man settled down and began cultivating crops and herding animals like sheep and goats. Great changes resulted from this long control, and many breeds of domesticated animals differ considerably from their ancestral stock, in size and shape (morpho- logically), in the manner in which they function (physiologically), and certainly in their behavior. The desirable characteristics for domestication were an animal’s value to man for supplying food, skins, and fiber, for draft, and for hunting. They had to be easy to feed, and those able to forage for themselves—herbivores such as cattle, sheep, and guinea pigs; and omnivores like the duck, junglefowl and wild boar—were prime candidates for control. A calm and tractable disposition was necessary, as was a temperament that allowed them to live in close proximity to man and to breed readily in an artificial environment. But there were obligations on the keeper’s side also, for domesticated animals are completely dependent on humans, who therefore have a moral duty to provide the best possible care. Surprisingly, between the control of the easily bred animals all those years ago and the beginning of the twentieth century, a period of several millennia, the domestication of new animals did not continue at the same pace; and there is a great gap between the old domesticates and the new ones. Attempts were made in ancient Egypt to domesticate many animals, including antelope, cranes, ibis, baboons, and perhaps even hyenas, although it is difficult to understand why, but none were suc- cessful. The turkey, canary, peafowl and ring-necked pheasant were the major spe- cies controlled during that period, when emphasis was placed upon improving the existing domesticated animals to better suit man’s purposes, rather than creating new ones. RECENT DOMESTICATION After centuries of inaction in the domestication of new species, during the last century, and especially in its latter half, there was an unprecedented escalation of controlled animal breeding that produced many changes. Dozens of animals that had rarely bred before began to reproduce regularly. It became relatively easy to breed pet and hobby species such as tree frogs, boa constrictors, bearded lizards, scarlet macaws, fennec foxes, and even hedgehogs. On farms, red deer, mink, and catfish were selectively bred—intentionally mated to achieve or eliminate a specific trait. Many wild animals, including shrews, geckos, and even pit vipers, were main- tained for numerous generations in research facilities. The new age of domestication was well under way, in two basic forms. There was the rapid commercial process intent on producing change, and the zoo process, just as intent on keeping animals the same. Animals considered difficult to breed at the beginning of the century were producing new mutants of color and pattern by its end, most of them more valuable than their natural ancestors. Many zoo mammals began reproducing regularly, including even gorillas and rhinoceroses, and the breeding of some species had to be curtailed due to the lack of space. These animals still resemble their wild ances- tors externally in keeping with the aim’s of the zoo profession. X:/greenwood/Roots2/WORK/roots.3f 06/04/2007 6:24 AM Page INTRODUCTION xiii There were several reasons for the accelerated reproduction and domestication of wild animals in the twentieth century.