Bird Ecology and Conservation A Handbook of Techniques

Techniques in Ecology and Conservation Series Series Editor: William J. Sutherland This page intentionally left blank Bird Ecology and Conservation A Handbook of Techniques William J. Sutherland, Ian Newton, and Rhys E. Green 1 Great Clarendon Street,Oxford OX2 6DP Oxford University Press is a department ofthe University ofOxford. It furthers the University’s objective ofexcellence in research,scholarship, and education by publishing worldwide in Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With offices in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan South Korea Poland Portugal Singapore Switzerland Thailand Turkey Ukraine Vietnam Published in the United States by Oxford University Press Inc.,New York © Oxford University Press 2004 The moral rights ofthe author have been asserted Database right Oxford University Press (maker) First published 2004 Reprinted 2005 All rights reserved.No part ofthis publication may be reproduced, stored in a retrieval system,or transmitted,in any form or by any means, without the prior permission in writing ofOxford University Press, or as expressly permitted by law,or under terms agreed with the appropriate reprographics rights organization.Enquiries concerning reproduction outside the scope ofthe above should be sent to the Rights Department, Oxford University Press,at the address above. You must not circulate this book in any other binding or cover and you must impose this same condition on any acquirer. A catalogue record for this title is available from the British Library Library ofCongress Cataloging in Publication Data (Data available) ISBN 0 19 852085 9 (Hbk) ISBN 0 19 852086 7 (Pbk) 10 9 8 7 6 5 4 3 2 Typeset by Newgen Imaging Systems (P) Ltd.,Chennai,India Printed in Great Britain on acid-free paper by Biddles Ltd.,King’s Lynn,Norfolk Preface We decided to produce this book, as we were aware of the dif?culties of providing information on the methods available to ?eld ornithologists or conservationists. We also believed that the dif?culties of accessing methodology were hindering thedevelopment of the science and the enactment of effective conservation. Thus when we were asked how to conduct a project involving say foraging behavior or breeding biology, we could point out a few papers and describe some methods, but had no source that would outline the major techniques in a comprehen- sive manner. Our target audiences are young biologists starting a research or conservation project involving birds, or more established researchers who may be familiar with some but not all of the more useful methods available. This is the ?rst in an intended series of books devoted to methods in ecology and conservation. Each book will either treat a taxonomic group, as this book does, or a broad subject area. We also thank the authors for their efforts and, not least, for putting up with our various idiosyncrasies. We are donating two hundred copies of this book to ornithologists and libraries outside Western Europe, North America, Australia, New Zealand and Japan who would otherwise be unable to obtain a copy. We will donate another hundred with each reprinting. We thank Ian Sherman at OUP for organizing this, the British Ecological Society for funding the postage and the nhbs.com bookstore for coordinating the distribution. Suggestions of recipients for copies can be made at the Gratis books website http://www.nhbs.com/gratis-books. We thank Ian Sherman of Oxford University Press for his enthusiasm and ef?ciency. Working with him has been a pleasure. William J. Sutherland, Ian Newton and Rhys E. Green This page intentionally left blank Contents List of Contributors xvii 1. Bird diversity survey methods 1 Colin J. Bibby 1.1 Introduction 1 1.2 Designing the fieldwork 3 1.3 Finding the birds 4 1.4 Standardizing the effort by time and space 6 1.5 Standardizing the effort by McKinnon’s list method 7 1.6 Atlas studies 8 1.7 Estimating species richness 10 1.8 Conclusion 11 2. Bird census and survey techniques 17 Richard D. Gregory, David W. Gibbons, and Paul F. Donald 2.1 Introduction 17 2.1.1 What are bird surveys and why do we need them? 17 2.1.2 What is monitoring and why do we need it? 18 2.1.3 Useful sources of information 19 2.1.4 Begin at the beginning 20 2.1.5 Population size or index? 21 2.1.6 Survey boundaries 21 2.1.7 Census or sample? 22 2.1.8 Sampling strategy 23 2.1.9 Sampling unit 23 2.1.10 Field methods 23 2.1.11 Accuracy, precision, and bias 23 2.2 Sampling strategies 27 2.2.1 How many sampling units? 27 2.2.2 Which sampling units to count? 27 2.2.3 Using stratification 29 2.3 Field methods 35 2.3.1 Mapping 36 2.3.2 Transects 38 2.3.3 Line transects 39 viii | Contents 2.3.4 Point transects 40 2.3.5 Rules for recording birds in the field 41 2.3.6 Choosing between line and point transects 41 2.3.7 Detection probabilities 42 2.3.8 Colonial birds 44 2.3.9 Counting roosts and flocks 45 2.3.10 Counting leks 46 2.3.11 Counting migrants 46 2.3.12 Capture techniques 47 2.3.13 Tape playback 50 2.3.14 Vocal individuality 51 2.4 Conclusions 52 3. Breeding biology 57 Rhys E. Green 3.1 Introduction 57 3.2 Choosing study areas 58 3.3 Measuring the success of individual breeding attempts 58 3.3.1 Finding and selecting nests 58 3.3.2 Recording the stage of a breeding attempt when it is located 60 3.3.3 Precautions to take so that nests can be relocated for checking 61 3.3.4 Nest checking 62 3.3.5 Determination of chick survival for species with precocial young 64 3.3.6 Estimation of nest success from nest check data 66 3.4 Determination of the proximate causes of breeding failure 67 3.4.1 Signs left at the nest 67 3.4.2 Wax or plasticine eggs in the nests of wild birds 68 3.4.3 Cameras 69 3.4.4 Temperature loggers 70 3.5 Using artificial nests to measure nest success and causes of failure 71 3.6 Measuring annual productivity 72 3.6.1 Why measure annual productivity? 72 3.6.2 Productivity from counts after the breeding season 74 3.6.3 Productivity from captures after the breeding season 74 3.6.4 Intensive studies of breeding 75 3.6.5 Indices of productivity from surveys during the breeding season 76 3.6.6 Use of simulation models 76 3.7 Timing of breeding 76 3.8 Measurements of eggs and chicks 78 3.9 Proximate and ultimate causes of breeding failure 79 Contents | ix 3.10 Value of experiments to disentangle ultimate and proximate causes of breeding failure 79 4. Birds in the hand 85 Andrew Gosler 4.1 Introduction 85 4.2 Welfare, ethical, and legislative issues 86 4.3 Catching the birds 87 4.3.1 The breeding season 89 4.3.2 Cage traps 90 4.3.3 Spring traps 90 4.3.4 A couple of nestbox traps 91 4.3.5 Noose-carpet traps 91 4.3.6 Mist-nets 92 4.3.7 Clap-nets and whoosh-nets 94 4.3.8 Canon-nets 94 4.3.9 Capture by hand 94 4.4 Individual marking 95 4.5 Notes on bird handling 99 4.6 The bird at close quarters 100 4.6.1 Age and molt 100 4.6.2 Sex 102 4.6.3 Weight 103 4.6.4 Color, for example, UV reflectance 103 4.7 Size 104 4.7.1 Body size 104 4.7.2 Wing 104 4.7.3 Tail 106 4.7.4 Tarsus 106 4.7.5 Tarsus-and-toe 108 4.7.6 Bill 108 4.7.7 Total-head 110 4.7.8 Claw, eye-ring, and other measures 110 4.8 Condition 110 4.8.1 Asymmetry 110 4.8.2 Relative mass 111 4.8.3 Fat reserves 111 4.8.4 Muscle protein 113 4.8.5 Physiological measures 113 4.8.6 Molt and plumage 113 4.8.7 Parasites 114 4.9 Biopsy 115