Bird Ecology and Conservation: a Handbook of Techniques

Formerly CIP.

Contents


List of Contributors xvii
1. . Bird diversity survey methods 1
Colin}.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 2 Sampling strategies 27
2.2.1 1 How many sampling units? 27
2.2.2 Which sampling units tocount? 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 transec ts 39

viii I 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 I nt roduction 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 nest s 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 [stimation of nest success from nest check data 66
3.4 Determina tion 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 prod uctivity 72
3.6.1 Whymeasure 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 I IX
3.10 Value of experiments to disentangle ultimate and
proximate causes of breeding failure 79
4. Birds in the hand 85
Andrew Gosier
4.1 Introduction 85
4.2 Welfare,ethical,and legislative issues 86
4.3 3 Catching the birds 87
4.3.l 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-net s and whoosh-nets 94
4.3.8 Canon-nets 94
4.3.9 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.l Ag e and molt 100
4.6.2 S ex 102
4.6.3 Weight 103
4.6.4 Color.for example . UV reflectance 103
4.7 Size 104
4.7. l 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.l Asymmetry 110
4.8.2 Relative mass 111
4.8.3 Fat reserves 1ll
4.8.4 M uscle prot ein 113
4.8.5 5 Physiological measures 113
4.8.6 M olt and plumag e 113
4.8.7 Parasites 114
4.9 Biopsy 115

x \ Contents

5. Estimating survival and movement
James D. Nichols, William L. Kendall, and Michael C. Runge
5.1 I ntroduction
5.2 Tag type and subsequent encounters
5.3 Survival rates
5.3.1 Radio-telemetry
5.3.2 Capture-recapture/ resighting
5.3.3 Band recovery
5.4 Movement
5.4.1 Radio-telemetry
5.4.2 Capture-reca pture/resighting
5.4.3 Band recovery
5.5 Summary and general recommendations



119

119
120
120
120
124
127
129
129
131
133
134



6. Radio-tagging
Robert Kenward
6.1 Introduct ion
6.2 Choice of techniques
6.2.1 Constraints on radio tagging
6.2.2 Applications and advantages
6.2.3 Considerations for tag attachment
6.3 Forward planning
6.3.1 Equipment
6.3.2 M obile tracking
6.3.3 Software
6.4 Approaches
6.4.1 Pilot studies
6.4.2 Recording locations
6.4.3 Using location data
6.4.4 Demography
6.5 The future

141

141
142
142
143
145
148
148
150
150
151
151
152
154
155
156



7. Migration
Susanne Akesson and Anders Hedenstrom
7.1 Introduction
7.2 Migration systems
7.2.1 M ark-recapture
7.2.2 M orphology
7.2.3 Genetic markers
7.2.4 Stable isotopes
7.3 Migration behavior and strategies
7.3.1 Counting and observing migrants

161

161
161
162
162
163
163
165
165



7.3.2 Tracking migrants
7.3.3 Remote sensing: infrared device
7.3.4 Remote sensing: radar
7.3.5 Stopover
7.4 Physiology of migration
7.4.1 Body composition
7.4.2 Energetics
7.4.3 Endocrinology
7.5 Flightin wind tunnels
7.6 Orientation and navigation
7.6.1 Emlen funnels
7.6.2 M anipulating sensory input
7.6.3 Displacement experiments
7.6.4 Selection experime nts
7.6.5 Circular statistics
7.7 Modeling migration
7.8 Concluding remarks

8. Information from dead and dying birds
John E. Cooper
8.1 Introduction
8.1.1 Terminology-definitions and explanation
8.1.2 M ethodology -an overview of techniques
8.2 The postmortem examination
8.3 Health and safety
8.4 Postmortem examinations (necropsies)
8.5 Laboratory investigations
8.6 Interpretation of findings
8.7 Legal aspects 8.8 Conclusions

9. Tech niques in physiology and genetics
Alistair Dawson

Contents I xi
166
167
167
169
169
169
170
171
171
172
172
172
173
174
174
175
176

179

179
181
181
183
185
187
194
199
201
203

211

9.1 Introduction 211
9.2 Sampling techniques 211
9.2.1 Ethical considerations 211
9.2.2 Legal considerations -catcl1ing wild birdsfor research 212
9.2.3 Legal considerations -scientific experiments on birds 213
9.2.4 Housing and husbandry 216
9.2.5 Blood sampling 217
9.2.6 Administration of substances 218
9.2.7 Anestl1esia 219




xii I Contents







9.2.8 Implant s 219
9.2.9 Laparotomy 220

9.3 Ecotoxicology 221
9.4 Endocrinology 222
9.5 Energetics 224
9.6 Molecular genetics 225
10. Diet and foraging behavior 233
William). Sutherland
10.l Introduction 233
10.2 Diet composition 233
10.2.l Direct observation 233
10.2.2 Nest observations 235
10.2.3 Remains and signs 235
10.2.4 Dropping analysis 236
10.2.5 Pellet analysis 239
10.2.6 Stomach analysis 239
10.2.7 Direct observations of crop 240
10.2.8 Regurgitates 240
10.2.9 Cafeteria experiments 240
10.2.10 Morphology 240
10.2.11 Neck ligatures 241
10.2.12 Emetics and flushing 241
10.2.13 Isotope differences between habitats 241
10.3 Determi ning prey size 242
10.3.1 Direct observation of prey size 242
10.3.2 Determining size from prey remains 242
10.3.3 Determining prey size from regurgitates 242
10.3.4 M easuring fragments in pellets, droppings. or stomach 242
10.4 Prey quality 243
10.4.1 Energy content 243
10.4.2 Prey digestibility 244
10.5 Foraging behavior 244
10.5.1 Time budgets 244
10.5.2 Time spent feeding per day 245
10.5.3 Night observations 245
10.5.4 Handling time 246
10.5.5 Intake rate and the functional response 246
10.5.6 Interference 247
10.5.7 Depletion 247
10.5.8 Prey a vailability 248
10.5.9 Exclosures 248
10.5.10 M ate provisioning and brood provisioning rates 249










11. Habitat assessment
Contents I xiii
251
William). Sutherland and Rhys E. Green
11.1 Introduction 251
11 .1.1 Habitat associations 251
11.1.2 Documenting changes over time 252
11 .2 Protocols 252
11 .3 Physical environment 254
11.3.1 Temperature and thermoregulation 254
11.3.2 Rainfall and soil wetness 255
11.3.3 Slope. aspect. elevation. and topography 255
11.3.4 'Tfpe. chemistry. and penetrability of soils 255
11.3.5 Waterchemistry 256
11.4 Vegetation 257
11.4.1 M apping of broad habitat types 257
11.4.2 Species composition of vegetation 258
11 .4.3 Vegetation architecture 258
11 .5 Quantifying habitat selection 260
11.5.1 Comparing the relative abundance of birds or records of tracked birds in each of several habitats with the relative
areas of the habitats available 260
11.5.2 Relating numbers or densities of individuals or records of tracked birds in spatial units to the habitat composition
of those units 262
11 .5.3 Comparison of habitat at places used by birds with that at places that are representative of the study area or
known tobe unused 262
11 .6 Food abundance and availability 263
11.7 Predator abundance 265
11 .8 Disturba nce 266
12. Conservation management of endangered birds 269
Carl C.Jones
12.1 Introduction 269
12.2 Process in the restoration of endangered species 269
12.2.1 Step one: knowyour species 270
12.2.2 Step two: diagnose causes of population decline
and test remedial action 270
12.2.3 Stage three: intensive management 271
12.2.4 Stagefour: population management 271
12.2.5 Stage five: monitoring 271
12.3 Broad population management approaches 272
12.3.1 Supplemental feeding 273
12.3.2 Enhancing nest-sites and the provision of nest-boxes 274

xiv I Contents

12.3.3 Disease control
12.3.4 Predator control

277
278

12.4 Intensive management of focal pairs
12.4.1 Close guarding and monitoring of nest s
12.4.2 Clutch and brood manipulations
12.5 Reintroduction and tra nslocations
12.5.1 Reintroduction
12.5.2 Translocations
12.6 Supportive management for bird restoration projects
12.6.1 Role of captive facilities
12.6.2 Model or surrogate species
12.6.3 Artificial incubation and hand-rearing
12.7 Integra ted management
12.8 Discussion

280
280
281
288
288
290
291
291
292
292
293
293



13. Exploitation
Michael C. Runge, William L. Kendall, and James D. Nichols
13.1 I ntroduction: assessment of exploitation
13.1.1 Taking a conservative approach
13.1.2 Minimum estimates of population size
13.1.3 Estimates of harvest levels

303

303
303
303
304

13.1.4 Population models and associated param eters 304
13.1.5 The use of trend s 304

13.2 Theoretical basis for sustainable exploitation 305
13.2.1 Logistic growth model with perfect information 305
13.2.2 Incorporating uncertainty: potential biological removal
307
13.2.3 A note about other methods of assessing sustainability 309
13.3 Harvest control and managemen t objectives 310
13.3.1 Harvest management strategies 310
13.3.2 H arvest management objectives 311
13.4 Assessing harvest levels 312
13.4.1 Total harvest (H ) versus harvest rate (h) 3l2
13.4.2 Harvest estimation when harvest is legal and observable 312
13.4.3 Harvest estimation when harvest is illegal 314
13.4.4 Measuring harvest rate 315
13.5 Assessing population size 316
13.5.1 Overview 316
13.5.2 Coping with uncertainty 316

13.6 Assessing population dynamics
13.6.1 M aximum growth rate (rmoJ
13.6.2 Other asp ects of density depend ence
13.6.3 Other driving forces
13.6.4 M odel structure

317
317
318
320
320





13.7 Addressing uncertainty Contents I xv
322
13.7.1 M otivation 322
13.7.2 Management experiments 322
13.7.3 Ada ptive management 323
14. Habitat management 329
M alcolm Ausden
14.1 I ntroduction 329
14.2 Deciding wha t to do 330
14.3 Monitoring 333
14.4 General principles of managing habitats for birds 334
14.4.1 Factors influencing habitat use by birds 334
14.4.2 Taking account of the requirement s of non-bird species 335
14.4.3 Controlling unwanted plants 336
14.4.4 Taking account of predicted climate change 337
14.5 Managing grasslands 337
14.5.1 Introduction 337
14.5.2 Effects of cutting and burning on sward condition 338
14.5.3 Effects of grazing on sward condition 339
14.5.4 Minimizing nest and chick loss during management 341
14.5.5 Using fertilizer 342
14.5.6 Hydrology of wet grasslands 343
14.6 Managing dwarf shrub habita ts 344
14.7 Managing forests and scrub 345
14.7.1 Introduction 345
14.7.2 Grazing and browsing 347
14.7.3 Burning 348
14.7.4 Planting and harvesting regimes 349
14.7.5 Thinning and creating gaps 350
14.7.6 Increasing the quantity of dead wood 351
14.8 Ma naging deep water 351
14.9 Ma naging wetlands
14.9.1 M anipulating the pro portions of open water. 352
ruderal vegetation. and swamp 352
14.9.2 Increasing food abundancefor birds in shallow freshwater 353
14.9.3 Increasing food abundance for birds in shallow brackish
and saline water 355
14.9.4 Increasing accessibility of food for birds in shallow water 356
14.9.5 Providing islands and raft s 357
14.9.6 M anaging reedbeds 357
14.9.7 Scrub 360
14.9.8 Wet woodlands 360
14.10 Managing intertidal habitats 360
14.11 Managing arable land and hedgerows 361