The Effect of Zoo Visitors on the Behaviour and Welfare of Zoo Mammals Alexandra Farrand

392 Pages·2008·5.37 MB·English

The Effect of Zoo Visitors on the Behaviour and
Welfare of Zoo Mammals

Alexandra Farrand

Department of Psychology

University of Stirling

Thesis submitted in fulfilment of the requirements for the degree of
Doctor of Philosophy

October 2007
Contents

Contents page ii
Acknowledgements page x
Conference Papers, Posters, and Publications page xii
Abstract page xiii

Chapter 1 Introduction

1.1. Why Study the Visitor Effect? page 1
1.1.1. Why Not Study the Visitor Attraction Hypothesis? page 2

1.2. How Do Zoo Visitors Affect Captive Animals? page 4

1.3. Defining and Evaluating Environmental Enrichment page 5

1.4. Assessing Animal Welfare page 8

1.5. Visitor Effect Research and the Zoo Environment page 13

1.6. A Note on Research Design and Statistical Techniques page 17

1.7. Introduction to Chapters page 24

Chapter 2 The Effect of Two Visitor-related Variables on Zoo-housed
Mammals

2.1 Introduction page 26

2.2 Visitor Density page 27
2.2.1 Scale page 28
2.2.2 Latency of Effect page 32
2.2.3 Experimental Manipulation page 34
2.2.4 Visitor Presence Studies: Primates page 37
2.2.5 Visitor Presence Studies: Non-primates page 43
2.2.6 Immediate Effect of Exhibit Density Studies: page 43
Primates
2.2.7 Cumulative Effect of Exhibit Density Studies: page 47
Primates
2.2.8 Cumulative Effect of Exhibit Density Studies: page 50
Non-primates
2.2.9 Cumulative Effect of Institutional Density Studies: page 51
Primates

2.3 Visitor Noise page 52
2.3.1 Visitor Noise Studies: Primates page 54
2.3.2 Visitor Noise Studies: Non-primates page 56

2.4 Study Objectives page 57
ii
2.5 A Note on Visitor Behaviour page 57

Study 1: The Immediate Effect of Zoo Visitor Density on the Behaviour of
Primates, Felids, and Ursids at the Toronto Zoo

2.6 Methods page 59

2.7 Procedures page 61

2.8 Statistical Analysis page 63

2.9 Results
2.9.1 Are Visitor Density and Visitor Noise Discrete page 64
Variables?
2.9.2 The Relationship Between Visitor Density page 65
and Behaviour

2.10 Discussion
2.10.1 Visitor Density and Visitor Noise are Discrete page 73
Variables
2.10.2 The Effect of Vicinity Density page 73
2.10.3 Gorillas and Lions Are Not Affected By Visitor page 76
Density

Study 2: The Immediate Effect of Zoo Visitor Density on the Behaviour of
Primates and Felids at the Oakland Zoo

2.11 Methods page 77

2.12 Procedures page79

2.13 Statistical Analysis page 80

2.14 Results
2.14.1 The Relationship Between Visitor Density and page 81
Behaviour

2.15 Discussion
2.15.1 The Effect of Visitor Density on Behaviour page 87

Study 3: Comparing Vicinity and Institutional Scale to Determine if there is a
Preferred Method of Measuring Visitor Density

2.16 Methods page 91

2.17 Procedures page 91

2.18 Statistical Analysis page 91

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2.19 Results
2.19.1 The Relationship Between Institutional Density page 92
and Vicinity Density
2.19.2 The Relationship Between Institutional Density page 92
and Behaviour

2.20 Discussion page 99

Study 4: The Effect of Visitor Noise

2.21 Methods page 100

2.22 Procedures page 100

2.23 Statistical Analysis page 102

2.24 Results page 104

2.25 Discussion page 110

2.26 Conclusion page 113

Chapter 3 Can Visual Barriers Moderate the Visitor Effect in Zoo
Mammals?

3.1 Introduction page 116

3.2 Part 1: Are Camouflage Nets an Effective Method of page 117
Moderating the Visitor Effect?
3.2.1 Previous Research on the Effectiveness of External page 118
Visual Barriers
3.2.2 Visitor Density: A Potential Confounding Variable page 121
Affecting Visual Barrier Experiments

3.3 Research Objectives page 123

3.4 Methods page 124

3.5 Procedures page 125

3.6 Statistical Analysis page 128

3.7 Results
3.7.1 Baseline Activity Budgets page 129
3.7.2 Potential Confounding Variables page 132
3.7.3 Camouflage Nets: Changes in Animal Behaviour page 133
3.7.4 The Relationship Between Visitor Density and Animal page 140
Behaviour in the Camouflage Net Condition
3.7.5 The Relationship Between Visitor Noise and Animal page 149
Behaviour in the Camouflage Net Condition
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3.7.6 Changes in Visitor Behaviour page 157

3.8 Discussion
3.8.1 Visitor Density/Noise and Light Are Not page 158
Confounding Variables
3.8.2 Behavioural Changes Following the Introduction page 158
of the Camouflage Nets
3.8.3 The Effect of Visitor Density in the Camouflage page 162
Condition
3.8.4 The Effect of Visitor Noise in the Camouflage Net page 165
Condition
3.8.5 Visitor Behaviour in the Camouflage Net Condition page 167

3.9 Part II: Privacy Screens: Can Internal Visual Barriers Moderate the
Visitor Effect?

3.10 Introduction page 169
3.10.1 Previous Uses of Internal Visual Barriers page 171

3.11 Research Objectives page 172

3.12 Methods page 173

3.13 Procedures page 173

3.14 Statistical Analysis page 174

3.15 Results
3.15.1 Potential Confounding Variables: Visitor Density page 175
and Visitor Noise
3.15.2 Golden Lion Tamarin Use of the Privacy Screen page 175
3.15.3 Behavioural Changes Following the Installation of the page 176
Privacy Screen
3.15.4 The Relationship Between Golden Lion Tamarin page 178
Behaviour and Visitor Density Following the Installation
of the Privacy Screen
3.15.5 The Relationship Between Golden Lion Tamarin page 180
Behaviour and Visitor Noise Following the Installation
of the Privacy Screen
3.15.6 Visitor Behaviour page 181

3.16 Discussion
3.16.1 Visitor Noise: A Confounding Variable page 181
3.16.2 Behavioural Changes Following the Installation of the page 182
Privacy Screen
3.16.3 The Relationship Between Visitor Density and Behaviour page 183
in the Privacy Screen
3.16.4 The Relationship Between Visitor Noise and Behaviour page 186
in the Privacy Screen
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3.17 Conclusion page 186

Chapter 4: Can A Positive Visitor Effect be Achieved by Providing
Puzzle Feeders to Zoo Visitors and Sumatran Orangutans?

4.1 Introduction page 191
4.1.1 Previous Positive Visitor Effect Research page 192
4.1.2 Selection of Study Species page 195

4.2 Research Objectives page 196

4.3 Methods page 197

4.4 Procedures page 198

4.5 Statistical Analysis page 199

4.6 Results
4.6.1 Potential Confounding Variables: Changes in page 199
Visitor Density and Visitor Noise Between Experimental
Conditions
4.6.2 The Orangutan Feeder Condition page 201
4.6.3 Orangutan-visitor Puzzle Feeder Condition page 203
4.6.4 The Relationship Between Visitor Density and page 205
Orangutan Behaviour in the Experimental Condition
4.6.5 The Relationship Between Visitor Noise and Orangutan page 206
Behaviour in the Experimental Conditions
4.6.6 Visitor Behaviour page 211

4.7 Discussion
4.7.1 Confounding Variables page 211
4.7.2 Behavioural Change in the Orangutan Feeder Condition page 212
4.7.3 The Orangutan-visitor Feeders Condition page 212
4.7.4 Visitor Density Effects in the Experimental Conditions page 214
4.7.5 Visitor Noise in the Experimental Conditions page 214
4.7.6 Visitor Behaviour in the Experimental Conditions page 215

4.8 Conclusion page 216

Chapter 5: The Role of Olfaction in the Visitor Effect

5.1 Introduction page 218
5.1.1 Rationale for Selection of Study Species page 220
5.1.2 Rationale for Selection of Study Scents page 222
5.1.3 Animal Welfare Issues page 226
5.1.4 The Study and Its Objectives page 226

5.2 Research Objectives page 227

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5.3 Methods page 227

5.4 Procedures page 228

5.5 Statistical Analysis page 230

5.6 Results
5.6.1 Baseline Activity Budgets page 232
5.6.2 The Effect of Potential Confounding Variables Between page 234
Conditions: Visitor Density, Temperature,
and Wind Speed
5.6.3 Changes in Animal Behaviour in the Enclosure page 236
Olfactory Condition
5.6.4 Changes in Animal Behaviour in the Smelly page 248
Visitor Condition
5.6.5 The Relationship Between Visitor Density and Animal page 253
Behaviour in the Experimental Conditions

5.7 Discussion
5.7.1 Confounding Variables page 261
5.7.2 Behavioural Responses to Enclosure Olfactory Stimuli page 263
5.7.3 Responses to Scents page 267
5.7.4 Habituation to Olfactory Stimuli page 268
5.7.5 Behavioural Responses to Smelly Zoo Visitors page 269
5.7.6 Visitor Density in the Experimental Conditions page 271

5.8 Conclusion page 274

Chapter 6: The Visitor Effect in Petting Zoo Animals

6.1 Introduction page 277
6.1.1 Previous Petting Zoo Research Findings page 277

6.2 Part I: The Visitor Presence and Density Study page 283

6.3 Research Objectives page 284

6.4 Methods page 285

6.5 Procedures page 287

6.6 Statistical Analysis page 288

6.7 Results
6.7.1 Activity Budgets page 289
6.7.2 Potential Confounding Variables: Visitor Density page 290
and Weather
6.7.3 The Effect of the Presence of Visitors on Pets Farm page 290
Behaviour
6.7.4 Seasonal Effects on On-display Behaviour page 293
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6.7.5 Comparison of Species Interactions with Visitors page 295
6.7.6 The Relationship Between Visitor Density page 296
and Behaviour

6.8 Discussion
6.8.1 Visitor Density and Weather Unlikely Confounding page 301
Variables
6.8.2 The Presence of Visitors Affects Llama and Vietnamese page 301
Pot-bellied Pig Behaviour
6.8.3 Seasonal Visitor Effect in Goats page 302
6.8.4 Species Differences in Interactions with Visitors page 303
6.8.5 Visitor Density Effects page 303

Part II: The Grooming Experiment

6.9 Introduction page 305

6.10 Research Objectives page 311

6.11 Methods page 311

6.12 Procedures page 312

6.13 Statistical Analysis page 313

6.14 Results
6.14.1 Potential Confounding Variable: Visitor Density page 313
6.14.2 The Effect of Visitor Grooming on Animal Behaviour page 314
6.14.3 Response to Visitor Grooming page 315
6.14.4 The Effect of Grooming on Visitor Behaviour page 318

6.15 Discussion page 320

6.16 Conclusion page 323

Chapter 7: Conclusion

7.1 Recommendations for Zoos page 327

7.2 Visitor Density/Noise and Other Audience-related Variables page 331

7.3 Moderating the Negative Visitor Effect page 332

7.4 Facilitating A Positive Visitor Effect page 333

7.5 Primate Bias in Literature and BIAZA Guidelines page 335

7.6 Short-term (Immediate) versus Long-term Studies page 336

7.7 Non-behavioural Measures of the Visitor Effect page 337
viii
7.8 Baseline Welfare Level Determines the Extent of the page 337
Visitor Effect?

7.9 Prevention Rather than Cure? page 339

References page 341

Appendix A page 354

Appendix B page 356

Appendix C page 368

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Acknowledgements

I would like to thank Dr. Hannah M. Buchanan-Smith for her patience
over the years this thesis took shape. I appreciate her compassionate and
constructive criticism, which I hope has vastly improved my understanding and
practice of animal behaviour and welfare research. I am also indebted to Dr.
James Anderson for his initial help in narrowing down the thesis topic, and for
reading the hideously rough and embarrassingly long first chapter I wrote; Dr.
Anderson’s willingness to provide access to his personal library was also
incredibly helpful. Dr. Lois Bassett and Dr. Richard Parnell were very generous
with their libraries when I first arrived at Stirling and saved me hours of reference
hunting. Dr. Jean McKinley did her best to help me avoid irreversible scientific
blunders, and Dr. Kay Farmer served as expert advisor on adapting to
postgraduate life in Stirling.
This thesis would not have been possible without the co-operation of the
zoos, and I am grateful to the Toronto Zoo, Oakland Zoo, Edinburgh Zoo, and
Blair Drummond Safari Park and their employees. In particular, I appreciate all
the extra hard work that Dr. Graham Crawshaw, Charles Guthrie, Elizabeth
Abram, and Gary Gilmour had to undertake to make my research possible. Mark
Jones deserves applause for collecting pilot data with me and helping me sort out
my methodology.
The statistical advice I received from Dr. Amy Plowman, Dr. Graham
Ruxton, Dr. John Todman, and Dr. Pat Dugard was immeasurable. Dr. Jim King,
Dr. Catharine Howie, and Dr. Ranald MacDonald also contributed to my
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