The Welfare of Zoo-housed Chimpanzees (Pan troglodytes) with Special Attention to Auditory Enrichment Emma Katherine Wallace PhD University of York Psychology November 2016 Abstract Modern zoos house millions of wild animals but also aim to conduct animal research, educate visitors about the natural world and support conservation programmes via funding and encouraging wildlife-friendly actions by the public. However, the benefit to conservation efforts and species living in the wild, through fundraising and increasing public awareness, may come at the cost of the animals living within zoos. In this thesis I focussed on the welfare of zoo-housed chimpanzees due to their endangered status and public popularity. I investigated potential social, dietary and visitor related triggers for anxiety-related behaviours (yawning and scratching) and regurgitation and reingestion (R/R). Despite interesting trends, no immediate triggers for these behaviours were found. However, long-term data showed the frequency with which individuals engage in R/R reduced over time when part of a complex group inhabiting an enclosure encouraging natural behaviours and social dynamics. I also examined if music, frequently broadcast to captive chimpanzees, provides any enriching effect on their welfare. Both observational and experimental research suggested that whilst music does not appear to have any obvious positive welfare effects it is equally not detrimental. The final study explored whether public education, one of assumed benefits associated with having animals in zoos, is achieved via ‘Keeper Talks’. They were effective at demonstrating to adult visitors that touchscreens are an effective form of enrichment for chimpanzees but the talks had no significant effect on their knowledge of other issues covered, or any area of knowledge in young people. Further investigation showed that zoo professionals have inaccurate estimates of visitor knowledge and that assessment methods do not always align with educational goals. Overall, the findings in this thesis highlight the importance of research within zoos, which can lead to a better understanding of barriers to good animal welfare, utilisation of only positive welfare interventions and maximisation of educational potential. 2 Table of Contents Abstract ……………………………………………………………………………………………………………………………2 Table of Contents ……………………………………………………………………………………………………………..3 List of Tables …………………………………………………………………………………………………………………….8 List of Figures ………………………………………………………………………………………………………………….11 Dedication ……………………………………………………………………………………………………………………..14 Acknowledgements ……………………………………………………………………………………………………….15 Author’s Declaration ………………………………………………………………………………………………………16 Chapter 1: Modern Zoo Principles …………………………………………………………………………………17 History of Zoos and Captive Animals ……………………………………………………………….17 Modern Zoos ……………………………………………………………………………………………………17 Conclusion ……………………………………………………………………………………………………….20 Chapter 2: The Welfare of Chimpanzees in Captivity ……………………………………………………21 What is Animal Welfare? …………………………………………………………………………………21 Measuring Welfare …………………………………………………………………………………………21 Challenges to welfare in a zoo environment …………………………………………………24 Challenges to welfare of zoo-housed Chimpanzees ………………………………………24 Measures of Poor Welfare in Chimpanzees ……………………………………………………27 How do we Improve Welfare in Zoos?...............................................................27 Social Enrichment ………………………………………………………………………………29 Occupational or Cognitive Enrichment ………………………………………………29 Physical Enrichment ……………………………………………………………………………30 Nutritional Enrichment ……………………………………………………………………….30 Sensory Enrichment ……………………………………………………………………………30 Chimpanzees and Enrichment …………………………………………………………………………31 Conclusion ………………………………………………………………………………………………………32 Thesis Outline and Aims …………………………………………………………………………………32 Chapter 3: Welfare of Zoo-housed Chimpanzees (Pan troglodytes) with special attention to Regurgitation and Reingestion (R/R) ……………………………………………………………………………34 3 Abstract ………………………………………………………………………………………………………….34 Introduction ……………………………………………………………………………………………………35 Aims and Research Questions …………………………………………………………………………37 Methods …………………………………………………………………………………………………………38 Study Site ……………………………………………………………………………………………38 Subjects ………………………………………………………………………………………………39 Study 1: Short-term Data …..……………………………………………………………………………41 Data Collection ……………………………………………………………………………………41 Data Analysis ……………………………………………………………………………………………………42 Statistical Analysis ……………………………………………………………………………….42 Results ………………………………………………………………………………………………………………45 Discussion …………………………………………………………………………………………………………51 Study 2: Long-term Data ……………………………………………………………………………………53 Aims and Research Questions ………………………………………………………………………….53 Methods ……………………………………………………………………………………………………………54 Data Analysis ……………………………………………………………………………………………………55 Statistical Analysis ………………………………………………………………………………56 Results ……………………………………………………………………………………………………………57 Discussion ………………………………………………………………………………………………………62 Conclusions ……………………………………………………………………………………………………64 Chapter 4: Is Music enriching for group-housed captive chimpanzees? - Behavioural Observations …….……………………………………………………………………………………65 Abstract …………………………………………………………………………………………………………65 Introduction ……………………………………………………………………………………………………65 Study 1: Whole Group Observations ..……………………………………………………………67 Aims and Research Questions …………………………………………………………………………67 Methods ……………………………………………………………………………………………………………67 Ethics Statement …………………………………………………………………………………67 Study Site ……………………………………………………………………………………………68 Subjects ………………………………………………………………………………………………68 4 Materials ………………………………………………………………………………………………68 Stimuli …………………………………………………………………………………………………68 Data Collection ……………………………………………………………………………………69 Data Analysis ……………………………………………………………………………………………………71 Statistical Analysis ……………………………………………………………………………….72 Results ……………………………………………………………………………………………………………73 Discussion ………………………………………………………………………………………………………77 Study 2: Individual Observations …………………………………………………………………….78 Aims and Research Questions …………………………………………………………………………78 Methods …………………………………………………………………………………………………………78 Subjects ………………………………………………………………………………………………78 Stimuli …………………………………………………………………………………………………79 Data Collection …………………………………………………………………………………….79 Data Analysis …………………………………………………………………………………………………….80 Statistical Analysis …………………………………………………………………………………80 Results ………………………………………………………………………………………………………………80 Discussion ………………………………………………………………………………………………………….81 Chapter 5: Is Music Enriching for Group-housed Captive Chimpanzees (Pan troglodytes)? - Experimental Investigations ……………………………………………………………………………………………83 Abstract …………………………………………………………………………………………………………….83 Introduction ………………………………………………………………………………………………………83 Study 1: National Centre for Chimpanzee Care ..………………………………………………84 Aims and Research Questions ……………………………………………………………………………84 Methods ……………………………………………………………………………………………………………84 Ethics Statement …………………………………………………………………………………84 Study Site ………………………………………………………………………………………………85 Subjects …………………………………………………………………………………………………85 Apparatus and procedure.……………………………………………………………………85 Data Analysis ……………………………………………………………………………………………………86 Results ………………………………………………………………………………………………………………87 5 Discussion ………………………………………………………………………………………………………..90 Study 2: Edinburgh Zoo ……………………………………………………………………………………90 Aims and Research Questions …………………………………………………………………………90 Methods ………………………………………………………………………………………………………….91 Study Site ……………………………………………………………………………………………91 Apparatus ………………………..…………………………………………………………………91 Subjects ………………………………………………………………………………………………92 General procedure.…………………………………………………………………………….92 Training ………………………………………………………………………………………………93 Individual testing …………………………………………………………………………………94 Group testing ………………………………………………………………………………………95 Observational Data Collection .……………………………………………………………96 Data Analysis …………………………………………………………………………………………………….96 Results ………………………………………………………………………………………………………………98 Discussion …………………………………………………………………………………………………………103 General Discussion ……………………………………………………………………………………………105 Chapter 6: Are ‘Keeper Talks’ effective at transmitting educational messages about environmental enrichment within zoos? ……………………………………………………………………….107 Abstract ……………………………………………………………………………………………………………107 Introduction ……………………………………………………………………………………………………..108 Study 1: Zoo Visitor Knowledge ……………………...………………………………………………..111 Aims and Research Questions …………………………………………………………………………..111 Methods …………………………………………………………………………………………………………..111 Ethics Statement ………………………………………………………………………………….111 Study Site …………………………………………………………………………………………….112 Chimpanzee Keeper Talk ..……………………………………………………………………112 Participants ………………………………………………………………………………………….113 Questionnaire …..………………………………………………………………………………….114 Data Analysis …………………………………………………………………………………………………….115 Statistical Analysis ………………………………………………………………………………..121 6 Results ………………………………………………………………………………………………………………121 Discussion …………………………………………………………………………………………………………131 Study 2: Zoo Professionals ………………………………………………………………………………..135 Aims and Research Questions …………………………………………………………………………..135 Methods ……………………………………………………………………………………………………………135 Ethics Statement ………………………………………………………………………………….135 Questionnaire Participants …………………………………………………………………..135 Interview Participants ………………………………………………………………………….136 Questionnaire Methodology ………………………………………………………………..136 Interview Methodology …………………………………………………………………..…..136 Data Analysis