UNIVERSITY OF DERBY A Comparison of Methods of Quantifying and Assessing the Behaviour and Welfare of Bornean Orangutans (Pongo pygmaeus): a Case Study at Twycross Zoo Ruth Helen Bentley Doctor of Philosophy October 2017 Sensitivity: Confidential THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK 2 Sensitivity: Confidential Thesis contents Thesis Contents ....................................................................................................................................... 3 Figures and Tables .................................................................................................................................. 8 Abbreviations used in the thesis............................................................................................................ 12 Preface .................................................................................................................................................. 13 Abstract ................................................................................................................................................. 14 Acknowledgements ............................................................................................................................... 16 1 Chapter ONE: Introduction to the Thesis...................................................................................... 19 1.1 Chapter overview ...................................................................................................................... 19 1.2 Zoos, their roles and responsibilities ......................................................................................... 20 1.2.1 Origins of the modern zoo and the associated legislation ..................................................... 20 1.3 Animal welfare in captivity....................................................................................................... 22 1.3.1 The biological response to stress .......................................................................................... 23 1.3.2 Abnormal and stereotypic behaviours ................................................................................... 24 1.4 Enrichment for captive animals ................................................................................................ 26 1.4.1 Categories of enrichment for captive animals, focussing on use with captive primates ....... 29 1.5 Orangutans ................................................................................................................................ 32 1.5.1 The taxonomy and distribution of the orangutan genus (Pongo spp.) .................................. 32 1.5.2 The morphology of orangutans and their adaptations to the environment ............................ 34 1.5.3 The habitat of wild orangutans .............................................................................................. 36 1.5.4 The dietary needs of wild orangutans ................................................................................... 36 1.5.5 Behavioural ecology of wild orangutans............................................................................... 38 1.5.6 Threats to wild orangutan populations .................................................................................. 40 1.5.7 Orangutan conservation ........................................................................................................ 44 1.6 Research rationale ..................................................................................................................... 47 1.7 Research aims and objectives ................................................................................................... 48 1.7.1 Primary research aims and supporting objectives ................................................................. 48 1.7.2 Thesis structure ..................................................................................................................... 49 2 Chapter TWO: Systematic Review of Research on the Effects of Enrichment on the Welfare of Apes, and Recommendations for the Future ......................................................................................... 52 2.1 Chapter overview ...................................................................................................................... 52 2.2 Introduction ............................................................................................................................... 52 2.3 Methodology ............................................................................................................................. 55 2.3.1 Inclusion criteria for published literature .............................................................................. 55 2.3.2 Reviewing the literature ........................................................................................................ 56 2.4 Results ....................................................................................................................................... 59 2.4.1 Year of publication ............................................................................................................... 59 2.4.2 Country of origin ................................................................................................................... 61 2.4.3 Type of housing and ape subjects ......................................................................................... 62 2.4.4 Single- or multi-genus ........................................................................................................... 62 2.4.5 Research aim ......................................................................................................................... 63 2.4.6 Enrichment category ............................................................................................................. 64 2.4.7 Number of subjects ............................................................................................................... 65 3 Sensitivity: Confidential 2.4.8 Life stage of subjects ............................................................................................................ 66 2.4.9 Sampling and recording method ........................................................................................... 66 2.4.10 Temporal length of study .................................................................................................. 67 2.4.11 Experimental design .......................................................................................................... 67 2.5 Discussion ................................................................................................................................. 67 2.5.1 Year of publication ............................................................................................................... 67 2.5.2 Country of origin ................................................................................................................... 68 2.5.3 Type of housing and ape subjects ......................................................................................... 69 2.5.4 Single- or multi-genus ........................................................................................................... 71 2.5.5 Research aim ......................................................................................................................... 73 2.5.6 Enrichment category ............................................................................................................. 74 2.5.7 Number of subjects ............................................................................................................... 75 2.5.8 Life stage of subjects ............................................................................................................ 76 2.5.9 Sampling and recording method ........................................................................................... 77 2.5.10 Temporal length of study .................................................................................................. 79 2.5.11 Experimental design .......................................................................................................... 80 2.6 Conclusion ................................................................................................................................ 81 3 Chapter THREE: Behavioural Observations to Understand the Impact of an Enrichment Programme on the Behaviour of Captive Bornean Orangutans (Pongo pygmaeus) ............................. 83 3.1 Chapter overview ...................................................................................................................... 83 3.2 Introduction ............................................................................................................................... 83 3.3 Methodology ............................................................................................................................. 85 3.3.1 Subjects and housing ............................................................................................................. 85 3.3.2 Husbandry routine ................................................................................................................. 85 3.3.3 Enrichment treatments .......................................................................................................... 85 3.3.4 Behavioural observations .....................................................................................................