Institut für Neurobiologie Universität Ulm Social relationships in zoo-living bonobos, Pan paniscus Dissertation zur Erlangung des Doktorgrades Dr. rer. nat. der Fakultät für Naturwissenschaften der Universität Ulm vorgelegt von Stefanie Eva Kießling aus Augsburg Ulm 2008 Amtierender Dekan: Prof. Dr. Klaus-Dieter Spindler Erster Gutachter: Prof. Dr. Günter Ehret Zweiter Gutachter: Prof. Dr. Harald Wolf Tag der mündlichen Prüfung: 10.07.2008 Die Arbeit wurde finanziell gefördert durch ein Promotionsstipendium des Evangelischen Studienwerkes e.V. Villigst. Front cover: Bonobo female Bonnie, Cologne Zoo (drawing by Dorothee Claßen) Impressions of the bonobo group in Frankfurt (drawing by Alexander Rebik, 2003) Table of contents 1. Introduction .......................................................................................................................... 1 1.1 Social relationships .......................................................................................................... 1 1.2 Primate social systems ..................................................................................................... 2 1.3 Fission-fusion societies ....................................................................................................4 1.4 The bonobo, Pan paniscus ............................................................................................... 6 Distribution and feeding ecology ....................................................................................... 6 Grouping patterns and social behaviour............................................................................. 7 1.5 Aim of the study............................................................................................................. 14 2. Animals and Methods ........................................................................................................ 16 2.1 Animals and keeping conditions .................................................................................... 16 a) Frankfurt....................................................................................................................... 16 b) Planckendael ................................................................................................................ 17 c) Cologne ........................................................................................................................ 18 2.2 Data collection................................................................................................................ 19 2.3 Ethogram ........................................................................................................................ 20 2.4 Data analysis .................................................................................................................. 22 2.5 Statistics ......................................................................................................................... 25 3. Results ................................................................................................................................. 26 3.1 Interactive behaviour...................................................................................................... 26 3.1.1 Categories of interactive behaviour......................................................................... 29 3.1.2 Age-sex class specific patterns................................................................................ 31 Interactive behaviour.................................................................................................... 32 a) Frankfurt............................................................................................................... 32 b) Planckendael ........................................................................................................ 32 c) Cologne ................................................................................................................ 33 Physical contact............................................................................................................ 34 a) Frankfurt............................................................................................................... 34 Infants disengagement.......................................................................................... 35 b) Planckendael ........................................................................................................ 36 c) Cologne ................................................................................................................ 36 Overall picture.............................................................................................................. 37 3.1.3 Specific aspects of the social network..................................................................... 39 Agonistic behaviours.................................................................................................... 39 a) Frankfurt............................................................................................................... 39 b) Planckendael ........................................................................................................ 40 c) Cologne ................................................................................................................ 42 Allogrooming behaviour .............................................................................................. 43 a) Frankfurt............................................................................................................... 43 b) Planckendael ........................................................................................................ 45 c) Cologne ................................................................................................................ 47 Sexual contacts............................................................................................................. 49 a) Frankfurt............................................................................................................... 49 b) Planckendael ........................................................................................................ 50 c) Cologne ................................................................................................................ 51 Overall picture.............................................................................................................. 51 3.2 Spatial behaviour............................................................................................................ 55 3.2.1 Categories of spatial proximity ............................................................................... 56 3.2.2 Individual differences.............................................................................................. 57 I Table of contents a) Frankfurt................................................................................................................... 57 b) Planckendael ............................................................................................................ 58 c) Cologne .................................................................................................................... 59 Overall picture.............................................................................................................. 60 3.2.3 Hierarchical cluster analysis.................................................................................... 61 3.3 Activity budget............................................................................................................... 63 3.4 Artificial fission-fusion conditions................................................................................. 65 4. Discussion............................................................................................................................ 71 4.1 Methodological restrictions and effects of captivity...................................................... 71 4.2 Results ............................................................................................................................ 73 4.2.1 Patterns of social relationships................................................................................ 73 4.2.2 Comparison of keeping conditions.......................................................................... 79 4.2.3 Influence of artificial fission-fusion conditions ...................................................... 80 4.3 General conclusions ....................................................................................................... 84 5. Summary............................................................................................................................. 87 6. Zusammenfassung..............................................................................................................89 7. References ........................................................................................................................... 91 8. Appendix ........................................................................................................................... 100 Danksagung........................................................................................................................... 105 Curriculum vitae .................................................................................................................. 106 Eidesstattliche Erklärung...................................................................................................