UNIVERSITE DE STRASBOURG ECOLE DOCTORALE DES SCIENCES DE LA VIE ET DE LA SANTE IPHC, Département Écologie, Physiologie et Éthologie THÈSE Présentée par: Palmyre BOUCHERIE Soutenue le: 23 September 2016, Pour obtenir le grade de : Docteur de l’Université de Strasbourg Layers of social organisation in rooks, a monogamous bird species THÈSE dirigée par: Dr. Valérie DUFOUR Chargée de recherche HDR, CNRS, Université de Strasbourg RAPPORTEURS : Pr. Thomas BUGNYAR Professeur, Université de Vienne Dr. Claudia WASCHER Lecturer, Université Anglia Ruskin EXAMINATEUR : Dr. Bernard THIERRY Directeur de recherche, CNRS, Université de Strasbourg A mon grand-père, toujours avide d’apprendre. TABLE OF CONTENTS ACKNOWLEDGMENTS ........................................................................................................................................... i PUBLICATIONS ...................................................................................................................................................... iv COMMUNICATIONS ...............................................................................................................................................v LIST OF TABLES ..................................................................................................................................................... vi LIST OF FIGURES AND PICTURES ........................................................................................................................... ix INTRODUCTION ........................................................................................................................ 1 1. LIVING IN GROUPS ........................................................................................................................................... 3 1.1. Competition and cooperation: costs and benefits of group living ..................................................... 3 1.2. From simple aggregations to sociality .............................................................................................. 5 1.3. Role of kinship and reciprocity in cooperative relationships ............................................................. 7 2. SOCIAL ORGANISATIONS AND SOCIAL STRUCTURE ................................................................................................... 9 2.1. Defining a species’ social organisation .............................................................................................. 9 2.2. Levels of social structure ................................................................................................................. 10 2.3. Affiliative relationships and associated structures .......................................................................... 12 2.4. Dominance relationships and social hierarchy ................................................................................ 14 2.5. Group constraints on relationships ................................................................................................. 16 2.5.1 Relatedness ....................................................................................................................................................... 16 2.5.2. Mating system: the case of monogamy ........................................................................................................... 16 2.5.3. Group composition .......................................................................................................................................... 18 2.6. Multi-level social organisations ....................................................................................................... 18 2.7. Spatio-temporal cohesion, dynamics of social structures ............................................................... 19 2.8. Link between advanced cognition and complex sociality ................................................................ 20 2.8.1 Cognition and sociality in mammalian and avian species ................................................................................. 20 2.8.2 How individuals do picture the relationship? ................................................................................................... 22 3. INTER AND INTRA-SPECIFIC VARIATIONS OF SOCIAL ORGANISATIONS......................................................................... 23 3.1. External constraints ......................................................................................................................... 23 3.1.1 Inter-specific variability ..................................................................................................................................... 23 3.1.2 Intraspecific variability ...................................................................................................................................... 24 3.2. Internal constraints ......................................................................................................................... 25 4. THE STUDY OF SOCIAL RELATIONSHIPS AND SOCIAL STRUCTURE IN BIRDS ................................................................... 27 4.1. Diversity of birds’ social organisations and collective behaviours................................................... 28 4.2. Group living in birds: comments on coloniality ............................................................................... 29 4.3. Bird cognition and social complexity ............................................................................................... 30 4.4. Rooks’ social-ecology: Pair bonding and colonial living .................................................................. 31 5. AIM OF THIS THESIS ....................................................................................................................................... 34 GENERAL METHODS .............................................................................................................. 35 1. SOME INFORMATION ABOUT ROOKS (CORVUS FRUGILEGUS) .................................................................................. 36 1.1. General information ........................................................................................................................ 36 1.2. Reproduction ................................................................................................................................... 37 2. METHODS ................................................................................................................................................... 39 2.1. Subjects ........................................................................................................................................... 39 2.2. Housing conditions .......................................................................................................................... 42 2.3. Observation procedure and data collection .................................................................................... 43 2.4. Ethogram ......................................................................................................................................... 44 2.5. Sociality index .................................................................................................................................. 46 CHAPTER 3 ............................................................................................................................ 47 CHAPTER 4 ............................................................................................................................ 74 CHAPTER 5 .......................................................................................................................... 101 CHAPTER 6 .......................................................................................................................... 127 DISCUSSION ......................................................................................................................... 157 1. BEING LONG-TERM MONOGAMOUS IN A SOCIAL GROUP ...................................................................................... 160 1.1. Strength of the monogamous pair bond ....................................................................................... 160 1.2. Secondary affiliations in a socially monogamous species ............................................................. 162 1.3. Impact of secondary affiliations on the monogamous pair bond ................................................. 164 1.4. Same-sex relationships .................................................................................................................. 166 1.5. Variation and stability of pairs and secondary affiliations: comments on the notion of scale ..... 168 2. INVESTIGATING ROOKS’ SOCIAL STRUCTURE ........................................................................................................... 169 1.6. The role of pairs and solitary individuals in rooks’ structure ......................................................... 169 1.7. Robustness of social patterns ........................................................................................................ 172 1.8. Integration of new group members .............................................................................................. 172 2. WHAT ABOUT DOMINANCE RELATIONSHIPS IN ROOKS? ....................................................................................... 174 2.1. Linearity and dominance relationships ........................................................................................