Linking behaviour and physiology of female bonobos (Pan paniscus) [Elektronische Ressource] / vorgelegt von Karin Reichert

Linking behaviour and physiology
of female bonobos (Pan paniscus)












Dissertation

zur Erlangung des Doktorgrades
der Fakultät für Biologie, Chemie und Geowissenschaften
der Universität Bayreuth





vorgelegt von

Karin Reichert
aus Augsburg

Bayreuth 2005
Die vorliegende Arbeit wurde vom Oktober 1996 bis Dezember 2001 unter der Anleitung
von Prof. Dr. Dietrich von Holst und Dr. Gottfried Hohmann am Max-Plack Instutut für
Verhaltensphysiologie in Sewiesen in der Abteilung von Prof. Dr. Wolfgang Wickler und
am Max-Plack-Institut für evolutionäre Anthropologie in Leizig in der Abteilung von Prof.
Dr. Christophe Boesch angefertigt.



Vollständiger Abdruck der von der Fakultät für Biologie, Chemie und Geowissenschaften
der Universität Bayreuth genehmigten Dissertation zur Erlangung des akademischen
Grades Doktor der Naturwissenschaften (Dr. rer. nat.).














Promotionsgesuch eingereicht am: 07.10.2005
Wissenschaftliches Kolloquium am: 14.12.2006

Erster Gutachter: Prof. Dr. D. von Holst

Zweiter Gutachter: Prof. Dr. K. Hodges


















Only the earth endures.


















Meiner Mutter – dem Engel an meiner Seite

















Ein Teil dieser Arbeit wurde veröffentlicht:


Reichert, K.E., Heistermann, M., Hodges, J.K., Boesch, C. & Hohmann, G. 2002. What
females tell males about their reproductive status: Are morphological and behavioural cues
reliable signals of ovulation on bonobos (Pan paniscus)? Ethology, 108, 583-600. CONTENT I
Content
1 Introduction ............................................................................................................. 1
1.1 Menstrual cycles and sexual swelling patterns in bonobos............................................................ 3
1.2 Sexual swellings as a signal of ovulation ......................................................................................... 4
1.3 Sexual interactions between females................................................................................................ 7
1.4 Female social status......................................................................................................................... 11
2 Methods .................................................................................................................. 15
2.1 Data collection ................................................................................................................................. 15
2.1.1 Study animals.................. 15
2.1.1.1 Housing conditions....................................................................................................................... 17
2.1.1.2 Feeding......................................................................................................................................... 17
2.1.2 Collection of behavioural data .......................................................................................................... 18
2.1.3 behavioural data during feeding experiments.............................................................. 20
2.1.4 Scoring of the genital swelling.......................................................................................................... 21
2.1.5 Collection of faecal samples ................................................................................................... 21
2.2 Data analysis.................. 22
2.2.1 Analysis of behavioural data.......... 22
2.2.2 swelling data .................................................................................................................. 23
2.2.3 Hormone analysis.............................................................................................................................. 24
2.2.3.1 Sample preparation....................................................................................................................... 24
2.2.3.2 Extraction ..................................................................................................................................... 24
2.2.3.3 Enzyme immunoassays ................................................................................................................ 26
2.2.4 Duration of menstrual cycles............................................................................................................. 29
2.2.5 Determining ovulation and the follicular and luteal phase................................................................ 30
2.2.6 Validation of the 11-ketoetiocholanolone assay................................................................................ 31
2.2.6.1 Validation for chimpanzees.......................................................................................................... 32
2.2.6.2 Validation for bonobos................................................................................................................. 32
2.2.7 Analysis of 11-ketoetiocholanolone levels........................................................................................ 33
2.2.8 Statistical analysis ............................................................................................................................. 33
3 Results 35
3.1 Variability of menstrual cycles and swelling patterns ................................................................. 35
3.1.1 Influence of the reproductive status .................................................................................................. 35
3.1.2 Intermenstrual intervals and maximum swelling .............................................................................. 36
3.1.3 Determination of cycle phases from hormone excretion patterns ..................................................... 38
3.1.4 Duration of intermenstrual intervals and follicular and luteal phase................................................. 39
3.2 Reliability of sexual swellings as a signal of ovulation 40
3.2.1 The timing of ovulation during maximum tumescence..................................................................... 40
3.2.2 Patterns of sexual swelling and sexual behaviour ............................................................................. 42
3.2.2.1 Influence of the swelling phase on copulations............................................................................ 42
3.2.2.2 nce phase on other sexual interactions ....................................................... 44
3.2.3 Sexual behaviour and the fertile phase.............................................................................................. 45
3.2.4 Sexual interactions during the follicular and the luteal phase ........................................................... 46
3.3 Context and function of sexual interactions between females..................................................... 47
3.3.1 Influence of relatedness..................................................................................................................... 48
3.3.2 Formation or maintenance of alliances ............................................................................................. 49 II CONTENT

3.3.2.1 Preferred partners for genital rubbing and grooming....................................................................49
3.3.2.2 Alliance formation during the feeding experiments......................................................................50
3.3.2.3 ation in the context of conflicts...............................................................................51
3.3.2.4 Food sharing during the feeding experiment.................................................................................51
3.3.3 Reduction of female-female competition...........................................................................................53
3.3.4 Reconciliation between former opponents.........................................................................................56
3.3.5 Signal of social status ........................................................................................................................57
3.3.6 Regulation of social tension...............................................................................................................58
3.4 Behavioural and endocrine parameters of female social status...................................................62
3.4.1 Dominance hierarchies ......................................................................................................................62
3.4.2 Status-dependent access to monopolisable food sources...................................................................63
3.4.3 Validation of the 11-ketoetiocholanolone assay ................................................................................64
3.4.3.1 Chimpanzee .......