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Changes in group dynamics of an already established social group as a result of the integra)on of a new chimpanzee.
a
Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
b
Facultat d’Educació i Psicologia, Universitat de Girona, Girona, Spain
c
Unitat de Recerca i Etologia, Fundació Mona, Riudellots de la Selva, Spain
d
Institut Català de Paleoecologia Humana i Evolució Social, Tarragona, Spain Email:
[email protected]
Key Words: Behaviour; welfare; group dynamics; transfer; chimpanzees.
Sara OrNna, Jaume Parerab & Miquel Llorentec,d
1. INTRODUCTION
2. MATERIAL AND METHODS
Social structure in animals has an impact on the social dynamics and relaVonships among group members. It depends of severals factors such as age, group members, age group or subjects personality, among others. In the case of chimpanzees, and other primate species, changes in social structure mean changes in the quality and quanVty of social relaVonships. Although capVve selngs block natural changes in the social structures of animals, someVmes the management procedures lead to the transfer and moving of animals. Our objecVve was to assess whether an introducVon of a new male chimpanzee into a previously established mulVmale group had an impact on their social dynamics, acVvity budget and welfare. We proceed to the analysis of the relaVonships between established group members, as well as, the analysis of the frequency of their behaviours (Individual PosiVve, Individual NegaVve, Social AffiliaVve and Social AgonisVc) before and aber the introducVon of the subject.
2.1. SAMPLE The established group:
2.3 RECORDING AND PROCESSING OF DATA Type of sampling: Instantaneous Scan (20’:2) Sessions held: 979 Hours recorded: 326h Condi)ons: CondiVon 1 (pre-‐introducVon of new subject) CondiVon 2 (post-‐introducVon) Category Subcategory Type Abnormals NegaVves InacVvity Individual Self-‐directed LocomoVon PosiVves ManipulaVon Feeding Grooming
Marco 29 years Charli 24 years Bongo 13 years Toni 30 years
The introduced individual: Juan 10 years.
2.2 STUDY SITE
Fundació Mona (Riudellots de la Selva, Girona) Outdoor enclosures: 5.640 m2
Social play
Proximity related
Social
AffiliaVves
Other affiliaVve Dominance AgonisVcs
Submission Other agonisVc
Twice-‐Weight Associa)on Index: Tt / Tt + Ta + Tb
As:
Tt: number of observaVon periods where individual A and B were observed together. Ta: number of observaVon periods where individual A has been observed in absence of B. Tb: number of observaVon periods where individual B has been observed in absence of A.
2.4 DATA ANALYSIS Twice-‐Weight AssociaVon Index
1 Differences between Twice-‐Weight AssociaVon Index
Behavioural catalogue
and Experimental CondiVon (1 / 2) 2 Differences between Behavioural categories and Experimental CondiVon (1 / 2)
Generalized Linear Mixed Model1,2
3. RESULTS 3.1 DIFFERENCES TWICE-‐WEIGHT ASSOCIATION INDEX PRE (1) AND POST-‐INTRODUCTION (2)
3.2 DIFFERENCES BEHAVIOURAL REPERTORY PRE (1) AND POST-‐INTRODUCTION (2)
Rela)onship
F
Sig.
Bongo-‐Charly
0,011
0,916
Bongo-‐Marco
2,381
0,123
Bongo-‐Toni
0,813
0,637
Charli-‐Marco
0,007
0,936
Charli-‐Toni
1,086
0,298
Marco-‐Toni
1,72
0,190
Mean Twice-‐Weight Associa)on Index
0,1 0,09
Gen-‐11(1)
Apr-‐11(1)
May-‐11(1)
Jun-‐11(1)
Oct-‐11(1)
Gen-‐12(2)
Mar-‐12(2)
Apr-‐12(2)
May-‐12(2)
Bongo
0,08 0,07 0,06 0,05 0,04
Jun-‐12(2)
Jul-‐12(2)
Oct-‐12(2)
Nov-‐12(2)
Dec-‐12(2)
Gen-‐13(2)
Feb-‐13(2)
Mar-‐13(2)
0,03 0,02
F
Sig.
Individual PosiVve
0,913
0,34
Individual NegaVve
23,615
Social AffiliaVve Social AgonisVc
F
Sig.
Individual PosiVve
7,962
0,005*
0,00*
Individual NegaVve
7,466
0,006*
8,332
0,004*
Social AffiliaVve
13,227
0,000*
0,976
0,327
Social AgonisVc
0,033
0,855
F
Sig.
F
Sig.
Individual PosiVve
8,028
0,005*
Individual PosiVve
0,613
0,434
Individual NegaVve
6,142
0,013*
Individual NegaVve
0,173
0,678
Social AffiliaVve
6,768
0,009*
Social AffiliaVve
0,568
0,451
Social AgonisVc
1,443
0,23
Social AgonisVc
1,618
0,204
Marco
0,01 0
CHARLI-‐TONI
MARCO-‐TONI
0,1 0,09
Charli
Toni
Mean Twice-‐Weight Associa)on Index
0,08 0,07
Bongo's ac)vity budget
0,06 0,05
Charli's ac)vity budget
CONDITION 1
0,04 0,03 0,02 0,01 0
BONGO-‐MARCO
BONGO-‐TONI
CHALI-‐MARCO
CONDITION 1
CONDITION 2
0,7
0,7
0,6
0,6
0,5
0,5
0,4
0,4
0,3
0,3
0,2
0,2
0,1
0,1
0
INDIVIDUAL POSITIVE
INDIVIDUAL NEGATIVE
SOCIAL AFFILIATIVE
SOCIAL AGONISTIC
0
INDIVIDUAL POSITIVE
Marco's ac)vity budget
INDIVIDUAL NEGATIVE
SOCIAL AFFILIATIVE
CONDITION 2
SOCIAL AGONISTIC
Toni's ac)vity budget
CONDITION 1
CONDITION 2
1
CONDITION 1
CONDITION 2
0,4
0,9
0,35
0,8
0,3
0,7 0,6
0,25
0,5
0,2
0,4
0,15
0,3
0,1
0,2
0,05
0,1 0
INDIVIDUAL POSITIVE
INDIVIDUAL NEGATIVE
SOCIAL AFFILIATIVE
SOCIAL AGONISTIC
0
INDIVIDUAL POSITIVE
INDIVIDUAL NEGATIVE
SOCIAL AFFILIATIVE
SOCIAL AGONISTIC
4. DISCUSSION AND CONCLUSIONS 1. The introducVon of a new subject into an already established group does not significantly affect the strength of the relaVonships or links between previously established group members.
3. In none of the established group members have been affected agonisVc behaviour aber the introducVon of the new subject.
2. The introducVon of a new subject to established group affects the behavioural repertoire of the members. We observe an increase in negaVve behaviours and affiliaVve social behaviours.
4. The introducVon of the new subject produces a greater increase in posiVve and affiliaVve behaviours than negaVve and agonisVcs; indirectly producing an improvement in the welfare of group established members.
References
Acknowledgment
• Bode, N.W., Wood, A.J., Franks, D.W., 2011 The impact of social networks on collecVve moVon. Animal Behaviour 82, 29-‐38. • Kasper, C., Voelkl, B., 2009. A social network analysis of primate groups. Primates 50, 343-‐356. • Rox, A., Kapteijn, C., 2012. From solitary to social: The process of resocialisaVon of rescued primates. Eubacteria 30, Especial primates 1-‐3.
Fundació Mona. Ministerio de Economía y CompeVVvidad: HAR2012-‐32548
