Last update: : Tuesday 17 May 2016, by
Par : Palmyre Boucherie, IPHC-DEPE
Date : vendredi 20 mai 2016 à 13h
Lieu : IPHC, Amphithéâtre Grünewald, bâtiment 25
On a gradient of social complexity, birds are often considered as less complex than most mammals’ social species. Indeed, monogamy, widespread in birds, likely limits the diversity and the number of social relationships in which individual can be involved. However, in birds, some species like corvids live in groups all year round, often facing constant demographic changes (i.e. colonial dynamics). In addition, corvids are also well known for their cognitive and social abilities. They are attentive to other, and they can track and assess social relationships between group members. During my thesis, I explored the social structure and dynamic of captive adult rooks over three years, scrutinizing the behavioural mechanisms involved in several social processes (e.g. pair or extra-pair bond formation or dissolution, temporal dynamics of social relationships, establishment and dynamic of dominance relationships). I found that adult groups of rooks are not just an aggregation of pairs and that both pairs and secondary affiliations form the backbone of the social structure. In addition, I found that adult rooks do not necessarily pair for life, and have the ability to establish a strong new bond with another partner. Furthermore, I found that dominance relationships do exist in rooks groups. However, they were not clearly and consistently structured, questioning the existence of a hierarchical ranking in this species. Finally, I found that robust and consistent internal mechanisms sustain and modulate the dynamics of relationships, whatever the group composition. Overall, this results reveal how consistent internal processes shape rook social structure, and highlight the importance of considering extra-pair relationships in socially monogamous birds. By revealing the social flexibility of this cognitively advanced species, they widen our understanding of different forms of society in animals.