Interactional rules in captive Siskins (Carduelis spinus)

Abstract

A first step in any study on social organization is the analysis of interactions. Here, three factors affecting agonistic interactions: rank; sex and age, have been investigated to throw light on the organization of interactional nets. Interactional rates and patterns of direction have been analysed in more than 4,000 interactions between captive Siskins (Carduelis spinus). Four groups of different composition were used as different replicates to the study. Reproductive period was excluded. Subordinate individuals threatened dominants less than expected, and the more dominant the opponents were, the fewer threats they showed. Dominants threatened subordinates more than expected. Young and adult males interacted more than expected, young females interacted very few times with the rest of the group, and adult females received more threats from adult and young males than expected. There were three kinds of clusters of interaction: individuals of future pairs, severa1 males presumibly competing around one female, and high ranking individuals. Dynamics of reproduction and pairing relationships in cardueline finches are reviewed. Patterns of interaction found in this work seem to fit these dynamics. It is therefore proposed that interactions in wintering Siskins, not only organize hierarchy, but also have a pairing function.