Individual behavioural characteristics and dominance in aviary groups of great tits

In previous work we have shown that juvenile male great tits Parus major sh ow consistent behavioural differences in exploratory and aggressive behavio ur. Fast and superficial explorers (FE) won from slow and thorough explorer s (SE) during controlled pair-wise confrontations in small cages. The prese nt study assesses the relationship between early exploratory behaviour and later dominance in aviary groups of juvenile male great tits; such groups m ight approach natural conditions better than 'simple' pair-wise confrontati ons. Observations of nine aviary groups showed that a stable hierarchy is o nly established after a first dynamic phase of several days with many domin ance shifts and a peak in number of interactions. In seven other aviary gro ups we determined the dominance relationships between FE and SE. In a stabl e hierarchy, SE had on average a significantly higher dominance score than FE. This finding contrasts our previous results in pair-wise confrontations . However, on the first day in the aviary, FE had on average a higher domin ance score and initiated more fights than SE. This agrees with our previous results and indicates a gradual development of the situation in the stable hierarchy. Behavioural observations indicate that during this development, FE took more risks in their fighting behaviour and had more difficulty to cope with defeat than SE. In the stable hierarchy they either won or lost f rom all SE. SE were more cautious and had intermediate dominance scores in the stable hierarchy. These differences in fighting behaviour and the role of individual differences in exploratory behaviour and in coping with defea t are discussed as possible causes for the unexpected results of this study .