Abstract (eng)
Socially living animals have to cope with a highly unpredictable and complex environment in which
the individuals compete for limited resources. In most social groups the access to these resources is
regulated by a dominance hierarchy established through repeated agonistic interactions. The more
dominant and higher ranking an individual the better its resource holding potential.
Social living involves not only agonistic relationships but also friendships between affiliated
individuals and often also relationships between kin. These diverse social dynamics can influence
information transmission between individuals and also social learning like local and stimulus
enhancement.
I tested positive effects of social dynamics on object manipulation in a social living bird species, the
Goffin cockatoo (Cacatua goffini). Using observational data I first calculated a dominance
hierarchy and affiliated relationships and then test dyads of dominant, affiliated and akin pairs in a
simple choice task using different object sets. My results show, that dominance hierarchy is highly
linear, with males at higher ranks than females. No social learning, neither on individual nor on
group level irrespective of the social condition (dominance, affiliated or akin) could be detected.
However, subjects showed a significant side bias and strong individual preferences for particular
objects.
My results on dominance hierarchy and its effects on behaviour are so far in accordance with what
has been found in other avian species. Contrary to previous studies on birds, the current lack of
social learning suggests that at least in this species social learning seems rather unimportant.
Furthermore, individual preferences seem to overpower the social influence of a demonstrating
individual. However, further investigation is necessary to ensure if this is a general finding or based
on the methodology used in this study.