Dominance Relationships in Jackdaws (Corvus Monedula)
AbstractDominance interactions (supplantings) of 26 jackdaws (Corvus monedula) living in a captive flock were recorded for a period of 2 years. The transitivity of the dominance hierarchy did not increase over time. Though there were 238 rank changes in course of the study, a portion of 6 % of all possible triads of the flock was always intransitive. Only 16.5% of the observed supplantings involved aggressive behaviour. There was no significant correlation between the body weight of a jackdaw and its dominance rank. Male-Male dyads had a disproportionally high frequency of dominance interactions and rank changes. Females were more likely to gain in rank in course of a rank change if their mate was already dominant to the opponent and to lose in rank if their mate was subordinate to the opponent. With the males there was no such tendency. Only 5.4% of the observed dominance interactions were temporary reversals with respect to the defined dominance relationship of a dyad. The probability of temporary reversals was increased if the mate of the supplanting jackdaw was present (less than 60 cm away) during the dominance interaction even though it did not interfere. When it was present, it joined the supplanting interaction in 10.0% of the cases. Breeding jackdaws had an increased percentage of reversed dominance interactions in front of their nest box. This site-related dominance was especially marked as soon as the female started to incubate.