Frequencies of agonistic behaviours as measures of aggression in chickens: A factor analysis

Abstract

Different types of aggressive behaviour have often been treated as comparable in measures of aggressiveness in chickens. Are these different forms of behaviour equivalent? Observations were made of behaviour in small mixed-sex groups of domestic chickens, from hatcing to 25 weeks of age. Threats and headpecks both tended to elicit avoidances, and retaliation was rare. However, leaps and horizontal threats tended to elicit other leaps. Factor analysis showed that threats and pecks tended to occur in the same dyadic relationships. Dyads with a high frequency of chases and waltzes, however, were not necessarity those with a high frequency of threats and pecks. The frequency of waltzing was dependent on the amount of crowing a male showed. The frequency of leaps and horizontal threats tended to be closely linked to the occurrence of running bouts rather than to the occurrence of threats and pecks.