title: Development of social behaviour in chickens: A factor analysis.
abstract: Factor analysis was used to describe the week by week changes in the frequency of a wide range of behaviours of chickens. Oblique rotation resulting in correlated factors was compared with the more conventional orthogonal rotation, and was found to provide a clearer interpretation of the factors. Mixed sex groups of chickens were observed from hatching until sexual maturity, and the changes in the occurrence of agonistic behaviours could be described in terms of three factors. Factor 1 involved early sparring and running, but there was some doubt as to whether this should be labelled aggressive. Factor 2 involved non-reciprocated leaping, horizontal neck threats, and headpecks between males. Factor 3 involved threats and headpecks between males and females. Sexual development could be described by two factors; the first involving sexual development of the male, and the second the beginning of sexual interactions between males and females. Waltzes and rear approaches were associated with the sexual development of males, while chases were associated with sexual interactions. There was an increase in the frequency of prolonged male-male agonistic encounters when these sexual interactions began to occur.
authors.affiliation: Animal Behaviour Unit, Psychology Department, University of Queensland, St. Lucia, Qld 4067 Australia.
authors.forename: J
authors.initials: J
authors.lastname: Rushen